10-Q 1 tslx-20240331.htm 10-Q 10-Q
Q1--12-310001508655falsehttp://sixthstreetspecialtylending.com/20240331#NetChangeInUnrealizedGainsLossesOnInvestmentsAndForeignCurrencyTranslationhttp://sixthstreetspecialtylending.com/20240331#NetRealizedGainsLossesOnInvestmentsAndForeignCurrencyTranslationhttp://sixthstreetspecialtylending.com/20240331#NetChangeInUnrealizedGainsLossesOnInvestmentsAndForeignCurrencyTranslationhttp://sixthstreetspecialtylending.com/20240331#NetRealizedGainsLossesOnInvestmentsAndForeignCurrencyTranslation0001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. Series C Preferred Shares (1,816,295 shares) Initial Acquisition Date 4/8/20212023-01-012023-12-310001508655tslx:KyribaCorpMembertslx:RevolverMember2024-03-310001508655us-gaap:TreasuryStockCommonMember2024-03-310001508655Debt Investments Business Services ForeScout Technologies, Inc. First-lien loan ($5,476 par, due 8/2026) Initial Acquisition Date 7/1/2022 Reference Rate and Spread SOFR + 8.10% Interest Rate 13.41%2024-01-012024-03-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. 280,000 Series C Warrants Initial Acquisition Date 2/28/20202023-01-012023-12-310001508655us-gaap:CommonStockMember2023-03-310001508655Interest Rate Swap Company Receives SOFR + 2.54% Maturity Date 11/1/20242024-03-310001508655tslx:DelayedDrawMembertslx:SkylarkUkDebtcoLimitedMember2024-03-310001508655tslx:RevolvingCreditFacilityMaturityOnJuneTwelveTwoThousandAndTwentyEightMember2024-01-012024-03-310001508655tslx:ArtisanBidcoIncMembertslx:RevolverMember2023-12-310001508655tslx:SupplementalDividendMember2023-02-162023-02-160001508655Equity and Other Investments Structured Credit Ares CLO Ltd, Series 2021-59A Structured Product ($1,000par,due4/2034) Initial Acquisition Date 6/23/2022 Reference Rate and Spread SOFR+6.51% Interest Rate 11.84%2024-03-310001508655tslx:DelayedDrawAndRevolverMembertslx:NetwrixCorpMember2024-03-310001508655Debt Investments Financial Services PrimeRevenue, Inc. First-lien loan ($9,007 par, due 12/2024) Initial Acquisition Date 12/31/2018 Reference Rate and Spread SOFR + 7.10% Interest Rate 12.46%2023-01-012023-12-310001508655srt:MaximumMembercountry:FI2024-03-310001508655Debt Investments Human Resource Support Services PageUp People, Ltd. First-lien loan ($ 9,579 par, due 12/2025) Initial Acquisition Date 10/28/2021 Reference Rate and Spread S + 5.10% Interest Rate 10.43%2024-01-012024-03-310001508655us-gaap:AdditionalPaidInCapitalMember2024-03-310001508655Debt Investments Human Resource Support Services PayScale Holdings, Inc. First-lien loan ($71,196 par, due 5/2027) Initial Acquisition Date 5/3/2019 Reference Rate and Spread SOFR + 6.35% Interest Rate 11.70%2023-01-012023-12-310001508655Debt Investments Business Services ForeScout Technologies, Inc. First-lien loan ($5,476 par, due 8/2026) Initial Acquisition Date 7/1/2022 Reference Rate and Spread SOFR + 8.10% Interest Rate 13.41%2024-03-310001508655Debt Investments Internet Services Coupa Holdings, LLC First-lien loan ($43,191 par, due 2/2030) Initial Acquisition Date 2/27/2023 Reference Rate and Spread SOFR + 7.50% Interest Rate 12.86%2023-01-012023-12-310001508655Debt Investments Human Resource Support Services PageUp People, Ltd. First-lien loan (AUD 13,400 par, due 12/2025) Initial Acquisition Date 1/11/2018 Reference Rate and Spread B + 5.00% Interest Rate 9.36%2023-12-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. 633,376 Warrants Initial Acquisition Date 9/21/20182023-12-310001508655tslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Member2024-01-012024-03-3100015086552023-03-310001508655Debt Investments Education Kangaroo Bidco AS First-lien loan ($30,625 par, due 11/2030) Initial Acquisition Date 11/2/2023 Reference Rate and Spread SOFR + 7.50% Interest Rate 12.90%2024-01-012024-03-310001508655tslx:ArrowbuyerIncMembertslx:DelayedDrawMember2024-03-310001508655Interest Rate Swap Company Receives 6.125% Company Pays SOFR + 2.44% Maturity Date 3/1/20292024-01-012024-03-310001508655Debt Investments, Manufacturing, Skylark UK DebtCo Limited, First-lien loan (EUR 4,851 par, due 9/2030), Initial Acquisition Date 9/7/2023, Reference Rate and Spread, E + 5.75%, Interest Rate 9.65%2024-03-310001508655tslx:RevolvingCreditFacilityMaturityOnApril232027Member2024-03-310001508655Equity and Other Investments Human Resource Support Services Employment Hero Holdings Pty Ltd. Series E Preferred Shares (113,250 shares) Initial Acquisition Date 3/1/20222024-03-310001508655Equity and Other Investments Structured Credit Battalion CLO Ltd, Series 2021-21A Structured Product ($1,300par,due7/2034) Initial Acquisition Date 7/13/2022 Reference Rate and Spread SOFR+3.56% Interest Rate 8.96%2023-01-012023-12-310001508655us-gaap:IncomeApproachValuationTechniqueMembertslx:MezzanineDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputDiscountRateMember2024-03-310001508655tslx:RevolverMembertslx:DyeDurhamCorpMember2023-12-310001508655tslx:BusinessServicesMember2024-03-310001508655Debt Investments Oil, Gas and Consumable Fuels Murchison Oil and Gas, LLC First-lien loan ($24,637 par, due 6/2026) Initial Acquisition Date 6/30/2022 Reference Rate and Spread SOFR + 8.40% Interest Rate 13.72%2024-01-012024-03-310001508655Equity and Other Investments Business Services ReliaQuest, LLC Series A Preferred Stock (1,667 Units) Initial Acquisition Date 12/20/20232023-12-3100015086552018-01-012018-01-310001508655Debt Investments Retail and Consumer Products Cordance Operations, LLC First-lien loan ($49,543 par, due 7/2028) Initial Acquisition Date 7/25/2022 Reference Rate and Spread SOFR + 9.25% Interest Rate 14.66%2023-12-310001508655country:NO2024-03-310001508655tslx:DelayedDrawAndRevolverMembertslx:EdgeBidcoBVMember2023-12-310001508655Debt Investments Business Services OutSystems Luxco SARL First-lien loan (EUR 3,004 par, due 12/2028) Initial Acquisition Date 12/8/2022 Reference Rate and Spread E + 5.75% Interest Rate 9.59%2023-01-012023-12-310001508655Interest Rate Swap Company Receives 3.875% Company Pays SOFR + 2.72% Maturity Date 11/1/20242023-12-310001508655tslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputComparabilityAdjustmentMembersrt:WeightedAverageMemberus-gaap:MarketApproachValuationTechniqueMember2023-12-310001508655Equity and Other Investments Internet Services Bayshore Intermediate #2, L.P. Co-Invest Common Units (8,837,008 units) Initial Acquisition Date 10/1/20212023-01-012023-12-310001508655tslx:SouthMember2024-03-310001508655Equity and Other Investments Healthcare2024-03-310001508655country:LU2023-12-310001508655Debt Investments Healthcare BCTO Ace Purchaser, Inc. First-lien loan ($69,429 par, due 11/2027) Initial Acquisition Date 11/23/2020 Reference Rate and Spread SOFR + 7.45% Interest Rate 12.79%2024-03-310001508655tslx:NortheastMember2023-12-310001508655tslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Member2023-01-012023-03-310001508655Debt Investments Business Services Alpha Midco, Inc. First-lien loan ($68,885 par, due 8/2025) Initial Acquisition Date 8/15/2019 Reference Rate and Spread SOFR + 7.63% Interest Rate 12.97%2023-12-310001508655Debt Investments Education Kangaroo Bidco AS First-lien loan ($25,582 par, due 11/2030) Initial Acquisition Date 11/2/2023 Reference Rate and Spread SOFR + 7.50% Interest Rate 12.94%2023-01-012023-12-310001508655Equity and Other Investments Business Services Dye & Durham, Ltd. Common Shares (126,968 shares) Initial Acquisition Date 12/3/20212024-03-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. Series C Preferred Shares (1,816,295 shares) Initial Acquisition Date 4/8/20212024-03-310001508655tslx:PrimeRevenueIncMembertslx:RevolverMember2024-03-310001508655Debt Investments Financial Services Alaska Bidco Oy First-lien loan (EUR 727 par, due 5/2030) Initial Acquisition Date 5/30/2023 Reference Rate and Spread E + 6.25% Interest Rate 10.39%2023-01-012023-12-310001508655Equity and Other Investments Structured Credit Allegro CLO Ltd, Series 2018-1A, Structured Product ($1,000 par, due 6/2031) Initial Acquisition Date 5/26/2022 Reference Rate and Spread SOFR + 3.11% Interest Rate 8.43%2024-03-310001508655us-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMember2023-12-310001508655Equity and Other Investments Structured Credit CarVal CLO III Ltd, Series 2019-2A Structured Product ($1,000par,due7/2032) Initial Acquisition Date 6/30/2022 Reference Rate and Spread SOFR+6.70% Interest Rate 12.11%2023-12-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. Series D Preferred Shares (1,598,874 shares) Initial Acquisition Date 4/8/20212023-12-310001508655Debt Investments Financial Services Passport Labs, Inc. Convertible Promissory Note A ($1,086 par, due 8/2026) Initial Acquisition Date 3/2/2023 Reference Rate and Spread 8.00% Interest Rate 8.00%2023-12-310001508655Equity and Other Investments Structured Credit2024-03-310001508655Debt Investments Retail and Consumer Products Cordance Operations, LLC First-lien loan ($51,007 par, due 7/2028) Initial Acquisition Date 7/25/2022 Reference Rate and Spread SOFR + 9.18% Interest Rate 14.53%2024-03-310001508655Debt Investments Retail and Consumer Products Neuintel, LLC First-lien loan ($56,333 par, due 12/2026) Initial Acquisition Date 12/20/2021 Reference Rate and Spread SOFR + 7.60% Interest Rate 12.93%2024-03-310001508655Equity and Other Investments Automotive Clarience Technologies, LLC Class A Units (333 Units) Initial Acquisition Date 2/12/20242024-03-310001508655Debt Investments Retail and Consumer Products Tango Management Consulting, LLC First-lien revolving loan ($19 par, due 12/2027) Initial Acquisition Date 12/1/2021 Reference Rate and Spread SOFR + 6.85% Interest Rate 12.18%2024-01-012024-03-310001508655Derivative Interest Rate Swap2023-12-310001508655Debt Investments Transportation Project44, Inc. First-lien loan ($35,095 par, due 11/2027 Initial Acquisition Date 11/12/2021 Reference Rate and Spread SOFR + 6.40% Interest Rate 11.71%2024-03-310001508655Equity and Other Investments Structured CreditAres Loan Funding I Ltd, Series 2021-ALFA, Class E Structured Product ($1,000 par,due 10/2034) Initial Acquisition Date 6/24/2022 Reference Rate and Spread SOFR+6.96% Interest Rate 12.36%2023-01-012023-12-310001508655Debt Investments Manufacturing Skylark UK DebtCo Limited First-lien loan (EUR 4,851 par, due 9/2030) Initial Acquisition Date 9/7/2023 Reference Rate and Spread E + 6.25% Interest Rate 10.18%2023-01-012023-12-310001508655Equity and Other Investments Structured Credit Eaton CLO Ltd, Series 2015-1A Structured Product ($2,500par,due1/2030) Initial Acquisition Date 6/23/2022 Reference Rate and Spread SOFR+2.76% Interest Rate 8.18%2023-12-310001508655Debt Investments Oil, Gas and Consumable Fuels Laramie Energy, LLC First-lien loan ($27,317 par, due 2/2027) Initial Acquisition Date 2/21/2023 Reference Rate and Spread SOFR + 7.10% Interest Rate 12.46%2023-12-310001508655Debt Investments Communications Banyan Software Holdings, LLC First-lien loan ($29,739 par, due 10/2026) Initial Acquisition Date 1/27/2023 Reference Rate and Spread SOFR + 7.35% Interest Rate 12.71%2023-12-310001508655Debt Investments Human Resource Support Services PageUp People, Ltd. First-lien loan ($10,557 par, due 12/2025) Initial Acquisition Date 10/28/2021 Reference Rate and Spread SOFR + 5.10% Interest Rate 10.45%2023-01-012023-12-310001508655Equity and Other Investments Structured Credit MidOcean Credit CLO Ltd, Series 2018-9A Structured Product ($1,100 par, due 7/2031) Initial Acquisition Date 6/1/2022 Reference Rate and Spread SOFR+ 6.31% Interest Rate 11.63%2024-01-012024-03-310001508655Equity and Other Investments Structured Credit GoldenTree CLO Ltd, Series 2020-7A Structured Product ($1,000par,due4/2034) Initial Acquisition Date 6/17/2022 Reference Rate and Spread SOFR+6.76% Interest Rate 12.18%2023-01-012023-12-310001508655Debt Investments Financial Services Ibis Intermediate Co. First-lien loan ($1,201 par, due 5/2027) Initial Acquisition Date 5/28/2021 Reference Rate and Spread SOFR + 4.65% Interest Rate 10.04%2023-01-012023-12-310001508655Debt Investments Chemicals Erling Lux Bidco SARL First-lien loan (GBP 12,287 par, due 9/2028) Initial Acquisition Date 9/6/2022 Reference Rate and Spread S + 6.75% Interest Rate 11.98%2023-12-310001508655Debt Investments Hotel, Gaming and Leisure Equinox Holdings, Inc Second-lien loan ($2,066 par, due 6/2027) Initial Acquisition Date 3/13/2024 Reference Rate and Spread 16.00% Interest Rate 16.00% PIK2024-01-012024-03-310001508655tslx:DelayedDrawAndRevolverMembertslx:CordanceOperationsLlcMember2024-03-310001508655tslx:TwoThousandTwentySixNotesMember2023-01-012023-12-310001508655tslx:EquityAndOtherInvestmentsMember2024-01-012024-03-310001508655Debt Investments Internet Services Hippo XPA Bidco AB First-lien loan (SEK 78,125 par, due 2/2031) Initial Acquisition Date 2/20/2024 Reference Rate and Spread STIBOR + 6.50% Interest Rate 10.58% (incl. 3.50% PIK)2024-01-012024-03-310001508655Equity and Other Investments Structured Credit Allegro CLO Ltd, Series 2018-1A, Structured Product ($1,000 par, due 6/2031) Initial Acquisition Date 5/26/2022 Reference Rate and Spread SOFR + 3.11% Interest Rate 8.43%2024-01-012024-03-310001508655Debt Investments, Manufacturing, ASP Unifrax Holdings, Inc, Secured Note ($1226 par, due 9/2028) Initial Acquisition Date 12/19/2023 Reference Rate and Spread 5.25% Interest Rate 5.25%2024-03-310001508655Controlled Affiliated Investments IRGSE Holding Corp.2024-01-012024-03-310001508655Equity and Other Investments Education RMCF IV CIV XXXV, LP. Partnership Interest (11.94% ownership) Initial Acquisition Date 6/8/20212024-01-012024-03-310001508655Interest Rate Swap Company Pays SOFR + 2.17% Maturity Date 8/1/20262023-12-310001508655Equity and Other Investments Business Services2024-03-310001508655Debt Investments Human Resource Support Services Elysian Finco Ltd. First-lien loan ($20,087 par, due 1/2028) Initial Acquisition Date 1/31/2021 Reference Rate and Spread SOFR + 6.65% Interest Rate 12.03% (incl. 6.50% PIK)2024-01-012024-03-310001508655Interest Rate Swap Company Receives 2.50% Company Pays SOFR + 2.17% Maturity Date 8/1/20262023-01-012023-12-310001508655Debt Investments Insurance Disco Parent, Inc. First-lien loan ($4,545 par, due 3/2029) Initial Acquisition Date 3/30/2023 Reference Rate and Spread SOFR + 7.50% Interest Rate 12.89%2023-01-012023-12-310001508655us-gaap:UnfundedLoanCommitmentMember2023-03-310001508655Equity and Other Investments Structured Credit CIFC CLO Ltd, Series 2021-4A Structured Product ($1,000par,due7/2033)Initial Acquisition Date 7/14/2022 Reference Rate and Spread SOFR+6.26% Interest Rate 11.66%2023-12-310001508655Debt Investments Hotel, Gaming and Leisure IRGSE Holding Corp. First-lien loan ($30,261 par, due 6/2024) Initial Acquisition Date 12/21/2018 Reference Rate and Spread SOFR + 9.65% Interest Rate 15.00%2023-12-310001508655Debt Investments Healthcare2023-12-310001508655Equity and Other Investments Financial Services TradingScreen, Inc. Class A Units (600,000 units) Initial Acquisition Date 5/14/20212024-03-310001508655tslx:RevolverMembertslx:WranglerTopcoLlcMember2024-03-310001508655Controlled Affiliated Investments2023-01-012023-12-310001508655Equity and Other Investments Human Resource Support Services Axonify, Inc. Class A-1 Units (3,780,000 units) Initial Acquisition Date 5/5/20212024-03-310001508655Equity and Other Investments Internet Services Piano Software, Inc. Series C-1 Preferred Shares (418,527 shares) Initial Acquisition Date 12/22/20212024-01-012024-03-310001508655Debt Investments Business Services Artisan Bidco, Inc First-lien loan (EUR 17,735 par, due 11/2029) Initial Acquisition Date 11/7/2023 Reference Rate and Spread E + 7.00% Interest Rate 10.96%2023-01-012023-12-310001508655Debt Investments Automotive Truck-Lite Co., LLC First-lien loan ($40,437 par, due 2/2031) Initial Acquisition Date 2/13/2024 Reference Rate and Spread SOFR + 5.75% Interest Rate 11.06%2024-01-012024-03-310001508655Debt Investments Business Services Dye & Durham Corp. First-lien revolving loan (CAD 1,086 par, due 12/2026) Initial Acquisition Date 12/3/2021 Reference Rate and Spread C + 5.75% Interest Rate 11.20%2023-12-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. Series C Preferred Shares (1,915,114 shares) Initial Acquisition Date 10/13/20202024-03-310001508655tslx:StructuredCreditInvestmentsMember2023-01-012023-12-310001508655us-gaap:FairValueInputsLevel3Membertslx:SecondLienDebtInvestmentsMember2024-03-310001508655Debt Investments Internet Services EDB Parent, LLC First-lien loan ($65,167 par, due 7/2028) Initial Acquisition Date 7/7/2022 Reference Rate and Spread SOFR + 6.75% Interest Rate 12.08%2024-03-310001508655Debt Investments Human Resource Support Services Axonify, Inc. First-lien loan ($42,299 par, due 5/2027) Initial Acquisition Date 5/5/2021 Reference Rate and Spread SOFR + 7.65% Interest Rate 12.92%2024-03-310001508655Debt Investments Internet Services Lithium Technologies, LLC First-lien loan ($57,665 par, due 1/2025) Initial Acquisition Date 10/3/2017 Reference Rate and Spread SOFR + 9.00% Interest Rate 14.39% (incl. 4.50% PIK)2023-01-012023-12-310001508655tslx:BlueSnapIncMembertslx:RevolverMember2023-12-310001508655Debt Investments Transportation2023-12-310001508655Debt Investments Healthcare BCTO Ace Purchaser, Inc. Second-lien loan ($5,854 par, due 1/2030) Initial Acquisition Date 1/23/2023 Reference Rate and Spread SOFR + 10.70% Interest Rate 16.02% PIK2024-03-310001508655Equity and Other Investments Business Services ReliaQuest, LLC Series A Preferred Stock (1,667 Units) Initial Acquisition Date 12/20/20232023-01-012023-12-310001508655Equity and Other Investments Internet Services Piano Software, Inc. Series C-2 Preferred Shares (27,588 shares) Initial Acquisition Date 11/18/20222024-01-012024-03-310001508655Interest Rate Swap Company Receives 3.875% Company Pays SOFR + 2.72% Maturity Date 11/1/20242024-01-012024-03-310001508655tslx:NonControlledNonAffiliatedInvestmentsMember2024-03-310001508655Debt Investments Retail and Consumer Products Neuintel, LLC First-lien loan ($56,333 par, due 12/2026) Initial Acquisition Date 12/20/2021 Reference Rate and Spread SOFR + 7.60% Interest Rate 12.93%2024-01-012024-03-310001508655tslx:TwentyTwentyNineNotesMember2024-01-012024-03-310001508655Debt Investments Healthcare SL Buyer Corp. First-lien loan ($31,475 par, due 7/2029) Initial Acquisition Date 7/7/2023 Reference Rate and Spread SOFR + 7.00% Interest Rate 12.36%2023-01-012023-12-310001508655tslx:HotelGamingAndLeisureMember2023-12-310001508655Debt Investments Business Services Crewline Buyer, Inc. First-lien loan ($56,324 par, due 11/2030) Initial Acquisition Date 11/8/2023 Reference Rate and Spread SOFR + 6.75% Interest Rate 12.10%2023-12-310001508655Debt Investments Internet Services Coupa Holdings, LLC First-lien loan ($43,191 par, due 2/2030) Initial Acquisition Date 2/27/2023 Reference Rate and Spread SOFR + 7.50% Interest Rate 12.81%2024-01-012024-03-310001508655Debt Investments Financial Services Alaska Bidco Oy First-lien loan (EUR 727 par, due 5/2030) Initial Acquisition Date 5/30/2023 Reference Rate and Spread E + 6.25% Interest Rate 10.39%2023-12-310001508655tslx:BlueSnapIncMembertslx:RevolverMember2024-03-310001508655Debt Investments Business Services Wrangler TopCo, LLC First-lien loan ($4,153 par, due 7/2029) Initial Acquisition Date 7/7/2023 Reference Rate and Spread SOFR + 7.50% Interest Rate 12.82%2024-01-012024-03-310001508655Interest Rate Swap, Cash collateral2023-12-310001508655Debt Investments Financial Services BTRS Holdings, Inc. First-lien revolving loan ($2,410 par, due 12/2028) Initial Acquisition Date 12/16/2022 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.58%2024-01-012024-03-310001508655Equity and Other Investments Education RMCF IV CIV XXXV, LP. Partnership Interest (11.94% ownership) Initial Acquisition Date 6/8/20212023-12-310001508655Debt Investments Oil, Gas and Consumable Fuels Murchison Oil and Gas, LLC First-lien loan ($27,849 par, due 6/2026) Initial Acquisition Date 6/30/2022 Reference Rate and Spread SOFR + 8.65% Interest Rate 14.00%2023-12-310001508655Debt Investments Transportation Project44, Inc. First-lien loan ($35,139 par, due 11/2027) Initial Acquisition Date 11/12/2021 Reference Rate and Spread SOFR + 6.40% Interest Rate 11.78%2023-01-012023-12-310001508655tslx:FirstLienDebtInvestmentsMember2024-03-310001508655us-gaap:DomesticCountryMember2023-01-012023-12-310001508655Debt Investments Human Resource Support Services Madcap Software, Inc First-lien loan ($32,419 par, due 12/2026) Initial Acquisition Date 12/15/2023 Reference Rate and Spread SOFR + 6.10% Interest Rate 11.43%2024-01-012024-03-310001508655Debt Investments Transportation Marcura Equities LTD First-lien revolving loan ($1,667 par, due 8/2029) Initial Acquisition Date 8/11/2023 Reference Rate and Spread SOFR + 7.00% Interest Rate 12.18%2024-03-310001508655Debt Investments Financial Services Ibis Intermediate Co. First-lien loan ($1,197 par, due 5/2027) Initial Acquisition Date 5/28/2021 Reference Rate and Spread SOFR + 4.65% Interest Rate 9.99%2024-01-012024-03-310001508655Debt Investments Oil, Gas and Consumable Fuels2023-12-310001508655Interest Rate Swap Company Pays SOFR + 2.51% Maturity Date 11/1/20242023-12-310001508655Debt Investments Business Services Price Fx Inc. First-lien loan (EUR 910 par, due 10/2029) Initial Acquisition Date 10/27/2023 Reference Rate and Spread E + 7.00% Interest Rate 10.94%2023-01-012023-12-310001508655tslx:AlaskaBidcoOyMembertslx:DelayedDrawAndRevolverMember2024-03-310001508655tslx:InterestRateSwapFiveMember2024-01-012024-03-310001508655Debt Investments Business Services ExtraHop Networks, Inc. First-lien loan ($68,247 par, due 7/2027) Initial Acquisition Date 7/22/2021 Reference Rate and Spread SOFR + 7.60% Interest Rate 12.93%2024-01-012024-03-310001508655Debt Investments Retail and Consumer Products Tango Management Consulting, LLC First-lien revolving loan ($19 par, due 12/2027) Initial Acquisition Date 12/1/2021 Reference Rate and Spread SOFR + 6.85% Interest Rate 12.18%2024-03-310001508655Equity and Other Investments Retail and Consumer Products Copper Bidco, LLC Trust Certificates (996,958 Certificates) Initial Acquisition Date 1/30/20212024-01-012024-03-310001508655tslx:MarketingServicesMember2023-12-310001508655Debt Investments Communications Celtra Technologies, Inc. First-lien loan ($28,851 par, due 11/2026) Initial Acquisition Date 11/19/2021 Reference Rate and Spread SOFR + 5.75% Interest Rate 11.08%2024-01-012024-03-310001508655Equity and Other Investments Communications Celtra Technologies, Inc. Class A Units (1,250,000 units) Initial Acquisition Date 11/19/20212023-01-012023-12-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. 633,376 Warrants Initial Acquisition Date 9/21/20182024-01-012024-03-310001508655Equity and Other Investments Structured Credit Gulf Stream Meridian, Series 2021-6A Structured Product ($2,000par,due1/2037) Initial Acquisition Date 9/12/2022 Reference Rate and Spread SOFR+6.62% Interest Rate 11.93%2023-01-012023-12-310001508655tslx:RevolvingCreditFacilityMaturityOnFebruary42026Member2024-04-242024-04-240001508655Equity and Other Investments Structured Credit Southwick Park CLO Ltd, Series 2019-4A Structured Product ($1,000 par,due 7/2032) Initial Acquisition Date 5/25/2022 Reference Rate and Spread SOFR+ 6.51% Interest Rate 11.83%2024-01-012024-03-310001508655us-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:SecondLienDebtInvestmentsMembersrt:MinimumMemberus-gaap:MeasurementInputDiscountRateMember2024-03-310001508655Debt Investments Manufacturing ASP Unifrax Holdings, Inc. Secured Note ($91 par, due 9/2028) Initial Acquisition Date 12/19/2023 Reference Rate and Spread 5.25% Interest Rate 5.25%2023-12-310001508655Equity and Other Investments Structured Credit CarVal CLO III Ltd, Series 2019-2A Structured Product ($1,000par,due7/2032) Initial Acquisition Date 6/30/2022 Reference Rate and Spread SOFR+6.70% Interest Rate 12.02%2024-03-310001508655Debt Investments Office Products USR Parent, Inc. ABL FILO term loan ($17,000 par, due 4/2027) Initial Acquisition Date 4/25/2022 Reference Rate and Spread SOFR + 6.50% Interest Rate 11.84%2023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:FullsteamOperationsLlcMember2024-03-310001508655Debt Investments Retail and Consumer Products Bed Bath and Beyond Inc. Super-Priority DIP term loan ($4,550 par, due 9/2024) Initial Acquisition Date 4/24/2023 Reference Rate and Spread SOFR + 7.90% Interest Rate 13.23%2024-03-310001508655Equity and Other Investments Structured Credit Wind River CLO Ltd, Series 2018-3A Structured Product ($2,000par,due 1/2031) Initial Acquisition Date 12/12/2022 Reference Rate and Spread SOFR+ 5.91% Interest Rate 11.23%2024-03-310001508655Debt Investments Retail and Consumer Products2023-12-310001508655us-gaap:SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMembertslx:TwoThousandTwentyEightNotesMember2023-01-012023-12-310001508655Debt Investments Human Resource Support Services Employment Hero Holdings Pty Ltd. First-lien loan (AUD 50,000 par, due 12/2026) Initial Acquisition Date 12/6/2021 Reference Rate and Spread B + 6.25% Interest Rate 10.67%2023-12-310001508655Equity and Other Investments Business Services Warrior TopCo LP Class A Units (423,728 units) Initial Acquisition Date 7/7/20232023-12-310001508655tslx:DelayedDrawMembertslx:AxonifyIncMember2023-12-310001508655Equity and Other Investments Structured Credit Pikes Peak CLO, Series 2021-9A Structured Product ($2,000 par,due 10/2034) Initial Acquisition Date 8/31/2022 Reference Rate and Spread SOFR+ 6.84% Interest Rate 12.23%2023-12-310001508655Debt Investments Financial Services BTRS Holdings, Inc. First-lien loan ($47,526 par, due 12/2028) Initial Acquisition Date 12/16/2022 Reference Rate and Spread SOFR + 8.00% Interest Rate 13.33%2024-03-310001508655tslx:DelayedDrawAndRevolverMembertslx:BtrsHoldingIncMember2023-12-310001508655Debt Investments Chemicals Erling Lux Bidco SARL First-lien revolving loan (GBP 312 par, due 9/2028) Initial Acquisition Date 9/6/2022 Reference Rate and Spread S + 6.75% Interest Rate 11.98%2023-01-012023-12-310001508655Debt Investments Internet Services Piano Software, Inc. First-lien loan ($52,048 par, due 2/2026) Initial Acquisition Date 2/25/2021 Reference Rate and Spread SOFR + 7.85% Interest Rate 13.18% (incl.1.94% PIK)2024-03-310001508655tslx:DelayedDrawAndRevolverMembertslx:ExtraHopNetworksIncMember2024-03-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. Series C Preferred Shares (1,915,114 shares) Initial Acquisition Date 10/13/20202023-01-012023-12-310001508655Debt Investments Business Services Price Fx Inc. First-lien loan (EUR 910 par, due 10/2029) Initial Acquisition Date 10/27/2023 Reference Rate and Spread E + 7.00% Interest Rate 10.93%2024-01-012024-03-310001508655Equity and Other Investments Internet Services SMA Technologies Holdings, LLC Class B Units (923,250 shares) Initial Acquisition Date 11/21/20222023-01-012023-12-310001508655Debt Investments Manufacturing ASP Unifrax Holdings, Inc. Unsecured Note ($1,059 par, due 9/2029) Initial Acquisition Date 8/31/2023 Reference Rate and Spread 7.50% Interest Rate 7.50%2023-12-310001508655Debt Investments Retail and Consumer Products2024-03-310001508655tslx:RevolvingCreditFacilityMaturityOnApril232027Member2024-04-240001508655country:AU2024-03-310001508655Debt Investments Human Resource Support Services PrimePay Intermediate, LLC First-lien loan ($34,375 par, due 12/2026) Initial Acquisition Date 12/17/2021 Reference Rate and Spread SOFR + 7.15% Interest Rate 12.54%2023-01-012023-12-310001508655Debt Investments Human Resource Support Services Madcap Software, Inc. First-lien loan ($32,500 par, due 12/2026) Initial Acquisition Date 12/15/2023 Reference Rate and Spread SOFR + 6.10% Interest Rate 11.46%2023-01-012023-12-310001508655Debt Investments Retail and Consumer Products American Achievement, Corp. First-lien loan ($27,003 par, due 9/2026) Initial Acquisition Date 9/30/2015 Reference Rate and Spread SOFR + 6.35% Interest Rate 11.68% (incl. 11.18% PIK)2024-01-012024-03-310001508655Equity and Other Investments Structured Credit Octagon 57 LLC, Series 2021-1A Structured Product ($1,000 par, due 10/2034) Initial Acquisition Date 5/24/2022 Reference Rate and Spread SOFR+ 6.86% Interest Rate 12.26%2023-12-310001508655us-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMembersrt:MinimumMemberus-gaap:MeasurementInputDiscountRateMember2024-03-310001508655tslx:DelayedDrawAndRevolverMembertslx:ApteanIncMember2024-03-310001508655Debt Investments Hotel, Gaming and Leisure2023-12-310001508655tslx:EquityAndOtherInvestmentsMember2023-01-012023-03-310001508655Equity and Other Investments Internet Services SMA Technologies Holdings, LLC Class A Units (1,300 shares) Initial Acquisition Date 11/21/20222023-12-310001508655Debt Investments Business Services Netwrix Corp First-lien loan ($46,358 par, due 6/2029) Initial Acquisition Date 6/9/2022 Reference Rate and Spread SOFR + 5.00% Interest Rate 10.30%2024-03-310001508655Equity and Other Investments Education EMS Linq, Inc. Class B Units (5,522,526 units) Initial Acquisition Date 12/22/20212023-12-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. 106,592 Series D Warrants Initial Acquisition Date 4/8/20212023-01-012023-12-310001508655tslx:PassportLabsIncMembertslx:RevolverMember2024-03-310001508655Equity and Other Investments Business Services Dye & Durham, Ltd. Common Shares (126,968 shares) Initial Acquisition Date 12/3/20212023-01-012023-12-310001508655Equity and Other Investments Retail and Consumer Products Copper Bidco, LLC Trust Certificates (996,958 Certificates) Initial Acquisition Date 1/30/20212023-12-310001508655Debt Investments Business Services ExtraHop Networks, Inc. First-lien loan ($66,197 par, due 7/2027) Initial Acquisition Date 7/22/2021 Reference Rate and Spread SOFR + 7.60% Interest Rate 12.96%2023-01-012023-12-310001508655Equity and Other Investments Financial Services Passport Labs, Inc. 17,534 Warrants Initial Acquisition Date 4/28/20212024-01-012024-03-310001508655tslx:InternetServicesMember2024-03-310001508655Equity and Other Investments Structured Credit Octagon 57 LLC, Series 2021-1A Structured Product ($1,000 par, due 10/2034) Initial Acquisition Date 5/24/2022 Reference Rate and Spread SOFR+ 6.86% Interest Rate 12.18%2024-01-012024-03-310001508655tslx:TwoThousandTwentyEightNotesMember2023-08-140001508655Debt Investments Financial Services BCTO Bluebill Buyer, Inc. First-lien loan ($28,640 par, due 7/2029) Initial Acquisition Date 7/20/2023 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.60%2023-12-310001508655Debt Investments Business Services Alpha Midco, Inc. First-lien loan ($68,885 par, due 8/2025) Initial Acquisition Date 8/15/2019 Reference Rate and Spread SOFR + 7.63% Interest Rate 12.97%2023-01-012023-12-310001508655us-gaap:FairValueInputsLevel1Member2023-12-310001508655Debt Investments2024-03-310001508655tslx:PingIdentityCorporationMembertslx:RevolverMember2024-03-310001508655Debt Investments Healthcare Merative L.P. First-lien loan ($70,103 par, due 6/2028) Initial Acquisition Date 6/30/2022 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.56%2024-03-310001508655Equity and Other Investments Business Services Newark FP Co-Invest, L.P. Partnership (2,527,719 units) Initial Acquisition Date 11/8/20232023-12-310001508655us-gaap:RevolvingCreditFacilityMembersrt:MaximumMember2024-03-310001508655Debt Investments Education Astra Acquisition Corp. Second-lien loan ($43,479 par, due 10/2029) Initial Acquisition Date 10/22/2021 Reference Rate and Spread SOFR + 9.14% Interest Rate 14.44%2024-03-310001508655Debt Investments Retail and Consumer Products Bed Bath and Beyond Inc. Super-Priority DIP term loan ($4,739 par, due 9/2024) Initial Acquisition Date 4/24/2023 Reference Rate and Spread SOFR + 7.90% Interest Rate 13.26%2023-12-310001508655Debt Investments Internet Services LeanTaaS Holdings, Inc. First-lien loan ($39,426 par, due 7/2028) Initial Acquisition Date 7/12/2022 Reference Rate and Spread SOFR + 7.50% Interest Rate 12.81%2024-03-310001508655Equity and Other Investments Hotel, Gaming and Leisure2024-03-310001508655Debt Investments Business Services Galileo Parent, Inc. First-lien loan ($64,742 par, due 5/2030) Initial Acquisition Date 5/3/2023 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.60%2023-01-012023-12-310001508655Interest Rate Swap, Cash collateral2024-03-310001508655Debt Investments Financial Services CLGF Holdco 2, LLC Second-lien loan ($3,357 par, due 11/2028) Initial Acquisition Date 11/7/2023 Reference Rate and Spread SOFR + 12.00% Interest Rate 17.35%2023-12-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. Series D Preferred Shares (1,240,740 shares) Initial Acquisition Date 5/11/20212023-12-310001508655Debt Investments Education Destiny Solutions Parent Holding Company First-lien loan ($59,400 par, due 6/2026) Initial Acquisition Date 6/8/2021 Reference Rate and Spread SOFR + 5.85% Interest Rate 11.18%2024-03-310001508655Debt Investments, Manufacturing, Skylark UK DebtCo Limited, First-lien loan (EUR 4,851 par, due 9/2030), Initial Acquisition Date 9/7/2023, Reference Rate and Spread, E + 5.75%, Interest Rate 9.65%2024-01-012024-03-310001508655tslx:InterestRateSwapFiveMember2023-01-012023-03-310001508655Debt Investments Internet Services Bayshore Intermediate #2, L.P. First-lien loan ($37,064 par, due 10/2028) Initial Acquisition Date 10/1/2021 Reference Rate and Spread SOFR + 7.60% Interest Rate 12.92 PIK%2024-01-012024-03-310001508655Debt Investments Healthcare BCTO Ace Purchaser, Inc. First-lien loan ($69,231 par, due 11/2027) Initial Acquisition Date 11/23/2020 Reference Rate and Spread SOFR + 7.45% Interest Rate 12.84%2023-12-310001508655tslx:BaseDividendMember2024-02-150001508655Debt Investments Financial Services Ibis US Blocker Co. First-lien loan ($16,514 par, due 5/2028) Initial Acquisition Date 5/28/2021 Reference Rate and Spread SOFR + 8.40% Interest Rate 13.74% (PIK)2024-03-310001508655srt:MaximumMembercountry:FI2023-12-310001508655tslx:TwoThousandTwentySixNotesMember2021-02-030001508655Debt Investments Business Services Crewline Buyer, Inc. First-lien loan ($56,324 par, due 11/2030) Initial Acquisition Date 11/8/2023 Reference Rate and Spread SOFR + 6.75% Interest Rate 12.10%2023-01-012023-12-310001508655tslx:StructuredCreditInvestmentsMember2024-01-012024-03-310001508655tslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMemberus-gaap:MeasurementInputComparabilityAdjustmentMemberus-gaap:MarketApproachValuationTechniqueMember2024-03-310001508655Debt Investments Hotel, Gaming and Leisure Equinox Holdings, Inc Second-lien loan ($2,066 par, due 6/2027) Initial Acquisition Date 3/13/2024 Reference Rate and Spread 16.00% Interest Rate 16.00% PIK2024-03-310001508655Interest Rate Swap Company Pays SOFR + 2.51% Maturity Date 11/1/20242024-03-310001508655Debt Investments Financial Services Ibis US Blocker Co. First-lien loan ($15,958 par, due 5/2028) Initial Acquisition Date 5/28/2021 Reference Rate and Spread SOFR + 8.40% Interest Rate 13.79% (PIK)2023-01-012023-12-310001508655Debt Investments Human Resource Support Services bswift, LLC First-lien loan ($44,246 par, due 11/2028) Initial Acquisition Date 11/7/2022 Reference Rate and Spread SOFR + 6.38% Interest Rate 11.70%2024-01-012024-03-310001508655Equity and Other Investments Structured Credit Allegro CLO Ltd, Series 2018-1A, Structured Product ($1,000 par, due 6/2031) Initial Acquisition Date 5/26/2022 Reference Rate and Spread SOFR + 3.11% Interest Rate 8.51%2023-01-012023-12-310001508655tslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputComparabilityAdjustmentMemberus-gaap:MarketApproachValuationTechniqueMember2023-12-310001508655Debt Investments Financial Services Kyriba Corp. First-lien loan (EUR 11,158 par, due 4/2028) Initial Acquisition Date 12/21/2023 Reference Rate and Spread E + 8.50% Interest Rate 12.44 (incl. 8.50% PIK)2024-01-012024-03-310001508655tslx:DelayedDrawAndRevolverMembertslx:BtrsHoldingIncMember2024-03-310001508655Debt Investments Internet Services Arrow Buyer, Inc. First-lien loan ($33,125 par, due 7/2030) Initial Acquisition Date 6/30/2023 Reference Rate and Spread SOFR + 6.50% Interest Rate 11.85%2023-01-012023-12-310001508655Controlled Affiliated Investments IRGSE Holding Corp.2024-03-310001508655Debt Investments Healthcare BCTO Ace Purchaser, Inc. First-lien loan ($69,429 par, due 11/2027) Initial Acquisition Date 11/23/2020 Reference Rate and Spread SOFR + 7.45% Interest Rate 12.79%2024-01-012024-03-310001508655tslx:DelayedDrawMembertslx:BCTOAcePurchaserIncMember2024-03-310001508655Debt Investments Financial Services PrimeRevenue, Inc. First-lien loan ($7,007 par, due 12/2024) Initial Acquisition Date 12/31/2018 Reference Rate and Spread SOFR + 7.10% Interest Rate 12.43%2024-03-310001508655country:NL2024-03-310001508655Equity and Other Investments Business Services Newark FP Co-Invest, L.P. Partnership (2,527,719 Units) Initial Acquisition Date 11/8/20232024-03-310001508655Equity and Other Investments Structured Credit CIFC CLO Ltd, Series 2021-4A Structured Product ($1,000par,due7/2033)Initial Acquisition Date 7/14/2022 Reference Rate and Spread SOFR+6.26% Interest Rate 11.66%2023-01-012023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:ElysianFincoLtdMember2024-03-310001508655Debt Investments Automotive Bestpass, Inc. First-lien loan ($44,800 par, due 5/2029) Initial Acquisition Date 5/26/2023 Reference Rate and Spread SOFR + 5.75% Interest Rate 11.11%2023-01-012023-12-310001508655Equity and Other Investments Marketing Services Validity, Inc. Series A Preferred Shares (3,840,000 shares) Initial Acquisition Date 5/31/20182024-01-012024-03-310001508655Debt Investments Financial Services Volante Technologies, Inc. First-lien loan ($2,604 par, due 9/2028) Initial Acquisition Date 9/29/2023 Reference Rate and Spread 16.50% Interest Rate 16.50% PIK2023-01-012023-12-310001508655Equity and Other Investments Business Services Newark FP Co-Invest, L.P. Partnership (2,527,719 Units) Initial Acquisition Date 11/8/20232024-01-012024-03-310001508655Equity and Other Investments Structured Credit Eaton CLO Ltd, Series 2020-1A Structured Product ($1,000par,due10/2034) Initial Acquisition Date 8/11/2022 Reference Rate and Spread SOFR+6.51% Interest Rate 11.83%2024-03-310001508655Debt Investments Financial Services Bear OpCo, LLC First-lien loan ($21,392 par, due 10/2024) Initial Acquisition Date 10/10/2019 Reference Rate and Spread SOFR + 7.65% Interest Rate 13.01%2023-12-310001508655us-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMembersrt:MinimumMemberus-gaap:MeasurementInputDiscountRateMember2023-12-310001508655us-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMembersrt:WeightedAverageMember2024-03-310001508655Equity and Other Investments Structured Credit Wind River CLO Ltd, Series 2014-2A Structured Product ($1,500par,due 1/2031) Initial Acquisition Date 6/23/2022 Reference Rate and Spread SOFR+ 3.16% Interest Rate 8.56%2023-01-012023-12-310001508655Equity and Other Investments Human Resource Support Services Axonify, Inc. Class A-1 Units (3,780,000 units) Initial Acquisition Date 5/5/20212024-01-012024-03-310001508655Equity and Other Investments2024-03-310001508655us-gaap:CommonStockMember2023-05-150001508655country:FI2024-03-310001508655Equity and Other Investments Oil, Gas and Consumable Fuels Murchison Oil and Gas, LLC Preferred Units (13,355 units) Initial Acquisition Date 6/30/20222024-03-310001508655tslx:RevolverMembertslx:HeritageEnvironmentalServicesIncMember2024-03-310001508655Equity and Other Investments Human Resource Support Services Axonify, Inc. Class A-1 Units (3,780,000 units) Initial Acquisition Date 5/5/20212023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:HornetsecurityHoldingGmbhMember2023-12-310001508655Debt Investments Business Services Artisan Bidco, Inc First-lien loan (EUR 17,691 par, due 11/2029) Initial Acquisition Date 11/7/2023 Reference Rate and Spread E + 7.00% Interest Rate 10.92%2024-03-310001508655Debt Investments Insurance Disco Parent, Inc. First-lien loan ($4,545 par, due 3/2029) Initial Acquisition Date 3/30/2023 Reference Rate and Spread SOFR + 7.50% Interest Rate 12.84%2024-03-310001508655Debt Investments Communications Babylon Finco Limited First-lien loan ($1,557 par, due 1/2031) Initial Acquisition Date 1/26/2024 Reference Rate and Spread SOFR + 6.25% Interest Rate 11.57%2024-01-012024-03-310001508655Debt Investments Financial Services Ibis Intermediate Co. First-lien loan ($1,197 par, due 5/2027) Initial Acquisition Date 5/28/2021 Reference Rate and Spread SOFR + 4.65% Interest Rate 9.99%2024-03-310001508655Debt Investments Chemicals Erling Lux Bidco SARL First-lien loan (EUR 7,239 par, due 9/2028) Initial Acquisition Date 9/6/2022 Reference Rate and Spread E + 6.75% Interest Rate 10.70%2023-01-012023-12-310001508655Equity and Other Investments Human Resource Support Services bswift, LLC Class A-1 Units (2,393,509 units) Initial Acquisition Date 11/7/20222024-03-310001508655tslx:InvestmentAdvisoryAgreementMember2024-01-012024-03-310001508655Debt Investments, Manufacturing, ASP Unifrax Holdings, Inc, Unsecured Note ($1,059 par, due 9/2029), Initial Acquisition Date 8/31/2023, Reference Rate and Spread, 7.50%, Interest Rate 7.50%2024-03-310001508655Debt Investments Business Services OutSystems Luxco SARL First-lien loan (EUR 3,004 par, due 12/2028) Initial Acquisition Date 12/8/2022 Reference Rate and Spread E + 5.75% Interest Rate 9.59%2023-12-310001508655Debt Investments Internet Services Higher Logic, LLC First-lien loan ($52,216 par, due 1/2025) Initial Acquisition Date 6/18/2018 Reference Rate and Spread SOFR + 6.25% Interest Rate 11.56%2024-03-310001508655Debt Investments Business Services Dye & Durham Corp. First-lien loan (CAD 37,874 par, due 12/2027) Initial Acquisition Date 12/3/2021 Reference Rate and Spread C + 5.75% Interest Rate 11.20%2023-01-012023-12-310001508655Equity and Other Investments Structured Credit Magnetite CLO Ltd, Series 2021-30A Structured Product ($1,000 par, due 10/2034) Initial Acquisition Date 6/13/2022 Reference Rate and Spread SOFR+ 6.46% Interest Rate 11.84%2023-01-012023-12-310001508655Debt Investments Financial Services TradingScreen, Inc. First-lien loan ($50,078 par, due 4/2027) Initial Acquisition Date 4/30/2021 Reference Rate and Spread SOFR + 6.35% Interest Rate 11.66%2024-01-012024-03-310001508655Equity and Other Investments Financial Services Oxford Square Capital Corp. Common Shares (1,620 shares) Initial Acquisition Date 8/5/20152024-01-012024-03-310001508655Debt Investments, Manufacturing, ASP Unifrax Holdings, Inc, First-lien loan (EUR 1,023 par, due 12/2025) Initial Acquisition Date 9/14/2023 Reference Rate and Spread E + 3.75% Interest Rate 7.65%2024-01-012024-03-310001508655Debt Investments Financial Services BTRS Holdings, Inc. First-lien revolving loan ($2,410 par, due 12/2028) Initial Acquisition Date 12/16/2022 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.58%2024-03-310001508655Equity and Other Investments Structured Credit KKR CLO Ltd, 49A Structured Product ($1,000 par, due 7/2035) Initial Acquisition Date 6/2/2022 Reference Rate and Spread SOFR+ 8.26% Interest Rate 13.32%2024-01-012024-03-310001508655Equity and Other Investments Oil, Gas and Consumable Fuels Murchison Oil and Gas, LLC Preferred Units (13,355 units) Initial Acquisition Date 6/30/20222024-01-012024-03-310001508655tslx:SupplementalDividendMember2024-02-152024-02-150001508655Equity and Other Investments Marketing Services Validity, Inc. Series A Preferred Shares (3,840,000 shares) Initial Acquisition Date 5/31/20182023-01-012023-12-310001508655us-gaap:IncomeApproachValuationTechniqueMembertslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMemberus-gaap:MeasurementInputDiscountRateMember2023-12-310001508655Interest Rate Swap Company Receives 2.50% Company Pays SOFR + 2.17% Maturity Date 8/1/20262023-12-310001508655Debt Investments Hotel, Gaming and Leisure IRGSE Holding Corp. First-lien revolving loan ($27,622 par, due 6/2024) Initial Acquisition Date 12/21/2018 Reference Rate and Spread SOFR + 9.65% Interest Rate 15.03%2023-12-310001508655Debt Investments Internet Services Lucidworks, Inc. First-lien loan ($8,912 par, due 2/2027) Initial Acquisition Date 2/11/2022 Reference Rate and Spread SOFR + 7.50% Interest Rate 12.86% (incl. 3.50% PIK)2023-12-310001508655us-gaap:ValuationTechniqueDiscountedCashFlowMembertslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Member2023-12-310001508655tslx:DelayedDrawMembertslx:LeantaasHoldingsIncMember2023-12-310001508655Equity and Other Investments Business Services Mitnick TA Aggregator, L.P. Membership Interest (0.43% ownership) Initial Acquisition Date 5/2/20222024-01-012024-03-310001508655Debt Investments Chemicals Erling Lux Bidco SARL First-lien loan (EUR 7,239 par, due 9/2028) Initial Acquisition Date 9/6/2022 Reference Rate and Spread E + 6.75% Interest Rate 10.70%2023-12-310001508655tslx:EquityAndOtherInvestmentsMember2023-12-310001508655tslx:MezzanineDebtInvestmentsMember2023-12-310001508655Controlled Affiliated Investments IRGSE Holding Corp.2023-01-012023-12-310001508655Debt Investments Communications IntelePeer Holdings, Inc. Convertible note ($4,700 par, due 5/2028) Initial Acquisition Date 5/12/2021 Reference Rate and Spread 7.50% Interest Rate 7.50% PIK2023-12-310001508655tslx:DelayedDrawRevolverEquityMembertslx:AzuriteIntermediateHoldingsIncMember2024-03-310001508655Equity and Other Investments Internet Services SMA Technologies Holdings, LLC Class B Units (923,250 units) Initial Acquisition Date 11/21/20222024-01-012024-03-310001508655Debt Investments Financial Services TradingScreen, Inc. First-lien loan ($47,198 par, due 4/2027) Initial Acquisition Date 4/30/2021 Reference Rate and Spread SOFR + 6.35% Interest Rate 11.73%2023-12-310001508655Equity and Other Investments Education Astra 2L Holdings II LLC Membership Interest (10.17% ownership) Initial Acquisition Date 1/13/20222024-01-012024-03-310001508655Debt Investments Office Products USR Parent, Inc. ABL FILO term loan ($16,500 par, due 4/2027) Initial Acquisition Date 4/25/2022 Reference Rate and Spread SOFR + 6.50% Interest Rate 11.83%2024-03-310001508655Equity and Other Investments Education RMCF IV CIV XXXV, LP. Partnership Interest (11.94% ownership) Initial Acquisition Date 6/8/20212024-03-310001508655Controlled Affiliated Investments IRGSE Holding Corp.2023-12-310001508655Debt Investments Business Services Mitnick Corporate Purchaser, Inc First-lien loan ($328 par, due 5/2029) Initial Acquisition Date 5/2/2022 Reference Rate and Spread SOFR + 4.60% Interest Rate 9.91%2024-01-012024-03-310001508655Equity and Other Investments Structured Credit Carlyle Global Market Strategies CLO Ltd, Series 2016-1, Ltd Structured Product ($1,600par,due4/2034) Initial Acquisition Date 2/15/2023 Reference Rate and Spread SOFR+6.86% Interest Rate 12.18%2024-01-012024-03-310001508655us-gaap:CommonStockMember2023-01-012023-03-310001508655tslx:TwoThousandTwentyFourNotesMemberus-gaap:InterestRateSwapMember2023-01-012023-03-310001508655Debt Investments Human Resource Support Services Elysian Finco Ltd. First-lien loan ($19,519 par, due 1/2028) Initial Acquisition Date 1/31/2021 Reference Rate and Spread SOFR + 6.65% Interest Rate 2.03% (incl. 6.50% PIK)2023-01-012023-12-310001508655Debt Investments Automotive Bestpass, Inc. First-lien loan ($44,800 par, due 5/2029) Initial Acquisition Date 5/26/2023 Reference Rate and Spread SOFR + 5.75% Interest Rate 11.11%2023-12-310001508655Debt Investments Internet Services Coupa Holdings, LLC First-lien loan ($43,191 par, due 2/2030) Initial Acquisition Date 2/27/2023 Reference Rate and Spread SOFR + 7.50% Interest Rate 12.81%2024-03-310001508655Debt Investments Manufacturing Heritage Environmental Services, Inc. First-lien loan ($12,346 par, due 1/2031) Initial Acquisition Date 1/31/2024 Reference Rate and Spread SOFR + 5.50% Interest Rate 10.81%2024-01-012024-03-310001508655Equity and Other Investments Education2024-03-310001508655Debt Investments Business Services Crewline Buyer, Inc. First-lien loan ($56,324 par, due 11/2030) Initial Acquisition Date 11/8/2023 Reference Rate and Spread SOFR + 6.75% Interest Rate 12.06%2024-01-012024-03-310001508655Equity and Other Investments Oil, Gas and Consumable Fuels2023-12-310001508655us-gaap:OverAllotmentOptionMember2023-06-120001508655Equity and Other Investments Business Services Sprinklr, Inc. Common Shares (283,499 shares) Initial Acquisition Date 6/24/20212024-03-310001508655us-gaap:FairValueInputsLevel1Member2024-03-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. Series C Preferred Shares (1,915,114 shares) Initial Acquisition Date 10/13/20202024-01-012024-03-310001508655Equity and Other Investments Structured Credit MidOcean Credit CLO Ltd, Series 2016-6A Structured Product ($3,500 par, due 4/2033) Initial Acquisition Date 5/23/2022 Reference Rate and Spread SOFR+ 3.78% Interest Rate 9.20%2023-12-310001508655tslx:MezzanineDebtInvestmentsMember2023-01-012023-12-310001508655Interest Rate Swap Company Receives 3.875% Company SOFR + 2.51% Maturity Date 11/1/20242023-01-012023-12-310001508655Debt Investments Other Omnigo Software, LLC First-lien loan ($39,840 par, due 3/2026) Initial Acquisition Date 3/31/2021 Reference Rate and Spread SOFR + 6.60% Interest Rate 11.93%2024-03-310001508655Debt Investments Retail and Consumer Products Rapid Data GmbH Unternehmensberatung, First-lien loan (EUR 4,495 par, due 7/2029), Initial Acquisition Date 7/11/2023 Reference Rate and Spread E + 6.50% Interest Rate 10.43%2024-01-012024-03-310001508655Debt Investments Retail and Consumer Products Bed Bath and Beyond Inc. Super-Priority DIP term loan ($4,739 par, due 9/2024) Initial Acquisition Date 4/24/2023 Reference Rate and Spread SOFR + 7.90% Interest Rate 13.26%2023-01-012023-12-310001508655tslx:MezzanineDebtInvestmentsMember2024-01-012024-03-310001508655Debt Investments Retail and Consumer Products American Achievement, Corp. Subordinated note ($4,740 par, due 9/2026) Initial Acquisition Date 3/16/2021 Reference Rate and Spread SOFR + 1.15% Interest Rate 6.54% PIK2023-12-3100015086552024-01-012024-03-310001508655us-gaap:FairValueInputsLevel2Member2023-12-310001508655tslx:ManufacturingMember2023-12-310001508655Controlled Affiliated Investments IRGSE Holding Corp.2022-12-310001508655Equity and Other Investments Human Resource Support Services bswift, LLC Class A-1 Units (2,393,509 units) Initial Acquisition Date 11/7/20222023-01-012023-12-310001508655Debt Investments Retail and Consumer Products 99 Cents Only Stores LLC ABL FILO term loan ($25,000 par, due 5/2025) Initial Acquisition Date 9/6/2017 Reference Rate and Spread SOFR + 8.65% Interest Rate 13.97%2024-01-012024-03-310001508655Debt Investments Business Services ForeScout Technologies, Inc. First-lien loan ($5,476 par, due 8/2026) Initial Acquisition Date 7/1/2022 Reference Rate and Spread SOFR + 8.10% Interest Rate 13.45%2023-12-310001508655Equity and Other Investments Hotel, Gaming and Leisure IRGSE Holding Corp. Class A Units (33,790,171 units) Initial Acquisition Date 12/21/20182023-01-012023-12-310001508655Equity and Other Investments Internet Services Bayshore Intermediate #2, L.P. Co-Invest 2 Common Units (3,493,701 units) Initial Acquisition Date 10/1/20212023-01-012023-12-310001508655Debt Investments Education Destiny Solutions Parent Holding Company First-lien loan ($59,400 par, due 6/2026) Initial Acquisition Date 6/8/2021 Reference Rate and Spread SOFR + 5.85% Interest Rate 11.18%2024-01-012024-03-310001508655Debt Investments Retail and Consumer Products Rapid Data GmbH Unternehmensberatung First-lien loan (EUR 4,495 par, due 7/2029) Initial Acquisition Date 7/11/2023 Reference Rate and Spread E + 6.50% Interest Rate 10.48%2023-01-012023-12-3100015086552024-03-310001508655tslx:DelayedDrawMembertslx:SlBuyerCorpMember2023-12-310001508655Debt Investments Internet Services Higher Logic, LLC First-lien loan ($52,937 par, due 1/2025) Initial Acquisition Date 6/18/2018 Reference Rate and Spread SOFR + 6.75% Interest Rate 12.10%2023-01-012023-12-310001508655srt:MaximumMemberus-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:SecondLienDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMember2023-12-310001508655Debt Investments Business Services Mitnick Corporate Purchaser, Inc First-lien loan ($328 par, due 5/2029) Initial Acquisition Date 5/2/2022 Reference Rate and Spread SOFR + 4.60% Interest Rate 9.91%2024-03-310001508655us-gaap:IncomeApproachValuationTechniqueMembertslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputDiscountRateMember2024-03-310001508655tslx:RevolverMembertslx:EMSLinqIncMember2023-12-310001508655Debt Investments Human Resource Support Services Elysian Finco Ltd. First-lien loan ($19,519 par, due 1/2028) Initial Acquisition Date 1/31/2021 Reference Rate and Spread SOFR + 6.65% Interest Rate 2.03% (incl. 6.50% PIK)2023-12-310001508655Debt Investments Manufacturing Skylark UK DebtCo Limited First-lien loan (GBP 16,640 par, due 9/2030) Initial Acquisition Date 9/7/2023 Reference Rate and Spread S + 6.25% Interest Rate 11.52%2023-01-012023-12-310001508655Debt Investments Internet Services CrunchTime Information, Systems, Inc. First-lien loan ($59,500 par, due 6/2028) Initial Acquisition Date 6/17/2022 Reference Rate and Spread SOFR + 6.00% Interest Rate 11.36%2023-01-012023-12-310001508655Equity and Other Investments Structured Credit Octagon Investment Partners 18 Ltd, Series 2018 – 18A Structured Product ($1,000 par, due 4/2031) Initial Acquisition Date 7/26/2022 Reference Rate and Spread SOFR+ 2.96% Interest Rate 8.28%2024-01-012024-03-310001508655tslx:SecondLienDebtInvestmentsMember2022-12-310001508655tslx:EquityAndOtherInvestmentsMember2023-12-310001508655Equity and Other Investments Oil, Gas and Consumable Fuels Murchison Oil and Gas, LLC 13,355 Preferred Units Initial Acquisition Date 6/30/20222023-12-310001508655Equity and Other Investments Structured Credit Bain Capital Credit CLO Ltd, Series 2018-1A Structured Product ($500par,due4/2031) Initial Acquisition Date 10/15/2020 Reference Rate and Spread SOFR+5.61% Interest Rate 10.93%2024-03-310001508655us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InterestRateSwapMember2023-01-012023-03-310001508655tslx:SupplementalDividendMember2024-02-150001508655Debt Investments, Manufacturing, ASP Unifrax Holdings, Inc, First lien loan ($1,127 par, due 12/2025) Initial Acquisition Date 8/25/2023 Reference Rate and Spread SOFR + 3.90% Interest Rate 9.20%2024-03-310001508655tslx:BaseDividendMember2023-02-162023-02-160001508655Debt Investments Business Services Information Clearinghouse, LLC and MS Market Service, LLC First-lien loan ($17,595 par, due 12/2026) Initial Acquisition Date 12/20/2021 Reference Rate and Spread SOFR + 6.65% Interest Rate 11.98%2024-03-310001508655Debt Investments Healthcare Homecare Software Solutions, LLC First-lien loan ($65,000 par, due 10/2026) Initial Acquisition Date 10/6/2021 Reference Rate and Spread SOFR + 5.70% Interest Rate 11.13%2024-03-310001508655Equity and Other Investments Business Services Artisan Topco LP Class A Preferred Units (2,117,264 units) Initial Acquisition Date 11/7/20232023-01-012023-12-310001508655tslx:DelayedDrawMembertslx:BearOpCoLLCMember2023-12-310001508655Equity and Other Investments Healthcare Merative Topco L.P. 989,691 Class A-1 Units Initial Acquisition Date 6/30/20222023-01-012023-12-310001508655Debt Investments Retail and Consumer Products Bed Bath and Beyond Inc. Super-Priority DIP term loan ($4,550 par, due 9/2024) Initial Acquisition Date 4/24/2023 Reference Rate and Spread SOFR + 7.90% Interest Rate 13.23%2024-01-012024-03-310001508655Debt Investments Hotel, Gaming and Leisure IRGSE Holding Corp. First-lien revolving loan ($30,102 par, due 6/2024) Initial Acquisition Date 12/21/2018 Reference Rate and Spread SOFR + 9.65% Interest Rate 14.96%2024-01-012024-03-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. 569,991 Warrants Initial Acquisition Date 4/2/20202024-01-012024-03-310001508655Debt Investments Internet Services CrunchTime Information, Systems, Inc. First-lien loan ($59,350 par, due 6/2028) Initial Acquisition Date 6/17/2022 Reference Rate and Spread SOFR + 6.00% Interest Rate 11.33%2024-01-012024-03-310001508655Equity and Other Investments Financial Services AF Eagle Parent, L.P. Partnership (121,329 units) Initial Acquisition Date 11/27/20232023-01-012023-12-310001508655Equity and Other Investments Oil, Gas and Consumable Fuels TRP Assets, LLC Partnership Interest (1.89% ownership) Initial Acquisition Date 8/25/20222023-12-310001508655Equity and Other Investments Internet Services2023-12-310001508655Debt Investments Human Resource Support Services HireVue, Inc. First-lien revolving loan ($1,377 par, due 5/2029) Initial Acquisition Date 5/3/2023 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.56%2024-01-012024-03-310001508655Debt Investments Communications Banyan Software Holdings, LLC First-lien loan ($35,449 par, due 10/2026) Initial Acquisition Date 1/7/2023 Reference Rate and Spread SOFR + 7.35% Interest Rate 12.68%2024-01-012024-03-310001508655Debt Investments Hotel, Gaming and Leisure IRGSE Holding Corp. First-lien loan ($30,261 par, due 6/2024) Initial Acquisition Date 12/21/2018 Reference Rate and Spread SOFR + 9.65% Interest Rate 15.00%2023-01-012023-12-310001508655Equity and Other Investments Communications2023-12-310001508655tslx:TwentyTwentyNineNotesMember2024-01-082024-01-080001508655Equity and Other Investments Healthcare Merative Topco L.P. 989,691 Class A-1 Units Initial Acquisition Date 6/30/20222023-12-310001508655Interest Rate Swap Company Pays SOFR + 2.99% Maturity Date 8/14/20282024-03-310001508655tslx:ChemicalsMember2023-12-310001508655Debt Investments Financial Services Passport Labs, Inc. Convertible Promissory Note A ($1,086 par, due 8/2026) Initial Acquisition Date 3/2/2023 Reference Rate and Spread 8.00% Interest Rate 8.00%2024-03-310001508655Equity and Other Investments Structured Credit Madison Park CLO, Series 2018-28A Structured Product ($1,000 par, due 7/2030) Initial Acquisition Date 6/28/2022 Reference Rate and Spread SOFR+ 5.51% Interest Rate 10.91%2023-01-012023-12-310001508655us-gaap:CommonStockMember2024-01-012024-03-310001508655Debt Investments Financial Services Kyriba Corp. First-lien loan ($36,399 par, due 4/2028) Initial Acquisition Date 12/21/2023 Reference Rate and Spread SOFR + 8.50% Interest Rate 13.83% (incl. 8.50% PIK)2024-01-012024-03-310001508655Debt Investments Manufacturing2024-03-310001508655Equity and Other Investments Structured Credit CarVal CLO III Ltd, Series 2019-2A Structured Product ($1,000par,due7/2032) Initial Acquisition Date 6/30/2022 Reference Rate and Spread SOFR+6.70% Interest Rate 12.11%2023-01-012023-12-310001508655Debt Investments Healthcare SL Buyer Corp. First-lien loan ($31,875 par, due 7/2029) Initial Acquisition Date 7/7/2023 Reference Rate and Spread SOFR + 7.75% Interest Rate 13.08%2024-03-310001508655Debt Investments Healthcare Raptor US Buyer II Corp. First-lien loan ($15,530 par,due3/2029) Initial Acquisition Date 3/24/2023 Reference Rate and Spread SOFR + 6.75% Interest Rate 12.06%2024-03-310001508655Equity and Other Investments Structured Credit2023-12-310001508655Debt Investments Business Services Galileo Parent, Inc. First-lien loan ($64,579 par, due 5/2030) Initial Acquisition Date 5/3/2023 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.56%2024-03-310001508655Equity and Other Investments Internet Services SMA Technologies Holdings, LLC Class B Units (923,250 shares) Initial Acquisition Date 11/21/20222023-12-310001508655us-gaap:RetainedEarningsMember2024-01-012024-03-310001508655tslx:TwoThousandTwentyNineNotesMember2024-03-310001508655tslx:DelayedDrawMembertslx:LaramieEnergyLLCMember2023-12-310001508655Debt Investments Human Resource Support Services PageUp People, Ltd. First-lien loan (GBP 3,104 par, due 12/2025) Initial Acquisition Date 10/28/2021 Reference Rate and Spread S + 5.03% Interest Rate 10.22%2023-12-310001508655us-gaap:DomesticCountryMember2023-12-310001508655Equity and Other Investments Structured Credit Gulf Stream Meridian, Series 2021-4A Structured Product ($1,015par,due7/2034) Initial Acquisition Date 6/3/2022 Reference Rate and Spread SOFR+6.61% Interest Rate 11.93%2024-01-012024-03-310001508655Debt Investments Business Services Dye & Durham Corp. First-lien loan (CAD 37,874 par, due 12/2027) Initial Acquisition Date 12/3/2021 Reference Rate and Spread C + 5.75% Interest Rate 11.20%2023-12-310001508655us-gaap:RevolvingCreditFacilityMembersrt:MinimumMember2024-04-240001508655Equity and Other Investments Structured Credit Pikes Peak CLO, Series 2021-9A Structured Product ($2,000 par,due 10/2034) Initial Acquisition Date 8/31/2022 Reference Rate and Spread SOFR+ 6.84% Interest Rate 12.23%2023-01-012023-12-310001508655tslx:AlaskaBidcoOyMembertslx:DelayedDrawAndRevolverMember2023-12-310001508655Equity and Other Investments Structured Credit Benefit Street Partners CLO Ltd, Series 2015-BR Structured Product ($2,500par,due7/2034) Initial Acquisition Date 7/13/2022 Reference Rate and Spread SOFR+4.11% Interest Rate 9.53%2023-12-310001508655Debt Investments Communications IntelePeer Holdings, Inc. Convertible note ($4,790 par, due 5/2028) Initial Acquisition Date 5/12/2021 Reference Rate and Spread 7.50% Interest Rate 7.50% PIK2024-01-012024-03-3100015086552015-08-040001508655Debt Investments Human Resource Support Services2024-03-310001508655Equity and Other Investments Business Services Dye & Durham, Ltd. Common Shares (126,968 shares) Initial Acquisition Date 12/3/20212023-12-310001508655Debt Investments Financial Services Volante Technologies, Inc. First-lien loan ($2,712 par, due 9/2028) Initial Acquisition Date 9/29/2023 Reference Rate and Spread 16.50% Interest Rate 16.50% PIK2024-01-012024-03-310001508655tslx:AssetValuationWaterfallMemberus-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMember2023-12-310001508655Equity and Other Investments Structured Credit Cedar Funding CLO Ltd, Series 2018-7A Structured Product ($1,000par,due1/2031) Initial Acquisition Date 7/21/2022 Reference Rate and Spread SOFR+4.81% Interest Rate 10.23%2023-01-012023-12-310001508655Equity and Other Investments Retail and Consumer Products Copper Bidco, LLC Trust Certificates (996,958 Certificates) Initial Acquisition Date 1/30/20212023-01-012023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:MarcuraEquitiesLtdMember2024-03-310001508655tslx:RevolverMembertslx:WranglerTopcoLlcMember2023-12-310001508655Debt Investments Financial Services BCTO Bluebill Buyer, Inc. First-lien loan ($28,640 par, due 7/2029) Initial Acquisition Date 7/20/2023 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.60%2023-01-012023-12-310001508655Equity and Other Investments Human Resource Support Services DaySmart Holdings, LLC Class A Units (166,811 units) Initial Acquisition Date 12/18/20202024-03-310001508655Equity and Other Investments Oil, Gas and Consumable Fuels TRP Assets, LLC Partnership Interest (1.89% ownership) Initial Acquisition Date 8/25/20222024-03-310001508655Debt Investments Transportation2024-03-310001508655Interest Rate Swap Company Receives 6.125% Company Pays SOFR + 2.44% Maturity Date 3/1/20292024-03-310001508655tslx:DelayedDrawAndRevolverMembertslx:HornetsecurityHoldingGmbhMember2024-03-310001508655Interest Rate Swap Company Receives 2.50% Company Pays SOFR + 2.17% Maturity Date 8/1/20262024-01-012024-03-310001508655tslx:TwoThousandTwentyNineNotesMember2024-01-080001508655Debt Investments Healthcare Raptor US Buyer II Corp. First-lien loan ($15,569 par, due 3/2029) Initial Acquisition Date 3/24/2023 Reference Rate and Spread SOFR + 6.75% Interest Rate 12.10%2023-01-012023-12-310001508655Debt Investments Communications Banyan Software Holdings, LLC First-lien loan ($35,449 par, due 10/2026) Initial Acquisition Date 1/7/2023 Reference Rate and Spread SOFR + 7.35% Interest Rate 12.68%2024-03-310001508655tslx:PrimeRevenueIncMembertslx:RevolverMember2023-12-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. 569,991 Warrants Initial Acquisition Date 4/2/20202023-12-310001508655tslx:CapitalGainsAccrueFollowingMarchThirtyFirstTwoThousandFourteenMembertslx:InvestmentAdvisoryAgreementMember2011-04-152011-04-150001508655us-gaap:RevolvingCreditFacilityMember2024-03-310001508655tslx:FirstLienDebtInvestmentsMember2023-12-310001508655tslx:StructuredCreditInvestmentsMember2023-12-310001508655tslx:AmericanAchievementCorpMembertslx:RevolverMember2023-12-310001508655Equity and Other Investments Structured Credit Bain Capital Credit CLO Ltd, Series 2018-1A Structured Product ($500par,due4/2031) Initial Acquisition Date 10/15/2020 Reference Rate and Spread SOFR+5.61% Interest Rate 10.93%2024-01-012024-03-310001508655Equity and Other Investments Financial Services CLGF Holdco 2, LLC 334,682 Warrants Initial Acquisition Date 11/7/20232023-01-012023-12-310001508655tslx:TwoThousandTwentyFourNotesMember2023-12-310001508655Equity and Other Investments Structured Credit CIFC CLO Ltd, Series 2018-3A Structured Product ($1,000par,due7/2031)Initial Acquisition Date 6/16/2022 Reference Rate and Spread SOFR+5.76% Interest Rate 11.16%2023-12-310001508655Debt Investments Human Resource Support Services PayScale Holdings, Inc. First-lien loan ($71,196 par, due 5/2027) Initial Acquisition Date 5/3/2019 Reference Rate and Spread SOFR + 6.35% Interest Rate 11.70%2023-12-310001508655Equity and Other Investments Financial Services2024-03-310001508655Equity and Other Investments Structured Credit Voya CLO Ltd, Series 2018-3A Structured Product ($2,750 par, due 10/2031) Initial Acquisition Date 6/22/2022 Reference Rate and Spread SOFR+ 6.01% Interest Rate 11.41%2023-01-012023-12-310001508655Debt Investments Internet Services Piano Software, Inc. First-lien loan ($52,048 par, due 2/2026) Initial Acquisition Date 2/25/2021 Reference Rate and Spread SOFR + 7.85% Interest Rate 13.18% (incl.1.94% PIK)2024-01-012024-03-310001508655Equity and Other Investments Financial Services TradingScreen, Inc. Class A Units (600,000 units) Initial Acquisition Date 5/14/20212023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:ErlingLuxBidcoSarlMember2023-12-310001508655Equity and Other Investments Healthcare Raptor US Buyer II Corp. 20,268 Ordinary Shares Initial Acquisition Date 3/24/20232024-01-012024-03-310001508655Equity and Other Investments Structured Credit Park Avenue Institutional Advisers CLO Ltd, Series 2018-1A Structured Product ($1,000 par,due 10/2031) Initial Acquisition Date 9/23/2022 Reference Rate and Spread SOFR+ 3.59% Interest Rate 9.01%2023-01-012023-12-310001508655Equity and Other Investments Structured Credit American Money Management Corp CLO Ltd, Series 2016-18A Structured Product ($1,500 par,due 5/2031) Initial Acquisition Date 6/22/2022 Reference Rate and Spread SOFR+3.31% Interest Rate 8.70%2023-01-012023-12-310001508655tslx:FirstLienDebtInvestmentsMembertslx:AssetValuationWaterfallMemberus-gaap:FairValueInputsLevel3Member2024-03-310001508655Debt Investments Business Services Price Fx Inc. First-lien loan (EUR 910 par, due 10/2029) Initial Acquisition Date 10/27/2023 Reference Rate and Spread E + 7.00% Interest Rate 10.93%2024-03-310001508655Equity and Other Investments Financial Services TradingScreen, Inc. Class A Units (600,000 units) Initial Acquisition Date 5/14/20212023-01-012023-12-310001508655us-gaap:SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMembertslx:TwoThousandTwentyNineNotesMember2024-01-012024-03-310001508655Equity and Other Investments Business Services Artisan Topco LP Class A Preferred Units (2,117,264 units) Initial Acquisition Date 11/7/20232023-12-310001508655Equity and Other Investments Business Services ReliaQuest, LLC 90,634 Warrants Initial Acquisition Date 12/20/20232023-01-012023-12-310001508655Equity and Other Investments Business Services ReliaQuest, LLC Series A Preferred Stock (1,748 units) Initial Acquisition Date 12/20/2023 Reference Rate and Spread SOFR+12.00% Interest Rate 17.37% PIK2024-01-012024-03-310001508655Debt Investments Internet Services2024-03-310001508655Equity and Other Investments Structured Credit Cedar Funding CLO Ltd, Series 2018-7A Structured Product ($1,000par,due1/2031) Initial Acquisition Date 7/21/2022 Reference Rate and Spread SOFR+4.81% Interest Rate 10.13%2024-03-310001508655us-gaap:InterestRateSwapMembertslx:TwoThousandTwentyNineNotesMember2024-01-012024-03-310001508655Debt Investments Human Resource Support Services HireVue, Inc. First-lien revolving loan ($1,377 par, due 5/2029) Initial Acquisition Date 5/3/2023 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.56%2024-03-310001508655Equity and Other Investments Internet Services SMA Technologies Holdings, LLC Class A Units (1,300 units) Initial Acquisition Date 11/21/20222024-03-310001508655Debt Investments Retail and Consumer Products PDI TA Holdings, Inc. First-lien loan ($14,410 par, due 2/2031) Initial Acquisition Date 2/1/2024 Reference Rate and Spread SOFR +5.50% Interest Rate 10.83%2024-03-310001508655tslx:ChemicalsMember2024-03-310001508655Debt Investments Business Services Galileo Parent, Inc. First-lien revolving loan ($3,317 par, due 5/2029) Initial Acquisition Date 5/3/2023 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.60%2023-12-310001508655Debt Investments Automotive Bestpass, Inc. First-lien loan ($44,688 par, due 5/2029) Initial Acquisition Date 5/26/2023 Reference Rate and Spread SOFR + 5.75% Interest Rate 11.08%2024-01-012024-03-310001508655tslx:NonControlledNonAffiliatedInvestmentsMember2023-01-012023-03-310001508655tslx:InvestmentAdvisoryAgreementMember2011-04-152011-04-150001508655Debt Investments Financial Services BTRS Holdings, Inc. First-lien loan ($47,051 par, due 12/2028) Initial Acquisition Date 12/16/2022 Reference Rate and Spread SOFR + 8.00% Interest Rate 13.38%2023-12-310001508655tslx:DelayedDrawMembertslx:LucidworksIncMember2023-12-310001508655Debt Investments Business Services Acceo Solutions, Inc. First-lien loan (CAD 52,941 par, due 10/2025) Initial Acquisition Date 7/6/2018 Reference Rate and Spread C + 4.75% Interest Rate 10.21%2023-01-012023-12-310001508655tslx:OilGasAndConsumableFuelsMember2023-12-310001508655us-gaap:NondesignatedMemberus-gaap:InterestRateSwapMember2024-01-012024-03-310001508655us-gaap:RevolvingCreditFacilityMember2024-04-242024-04-240001508655Equity and Other Investments Structured Credit KKR CLO Ltd, 49A Structured Product ($1,000 par, due 7/2035) Initial Acquisition Date 6/2/2022 Reference Rate and Spread SOFR+ 8.26% Interest Rate 13.32%2024-03-310001508655Interest Rate Swap Company Receives 3.875% Company SOFR + 2.51% Maturity Date 11/1/20242024-03-310001508655tslx:SecondLienDebtInvestmentsMember2023-01-012023-12-310001508655us-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:SecondLienDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMembersrt:WeightedAverageMember2024-03-310001508655Interest Rate Swap Company Receives 2.50% Company Pays SOFR + 2.17% Maturity Date 8/1/20262024-03-310001508655Hedge Accounting Swaps2023-01-012023-12-310001508655Equity and Other Investments Structured Credit Eaton CLO Ltd, Series 2020-1A Structured Product ($1,000par,due10/2034) Initial Acquisition Date 8/11/2022 Reference Rate and Spread SOFR+6.51% Interest Rate 11.83%2024-01-012024-03-310001508655Debt Investments Oil, Gas and Consumable Fuels TRP Assets, LLC First-lien loan ($65,000 par, due 12/2025) Initial Acquisition Date 12/3/2021 Reference Rate and Spread SOFR + 7.76% Interest Rate 13.11%2023-01-012023-12-310001508655Equity and Other Investments Business Services ReliaQuest, LLC 90,634 Warrants Initial Acquisition Date 12/20/20232023-12-310001508655Equity and Other Investments Business Services ReliaQuest, LLC Class A-1 Units (637,713 units) Initial Acquisition Date 11/23/20212023-01-012023-12-310001508655Debt Investments Oil, Gas and Consumable Fuels2024-03-310001508655Debt Investments Communications IntelePeer Holdings, Inc. First-lien loan ($33,646 par, due 12/2024) Initial Acquisition Date 12/2/2019 Reference Rate and Spread SOFR + 8.40% Interest Rate 13.75%2023-12-310001508655tslx:TwoThousandTwentyThreeTwentyFourTwentySixTwentyeightAndTwentyNineNotesMember2023-01-012023-03-310001508655tslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Member2023-01-012023-03-310001508655us-gaap:RetainedEarningsMember2023-03-310001508655Debt Investments Internet Services Piano Software, Inc. First-lien loan ($50,889 par, due 2/2026) Initial Acquisition Date 2/25/2021 Reference Rate and Spread SOFR + 7.10% Interest Rate 12.45%2023-12-310001508655Debt Investments, Manufacturing, ASP Unifrax Holdings, Inc, First lien loan ($1,127 par, due 12/2025) Initial Acquisition Date 8/25/2023 Reference Rate and Spread SOFR + 3.90% Interest Rate 9.20%2024-01-012024-03-310001508655Interest Rate Swap Company Receives 6.95% Company Pays SOFR + 2.99% Maturity Date 8/14/20282024-01-012024-03-310001508655tslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Member2023-12-310001508655tslx:InvestmentAdvisoryAgreementMember2023-01-012023-03-310001508655Equity and Other Investments Internet Services Lucidworks, Inc. Series F Preferred Shares (199,054 shares) Initial Acquisition Date 8/2/20192023-01-012023-12-310001508655Debt Investments Human Resource Support Services PageUp People, Ltd. First-lien loan (AUD 11,938 par, due 12/2025) Initial Acquisition Date 1/11/2018 Reference Rate and Spread B + 5.00% Interest Rate 9.35%2024-03-310001508655Debt Investments Office Products USR Parent, Inc. ABL FILO term loan ($17,000 par, due 4/2027) Initial Acquisition Date 4/25/2022 Reference Rate and Spread SOFR + 6.50% Interest Rate 11.84%2023-01-012023-12-310001508655Debt Investments Chemicals Erling Lux Bidco SARL First-lien loan (EUR 7,239 par, due 9/2028) Initial Acquisition Date 9/6/2022 Reference Rate and Spread E + 6.75% Interest Rate 10.64%2024-03-310001508655Debt Investments Internet Services Bayshore Intermediate #2, L.P. First-lien revolving loan ($320 par, due 10/2027) Initial Acquisition Date 10/1/2021 Reference Rate and Spread SOFR + 6.85% Interest Rate 12.17%2024-01-012024-03-310001508655Debt Investments Transportation Marcura Equities LTD First-lien loan ($32,007 par, due 8/2029) Initial Acquisition Date 8/11/2023 Reference Rate and Spread SOFR + 7.00% Interest Rate 12.18%2024-03-310001508655Debt Investments Financial Services Ping Identity Holding Corp. First-lien loan ($22,727 par, due 10/2029) Initial Acquisition Date 10/17/2022 Reference Rate and Spread SOFR + 7.00% Interest Rate 12.33%2024-03-310001508655tslx:AdviserMemberus-gaap:GeneralAndAdministrativeExpenseMembertslx:AdministrationAgreementMember2023-01-012023-03-310001508655us-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:SecondLienDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMembersrt:WeightedAverageMember2023-12-310001508655us-gaap:AdditionalPaidInCapitalMember2023-03-310001508655Equity and Other Investments Structured Credit Carlyle Global Market Strategies CLO Ltd, Series 2014-4RA Structured Product ($1,000par,due7/2030) Initial Acquisition Date 5/26/2022 Reference Rate and Spread SOFR+3.16% Interest Rate 8.56%2023-01-012023-12-310001508655Debt Investments Transportation Marcura Equities LTD First-lien loan ($32,007 par, due 8/2029) Initial Acquisition Date 8/11/2023 Reference Rate and Spread SOFR + 7.00% Interest Rate 12.18%2024-01-012024-03-310001508655Equity and Other Investments Business Services Artisan Topco LP Class A Preferred Units (2,117,264 units) Initial Acquisition Date 11/7/20232024-03-310001508655Equity and Other Investments Internet Services Bayshore Intermediate #2, L.P. Co-Invest 2 Common Units (3,493,701 units) Initial Acquisition Date 10/1/20212024-03-310001508655Debt Investments Financial Services Fullsteam Operations LLC First-lien loan ($33,479 par, due 11/2029) Initial Acquisition Date 11/27/2023 Reference Rate and Spread SOFR + 8.40% Interest Rate 13.73%2024-03-310001508655Debt Investments Human Resource Support Services Elysian Finco Ltd. First-lien loan ($20,087 par, due 1/2028) Initial Acquisition Date 1/31/2021 Reference Rate and Spread SOFR + 6.65% Interest Rate 12.03% (incl. 6.50% PIK)2024-03-310001508655Debt Investments Healthcare BCTO Ace Purchaser, Inc. Second-lien loan ($5,854 par, due 1/2030) Initial Acquisition Date 1/23/2023 Reference Rate and Spread SOFR + 10.70% Interest Rate 16.02% PIK2024-01-012024-03-310001508655Equity and Other Investments Structured Credit Crown Point CLO Ltd, Series 2021-10A Structured Product ($1,000par,due7/2034) Initial Acquisition Date 6/14/2022 Reference Rate and Spread SOFR+7.11% Interest Rate 12.53%2023-01-012023-12-310001508655tslx:RevolverMembertslx:BayshoreIntermediate2LPMember2023-12-310001508655Debt Investments Education Destiny Solutions Parent Holding Company First-lien loan ($59,550 par, due 6/2026) Initial Acquisition Date 6/8/2021 Reference Rate and Spread SOFR + 5.85% Interest Rate 11.21%2023-12-310001508655Debt Investments Human Resource Support Services PrimePay Intermediate, LLC First-lien loan ($34,287 par, due 12/2026) Initial Acquisition Date 12/17/2021 Reference Rate and Spread SOFR + 7.15% Interest Rate 12.46%2024-03-310001508655tslx:DelayedDrawMembertslx:BanyanSoftwareHoldingsLlcMember2023-12-310001508655Equity and Other Investments Financial Services Passport Labs, Inc. 17,534 Warrants Initial Acquisition Date 4/28/20212024-03-310001508655Debt Investments Financial Services Kyriba Corp. First-lien loan (EUR 11,158 par, due 4/2028) Initial Acquisition Date 12/21/2023 Reference Rate and Spread E + 8.50% Interest Rate 12.44 (incl. 8.50% PIK)2024-03-310001508655tslx:FirstLienDebtInvestmentsMember2023-12-310001508655tslx:DelayedDrawMembertslx:Project44IncMember2024-03-310001508655country:NL2023-12-310001508655Debt Investments Manufacturing ASP Unifrax Holdings, Inc. Unsecured Note ($1,059 par, due 9/2029) Initial Acquisition Date 8/31/2023 Reference Rate and Spread 7.50% Interest Rate 7.50%2023-01-012023-12-310001508655Equity and Other Investments Automotive Clarience Technologies, LLC Class A Units (333 Units) Initial Acquisition Date 2/12/20242024-01-012024-03-310001508655Equity and Other Investments Financial Services Newport Parent Holdings, L.P. Class A-2 Units (131,569 units) Initial Acquisition Date 12/10/20202023-01-012023-12-310001508655Equity and Other Investments Business Services ReliaQuest, LLC Class A-3 Units (16,957 units) Initial Acquisition Date 11/10/20232024-03-310001508655Debt Investments Human Resource Support Services PayScale Holdings, Inc. First-lien loan ($71,014 par, due 5/2027) Initial Acquisition Date 5/3/2019 Reference Rate and Spread SOFR + 6.35% Interest Rate 11.58%2024-01-012024-03-310001508655Equity and Other Investments Communications Celtra Technologies, Inc. Class A Units (1,250,000 units) Initial Acquisition Date 11/19/20212023-12-310001508655Equity and Other Investments Hotel, Gaming and Leisure IRGSE Holding Corp. Class C-1 Units (8,800,000 units) Initial Acquisition Date 12/21/20182023-01-012023-12-310001508655Debt Investments2023-12-310001508655Debt Investments Hotel, Gaming and Leisure IRGSE Holding Corp. First-lien loan ($30,261 par, due 6/2024) Initial Acquisition Date 12/21/2018 Reference Rate and Spread SOFR + 9.65% Interest Rate 14.96%2024-01-012024-03-310001508655tslx:NortheastMember2024-03-310001508655Debt Investments Internet Services Lucidworks, Inc. First-lien loan ($9,059 par, due 2/2027) Initial Acquisition Date 2/11/2022 Reference Rate and Spread SOFR + 7.50% Interest Rate 12.83% (incl. 3.50% PIK)2024-01-012024-03-3100015086552015-08-042015-08-040001508655Debt Investments Internet Services CrunchTime Information, Systems, Inc. First-lien loan ($59,500 par, due 6/2028) Initial Acquisition Date 6/17/2022 Reference Rate and Spread SOFR + 6.00% Interest Rate 11.36%2023-12-310001508655tslx:SecondLienDebtInvestmentsMember2024-03-310001508655Debt Investments Business Services Artisan Bidco, Inc First-lien loan ($38,015 par, due 11/2029) Initial Acquisition Date 11/7/2023 Reference Rate and Spread SOFR + 7.00% Interest Rate 12.32%2024-03-310001508655Debt Investments Chemicals Erling Lux Bidco SARL First-lien loan (GBP 12,287 par, due 9/2028) Initial Acquisition Date 9/6/2022 Reference Rate and Spread S + 6.75% Interest Rate 11.98%2023-01-012023-12-310001508655Debt Investments Education EMS Linq, Inc. First-lien loan ($56,216 par, due 12/2027) Initial Acquisition Date 12/22/2021 Reference Rate and Spread SOFR + 6.35% Interest Rate 11.71%2023-01-012023-12-310001508655country:GB2023-12-310001508655us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InterestRateSwapMember2024-01-012024-03-310001508655Debt Investments Internet Services Bayshore Intermediate #2, L.P. First-lien revolving loan ($480 par, due 10/2027) Initial Acquisition Date 10/1/2021 Reference Rate and Spread SOFR + 6.60% Interest Rate 12.01%2023-01-012023-12-310001508655Equity and Other Investments Business Services Sprinklr, Inc. Common Shares (283,499 shares) Initial Acquisition Date 6/24/20212024-01-012024-03-310001508655Equity and Other Investments Structured Credit Dryden Senior Loan Fund, Series 2018-55A Structured Product ($1,000par,due4/2031)Initial Acquisition Date 7/25/2022 Reference Rate and Spread SOFR+3.11% Interest Rate 8.43%2024-01-012024-03-310001508655Debt Investments Education2023-12-310001508655Debt Investments Business Services Wrangler TopCo, LLC First-lien loan ($4,153 par, due 7/2029) Initial Acquisition Date 7/7/2023 Reference Rate and Spread SOFR + 7.50% Interest Rate 12.82%2024-03-310001508655us-gaap:FairValueInputsLevel3Member2024-03-310001508655Equity and Other Investments Human Resource Support Services Employment Hero Holdings Pty Ltd. Series E Preferred Shares (113,250 shares) Initial Acquisition Date 3/1/20222023-01-012023-12-310001508655Debt Investments Healthcare Edge Bidco B.V First-lien loan (EUR 5,811 par, due 2/2029) Initial Acquisition Date 2/24/2023 Reference Rate and Spread E + 7.00% Interest Rate 10.93% (incl. 3.25% PIK)2024-01-012024-03-310001508655tslx:MezzanineDebtInvestmentsMember2024-01-012024-03-310001508655country:GB2024-03-310001508655Equity and Other Investments Retail and Consumer Products American Achievement, Corp. Class A Units (687 units) Initial Acquisition Date 3/16/20212024-03-3100015086552023-12-310001508655Debt Investments Oil, Gas and Consumable Fuels Mach Natural Resources LP First-lien loan ($5,000 par, due 12/2026) Initial Acquisition Date 12/28/2023 Reference Rate and Spread SOFR + 6.65% Interest Rate 12.00%2023-12-310001508655Debt Investments Internet Services SMA Technologies Holdings, LLC First-lien loan ($36,833 par, due 10/2028) Initial Acquisition Date 10/31/2022 Reference Rate and Spread SOFR + 6.75% Interest Rate 12.06%2024-01-012024-03-310001508655tslx:DelayedDrawMembertslx:AsgIiLlcMember2023-12-310001508655Equity and Other Investments Pharmaceuticals TherapeuticsMD, Inc. Warrants (14,256 warrants) Initial Acquisition Date 8/5/20202024-03-310001508655tslx:MezzanineDebtInvestmentsMemberus-gaap:FairValueInputsLevel2Member2024-03-310001508655tslx:DelayedDrawAndRevolverMembertslx:ErlingLuxBidcoSarlMember2024-03-310001508655Debt Investments Retail and Consumer Products Bed Bath and Beyond Inc. Roll Up DIP term loan ($25,728 par, due 9/2024) Initial Acquisition Date 4/24/2023 Reference Rate and Spread SOFR + 7.90% Interest Rate 13.23% PIK2024-01-012024-03-310001508655Debt Investments Business Services Galileo Parent, Inc. First-lien revolving loan ($4,471 par, due 5/2030) Initial Acquisition Date 5/3/2023 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.56%2024-01-012024-03-310001508655Equity and Other Investments Structured Credit Southwick Park CLO Ltd, Series 2019-4A Structured Product ($1,000 par,due 7/2032) Initial Acquisition Date 5/25/2022 Reference Rate and Spread SOFR+ 6.51% Interest Rate 11.93%2023-12-310001508655tslx:MezzanineDebtInvestmentsMember2024-03-310001508655tslx:TwoThousandTwentyThreeTwentyFourTwentySixTwentyeightAndTwentyNineNotesMember2024-01-012024-03-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. Series D Preferred Shares (1,598,874 shares) Initial Acquisition Date 4/8/20212024-01-012024-03-310001508655tslx:TwoThousandTwentySixNotesMember2021-02-032021-02-030001508655Debt Investments Internet Services Bayshore Intermediate #2, L.P. First-lien revolving loan ($320 par, due 10/2027) Initial Acquisition Date 10/1/2021 Reference Rate and Spread SOFR + 6.85% Interest Rate 12.17%2024-03-310001508655Debt Investments Financial Services Fullsteam Operations LLC First-lien loan ($29,663 par, due 11/2029) Initial Acquisition Date 11/27/2023 Reference Rate and Spread SOFR + 8.40% Interest Rate 13.78%2023-01-012023-12-310001508655tslx:ControlledAffiliatedInvestmentsMember2023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:FullsteamOperationsLlcMember2023-12-310001508655tslx:TwoThousandTwentyThreeNotesMember2018-01-012018-01-310001508655Debt Investments Education EMS Linq, Inc. First-lien loan ($56,216 par, due 12/2027) Initial Acquisition Date 12/22/2021 Reference Rate and Spread SOFR + 6.35% Interest Rate 11.71%2023-12-310001508655us-gaap:NondesignatedMember2023-12-310001508655Equity and Other Investments Retail and Consumer Products Copper Bidco, LLC Trust Certificates (996,958 Certificates) Initial Acquisition Date 1/30/20212024-03-310001508655Debt Investments Financial Services CLGF Holdco 2, LLC Second-lien loan ($3,357 par, due 11/2028) Initial Acquisition Date 11/7/2023 Reference Rate and Spread SOFR + 12.00% Interest Rate 17.31%2024-01-012024-03-310001508655tslx:BusinessServicesMember2023-12-310001508655Debt Investments Chemicals Erling Lux Bidco SARL First-lien loan (GBP 13,388 par, due 9/2028) Initial Acquisition Date 9/6/2022 Reference Rate and Spread S + 6.75% Interest Rate 11.94%2024-01-012024-03-310001508655us-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:SecondLienDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMember2024-03-310001508655Equity and Other Investments Structured Credit Carlyle Global Market Strategies CLO Ltd, Series 2018-1A Structured Product ($1,550par,due4/2031) Initial Acquisition Date 8/11/2020 Reference Rate and Spread SOFR+6.01% Interest Rate 11.42%2023-01-012023-12-310001508655Equity and Other Investments Retail and Consumer Products2023-12-310001508655Equity and Other Investments Hotel, Gaming and Leisure IRGSE Holding Corp. Class C-1 Units (8,800,000 units) Initial Acquisition Date 12/21/20182023-12-310001508655Debt Investments Financial Services Ping Identity Holding Corp. First-lien loan ($22,727 par, due 10/2029) Initial Acquisition Date 10/17/2022 Reference Rate and Spread SOFR + 7.00% Interest Rate 12.36%2023-12-310001508655Debt Investments Financial Services Fullsteam Operations LLC First-lien loan ($29,663 par, due 11/2029) Initial Acquisition Date 11/27/2023 Reference Rate and Spread SOFR + 8.40% Interest Rate 13.78%2023-12-310001508655Debt Investments Financial Services CLGF Holdco 2, LLC First-lien loan ($3,916 par, due 11/2027) Initial Acquisition Date 11/7/2023 Reference Rate and Spread SOFR + 8.50% Interest Rate 13.81%2024-03-310001508655Debt Investments Internet Services Bayshore Intermediate #2, L.P. First-lien loan ($36,629 par, due 10/2028) Initial Acquisition Date 10/1/2021 Reference Rate and Spread SOFR + 7.60% Interest Rate 12.96% PIK2023-12-310001508655Equity and Other Investments Internet Services SMA Technologies Holdings, LLC Class A Units (1,300 units) Initial Acquisition Date 11/21/20222024-01-012024-03-310001508655us-gaap:RevolvingCreditFacilityMember2023-12-310001508655us-gaap:RetainedEarningsMember2023-01-012023-03-310001508655Debt Investments Retail and Consumer Products Cordance Operations, LLC First-lien loan ($51,007 par, due 7/2028) Initial Acquisition Date 7/25/2022 Reference Rate and Spread SOFR + 9.18% Interest Rate 14.53%2024-01-012024-03-310001508655Debt Investments Manufacturing ASP Unifrax Holdings, Inc. First-lien loan (EUR 1,023 par, due 12/2025) Initial Acquisition Date 9/14/2023 Reference Rate and Spread E + 3.75% Interest Rate 7.68%2023-01-012023-12-310001508655Equity and Other Investments Structured Credit Wind River CLO Ltd, Series 2018-3A Structured Product ($2,000par,due 1/2031) Initial Acquisition Date 12/12/2022 Reference Rate and Spread SOFR+ 5.91% Interest Rate 11.33%2023-12-310001508655tslx:BaseDividendMember2024-02-152024-02-150001508655Equity and Other Investments Structured Credit Carlyle Global Market Strategies CLO Ltd, Series 2016-1, Ltd Structured Product ($1,600par,due4/2034) Initial Acquisition Date 2/15/2023 Reference Rate and Spread SOFR+6.86% Interest Rate 12.28%2023-01-012023-12-310001508655tslx:InterestRateSwapThreeMember2024-01-012024-03-310001508655tslx:FirstLienDebtInvestmentsMember2024-01-012024-03-310001508655Interest Rate Swap Pays 3.875% Maturity Date 11/1/20242023-12-310001508655us-gaap:IncomeApproachValuationTechniqueMembertslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputDiscountRateMembersrt:WeightedAverageMember2024-03-310001508655tslx:EquityAndOtherInvestmentsMember2024-01-012024-03-310001508655tslx:DelayedDrawAndRevolverMembertslx:ForeScoutTechnologiesIncMember2023-12-310001508655tslx:InsuranceMember2023-12-310001508655Equity and Other Investments Structured Credit Signal Peak CLO LLC, Series 2018-5A Structured Product ($333 par,due 4/2031) Initial Acquisition Date 8/9/2022 Reference Rate and Spread SOFR+ 5.91% Interest Rate 11.29%2023-01-012023-12-310001508655tslx:EquityAndOtherInvestmentsMember2023-03-310001508655Debt Investments Internet Services Lucidworks, Inc. First-lien loan ($9,059 par, due 2/2027) Initial Acquisition Date 2/11/2022 Reference Rate and Spread SOFR + 7.50% Interest Rate 12.83% (incl. 3.50% PIK)2024-03-310001508655Equity and Other Investments Internet Services Piano Software, Inc. Series C-1 Preferred Shares (418,527 shares) Initial Acquisition Date 12/22/20212024-03-310001508655Debt Investments Financial Services Kyriba Corp. First-lien loan ($35,634 par, due 4/2028) Initial Acquisition Date 12/21/2023 Reference Rate and Spread SOFR + 8.50% Interest Rate 13.87% (incl. 8.50% PIK)2023-12-310001508655Interest Rate Swap Company Receives 6.95% Company Pays SOFR + 2.99% Maturity Date 8/14/20282023-12-310001508655us-gaap:AdditionalPaidInCapitalMember2024-01-012024-03-310001508655tslx:FirstLienDebtInvestmentsMember2024-03-310001508655tslx:SecondLienDebtInvestmentsMember2023-12-310001508655Equity and Other Investments Internet Services Piano Software, Inc. Series C-2 Preferred Shares (27,588 shares) Initial Acquisition Date 11/18/20222023-12-310001508655tslx:TwoThousandTwentySixNotesMemberus-gaap:InterestRateSwapMember2023-01-012023-03-310001508655tslx:ArtisanBidcoIncMembertslx:RevolverMember2024-03-310001508655tslx:TwoThousandTwentyFourNotesMember2020-02-050001508655us-gaap:FairValueInputsLevel3Member2023-12-310001508655Debt Investments Financial Services Passport Labs, Inc. Convertible Promissory Note A ($1,086 par, due 8/2026) Initial Acquisition Date 3/2/2023 Reference Rate and Spread 8.00% Interest Rate 8.00%2024-01-012024-03-310001508655tslx:NonControlledNonAffiliatedInvestmentsMember2023-12-310001508655Equity and Other Investments Business Services Sprinklr, Inc. Common Shares (315,005 shares) Initial Acquisition Date 6/24/20212023-12-310001508655Debt Investments Business Services Dye & Durham Corp. First-lien revolving loan (CAD 1,086 par, due 12/2026) Initial Acquisition Date 12/3/2021 Reference Rate and Spread C + 5.75% Interest Rate 11.20%2023-01-012023-12-310001508655Debt Investments Chemicals2023-12-310001508655Controlled Affiliated Investments2024-03-310001508655Equity and Other Investments Business Services Insight Hideaway Aggregator, L.P. Partnership Interest (329,861 units) Initial Acquisition Date 3/19/20242024-01-012024-03-310001508655Equity and Other Investments Communications Celtra Technologies, Inc. Class A Units (1,250,000 units) Initial Acquisition Date 11/19/20212024-03-310001508655tslx:FirstLienDebtInvestmentsMember2024-01-012024-03-310001508655Equity and Other Investments Structured Credit CarVal CLO III Ltd, Series 2019-2A Structured Product ($1,000par,due7/2032) Initial Acquisition Date 6/30/2022 Reference Rate and Spread SOFR+6.70% Interest Rate 12.02%2024-01-012024-03-310001508655us-gaap:IncomeApproachValuationTechniqueMembertslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputDiscountRateMember2023-12-310001508655tslx:MezzanineDebtInvestmentsMember2022-12-310001508655us-gaap:OverAllotmentOptionMember2024-04-010001508655Equity and Other Investments Pharmaceuticals TherapeuticsMD, Inc. Warrants (14,256 warrants) Initial Acquisition Date 8/5/20202024-01-012024-03-310001508655Debt Investments Human Resource Support Services PageUp People, Ltd. First-lien loan (AUD 13,400 par, due 12/2025) Initial Acquisition Date 1/11/2018 Reference Rate and Spread B + 5.00% Interest Rate 9.36%2023-01-012023-12-310001508655tslx:RevolverMembertslx:IRGSEHoldingCorpMember2024-03-310001508655srt:MaximumMemberus-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMember2024-03-310001508655us-gaap:AdditionalPaidInCapitalMember2022-12-310001508655Equity and Other Investments Structured Credit Dryden Senior Loan Fund, Series 2020-86A Structured Product ($1,500par,due7/2034) Initial Acquisition Date 8/17/2022 Reference Rate and Spread SOFR+6.76% Interest Rate 12.08%2024-03-310001508655tslx:StructuredCreditInvestmentsMember2024-03-310001508655Equity and Other Investments Business Services Mitnick TA Aggregator, L.P. Membership Interest (0.43% ownership) Initial Acquisition Date 5/2/20222023-01-012023-12-310001508655Debt Investments, Manufacturing, Skylark UK DebtCo Limited, First-lien loan ($16,340 par, due 9/2030), Initial Acquisition Date 9/7/2023, Reference Rate and Spread, SOFR + 5.75%, Interest Rate 11.06%2024-01-012024-03-310001508655tslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Member2024-03-310001508655Equity and Other Investments Financial Services Passport Labs, Inc. 17,534 Warrants Initial Acquisition Date 4/28/20212023-12-310001508655Equity and Other Investments Hotel, Gaming and Leisure IRGSE Holding Corp. Class C-1 Units (8,800,000 units) Initial Acquisition Date 12/21/20182024-01-012024-03-310001508655Equity and Other Investments Human Resource Support Services Employment Hero Holdings Pty Ltd. Series E Preferred Shares (113,250 shares) Initial Acquisition Date 3/1/20222023-12-310001508655Equity and Other Investments Structured Credit Eaton CLO Ltd, Series 2020-1A Structured Product ($1,000par,due10/2034) Initial Acquisition Date 8/11/2022 Reference Rate and Spread SOFR+6.51% Interest Rate 11.91%2023-12-310001508655Equity and Other Investments Internet Services Bayshore Intermediate #2, L.P. Co-Invest Common Units (8,837,008 units) Initial Acquisition Date 10/1/20212024-01-012024-03-310001508655Equity and Other Investments Healthcare Raptor US Buyer II Corp. 20,268 Ordinary Shares Initial Acquisition Date 3/24/20232024-03-310001508655us-gaap:FinancialServicesSectorMember2024-03-310001508655tslx:TwentyTwentyThreeNotesMember2024-01-012024-03-310001508655Debt Investments Business Services Dye & Durham Corp. First-lien loan (CAD 37,874 par, due 12/2027) Initial Acquisition Date 12/3/2021 Reference Rate and Spread C + 5.75% Interest Rate 11.04%2024-01-012024-03-310001508655Debt Investments Transportation Project44, Inc. First-lien loan ($35,095 par, due 11/2027 Initial Acquisition Date 11/12/2021 Reference Rate and Spread SOFR + 6.40% Interest Rate 11.71%2024-01-012024-03-310001508655Debt Investments Human Resource Support Services Employment Hero Holdings Pty Ltd. First-lien loan (AUD 50,000 par, due 12/2026) Initial Acquisition Date 12/6/2021 Reference Rate and Spread B + 6.25% Interest Rate 10.65%2024-01-012024-03-310001508655tslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel2Member2024-03-310001508655Debt Investments Financial Services TradingScreen, Inc. First-lien loan ($47,198 par, due 4/2027) Initial Acquisition Date 4/30/2021 Reference Rate and Spread SOFR + 6.35% Interest Rate 11.73%2023-01-012023-12-310001508655Debt Investments Human Resource Support Services PayScale Holdings, Inc. First-lien loan ($71,014 par, due 5/2027) Initial Acquisition Date 5/3/2019 Reference Rate and Spread SOFR + 6.35% Interest Rate 11.58%2024-03-310001508655Debt Investments Internet Services CrunchTime Information, Systems, Inc. First-lien loan ($59,350 par, due 6/2028) Initial Acquisition Date 6/17/2022 Reference Rate and Spread SOFR + 6.00% Interest Rate 11.33%2024-03-310001508655srt:MaximumMemberus-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:SecondLienDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMember2024-03-310001508655Debt Investments Business Services Azurite Intermediate Holdings, Inc. First-lien loan ($13,062 par, due 3/2031) Initial Acquisition Date 3/19/2024 Reference Rate and Spread SOFR + 6.50% Interest Rate 11.83%2024-01-012024-03-310001508655Debt Investments, Manufacturing, Skylark UK DebtCo Limited, First-lien loan (GBP 16,640 par, due 9/2030), Initial Acquisition Date 9/7/2023, Reference Rate and Spread, S + 5.75%, Interest Rate 11.00%2024-03-310001508655Equity and Other Investments Financial Services Newport Parent Holdings, L.P. Class A-2 Units (131,569 units) Initial Acquisition Date 12/10/20202024-03-310001508655Debt Investments Financial Services BlueSnap, Inc. First-lien loan ($41,790 par, due 10/2025) Initial Acquisition Date 10/25/2019 Reference Rate and Spread SOFR + 7.15% Interest Rate 12.46%2024-01-012024-03-310001508655Controlled Affiliated Investments2024-01-012024-03-310001508655Equity and Other Investments Structured Credit Benefit Street Partners CLO Ltd, Series 2015-8A Structured Product ($1,425par,due1/2031) Initial Acquisition Date 9/13/2022 Reference Rate and Spread SOFR+3.01% Interest Rate 8.43%2023-01-012023-12-310001508655Equity and Other Investments Internet Services SMA Technologies Holdings, LLC Class B Units (923,250 units) Initial Acquisition Date 11/21/20222024-03-310001508655tslx:DelayedDrawMembertslx:IbisIntermediateCoMember2024-03-310001508655us-gaap:TreasuryStockCommonMember2022-12-310001508655Debt Investments Business Services Mitnick Corporate Purchaser, Inc First-lien loan ($329 par, due 5/2029) Initial Acquisition Date 5/2/2022 Reference Rate and Spread SOFR + 4.50% Interest Rate 9.98%2023-01-012023-12-310001508655tslx:SecondLienDebtInvestmentsMember2024-01-012024-03-310001508655us-gaap:AssetPledgedAsCollateralMember2024-03-310001508655Equity and Other Investments Retail and Consumer Products Copper Bidco, LLC Trust Certificates (132,928 Certificates) Initial Acquisition Date 12/7/20202023-12-310001508655us-gaap:FairValueInputsLevel3Member2024-01-012024-03-310001508655Equity and Other Investments Business Services ReliaQuest, LLC Class A-2 Units (2,989 units) Initial Acquisition Date 6/21/20222023-01-012023-12-310001508655Debt Investments Hotel, Gaming and Leisure Equinox Holdings, Inc First-lien loan ($48,044 par, due 3/2029) Initial Acquisition Date 3/8/2024 Reference Rate and Spread SOFR + 8.25% Interest Rate 13.56%(incl. 4.13% PIK)2024-01-012024-03-310001508655Debt Investments Healthcare Raptor US Buyer II Corp. First-lien loan ($15,569 par, due 3/2029) Initial Acquisition Date 3/24/2023 Reference Rate and Spread SOFR + 6.75% Interest Rate 12.10%2023-12-310001508655Equity and Other Investments Human Resource Support Services DaySmart Holdings, LLC Class A Units (166,811 units) Initial Acquisition Date 12/18/20202023-01-012023-12-310001508655Equity and Other Investments Internet Services Lucidworks, Inc. Series F Preferred Shares (199,054 shares) Initial Acquisition Date 8/2/20192023-12-310001508655Equity and Other Investments Structured Credit MidOcean Credit CLO Ltd, Series 2018-9A Structured Product ($1,100 par, due 7/2031) Initial Acquisition Date 6/1/2022 Reference Rate and Spread SOFR+ 6.31% Interest Rate 11.73%2023-12-310001508655Debt Investments Human Resource Support Services Madcap Software, Inc. First-lien loan ($32,500 par, due 12/2026) Initial Acquisition Date 12/15/2023 Reference Rate and Spread SOFR + 6.10% Interest Rate 11.46%2023-12-310001508655Debt Investments Financial Services CLGF Holdco 2, LLC Second-lien loan ($3,357 par, due 11/2028) Initial Acquisition Date 11/7/2023 Reference Rate and Spread SOFR + 12.00% Interest Rate 17.31%2024-03-310001508655tslx:ValuationTechniqueCostOfInvestmentsMembertslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Member2023-12-310001508655Debt Investments Business Services Netwrix Corp. First-lien loan ($36,594 par, due 6/2029) Initial Acquisition Date 5/9/2022 Reference Rate and Spread SOFR + 5.00% Interest Rate 10.39%2023-12-310001508655tslx:PingIdentityCorporationMembertslx:RevolverMember2023-12-310001508655tslx:RevolverMembertslx:DiscoParentIncMember2024-03-310001508655Debt Investments Healthcare Merative L.P. First-lien loan ($70,103 par, due 6/2028) Initial Acquisition Date 6/30/2022 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.56%2024-01-012024-03-310001508655Equity and Other Investments Hotel, Gaming and Leisure IRGSE Holding Corp. Class A Units (33,790,171 units) Initial Acquisition Date 12/21/20182024-03-310001508655tslx:DelayedDrawAndRevolverMembertslx:RapidDataGmbhUnternehmensberatungMember2023-12-310001508655Debt Investments Business Services Information Clearinghouse, LLC and MS Market Service, LLC First-lien loan ($17,640 par, due 12/2026) Initial Acquisition Date 12/20/2021 Reference Rate and Spread SOFR + 6.65% Interest Rate 12.02%2023-01-012023-12-310001508655Debt Investments Office Products USR Parent, Inc. ABL FILO term loan ($16,500 par, due 4/2027) Initial Acquisition Date 4/25/2022 Reference Rate and Spread SOFR + 6.50% Interest Rate 11.83%2024-01-012024-03-310001508655Debt Investments Human Resource Support Services PageUp People, Ltd. First-lien loan ($ 9,579 par, due 12/2025) Initial Acquisition Date 10/28/2021 Reference Rate and Spread S + 5.10% Interest Rate 10.43%2024-03-310001508655tslx:InterestRateSwapOneMember2023-01-012023-03-310001508655Debt Investments Communications Banyan Software Holdings, LLC First-lien loan ($29,739 par, due 10/2026) Initial Acquisition Date 1/27/2023 Reference Rate and Spread SOFR + 7.35% Interest Rate 12.71%2023-01-012023-12-310001508655tslx:EducationMember2024-03-310001508655Debt Investments Retail and Consumer Products PDI TA Holdings, Inc. First-lien loan ($14,410 par, due 2/2031) Initial Acquisition Date 2/1/2024 Reference Rate and Spread E + 6.50% Interest Rate 10.43%2024-03-310001508655Equity and Other Investments Pharmaceuticals TherapeuticsMD, Inc. 14,256 Warrants Initial Acquisition Date 8/5/20202023-01-012023-12-310001508655tslx:InternetServicesMember2023-12-310001508655tslx:RealizedCapitalGainsAccruedPriorToMarchThirtyFirstTwoThousandFourteenMembertslx:InvestmentAdvisoryAgreementMember2011-04-152011-04-150001508655Debt Investments Retail and Consumer Products American Achievement, Corp. First-lien loan ($1,352 par, due 9/2026) Initial Acquisition Date 6/10/2021 Reference Rate and Spread SOFR + 14.10% Interest Rate 18.94% PIK2023-01-012023-12-310001508655tslx:LeverageWaiverMembertslx:InvestmentAdvisoryAgreementMember2011-04-152011-04-150001508655Debt Investments Human Resource Support Services PageUp People, Ltd. First-lien loan ($10,557 par, due 12/2025) Initial Acquisition Date 10/28/2021 Reference Rate and Spread SOFR + 5.10% Interest Rate 10.45%2023-12-310001508655tslx:NonControlledNonAffiliatedInvestmentsMember2024-01-012024-03-310001508655Debt Investments Hotel, Gaming and Leisure IRGSE Holding Corp. First-lien revolving loan ($30,102 par, due 6/2024) Initial Acquisition Date 12/21/2018 Reference Rate and Spread SOFR + 9.65% Interest Rate 14.96%2024-03-310001508655tslx:AssetValuationWaterfallMemberus-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMember2024-03-310001508655Debt Investments Education EMS Linq, Inc. First-lien loan ($56,216 par, due 12/2027) Initial Acquisition Date 12/22/2021 Reference Rate and Spread SOFR + 6.35% Interest Rate 11.68%2024-03-310001508655Interest Rate Swap Company Receives SOFR + 2.54% Maturity Date 11/1/20242024-01-012024-03-310001508655tslx:AdministrationAgreementMember2023-11-012023-11-300001508655Controlled Affiliated Investments2022-12-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. Series C Preferred Shares (1,816,295 shares) Initial Acquisition Date 4/8/20212023-12-310001508655Equity and Other Investments Financial Services CLGF Holdco 2, LLC 334,682 Warrants Initial Acquisition Date 11/7/20232024-03-310001508655Equity and Other Investments Structured Credit CIFC CLO Ltd, Series 2018-3A Structured Product ($1,000par,due7/2031)Initial Acquisition Date 6/16/2022 Reference Rate and Spread SOFR+5.76% Interest Rate 11.06%2024-01-012024-03-310001508655Equity and Other Investments Structured Credit Octagon Investment Partners 18 Ltd, Series 2018 – 18A Structured Product ($1,000 par, due 4/2031) Initial Acquisition Date 7/26/2022 Reference Rate and Spread SOFR+ 2.96% Interest Rate 8.36%2023-12-310001508655Equity and Other Investments Internet Services Bayshore Intermediate #2, L.P. Co-Invest Common Units (8,837,008 units) Initial Acquisition Date 10/1/20212023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:ForeScoutTechnologiesIncMember2024-03-310001508655Debt Investments Financial Services Alaska Bidco Oy First-lien loan (EUR 727 par, due 5/2030) Initial Acquisition Date 5/30/2023 Reference Rate and Spread E + 6.25% Interest Rate 10.15%2024-03-310001508655tslx:DelayedDrawAndRevolverMembertslx:CordanceOperationsLlcMember2023-12-310001508655tslx:DelayedDrawMembertslx:ArrowbuyerIncMember2023-12-310001508655Debt Investments Retail and Consumer Products American Achievement, Corp. First-lien loan ($27,046 par, due 9/2026) Initial Acquisition Date 9/30/2015 Reference Rate and Spread SOFR + 6.35% Interest Rate 11.19% PIK2023-12-3100015086552023-01-012023-12-310001508655Interest Rate Swap Company Receives 3.875% Company Pays SOFR + 2.72% Maturity Date 11/1/20242024-03-310001508655Equity and Other Investments Structured Credit Crown Point CLO Ltd, Series 2021-10A Structured Product ($1,000par,due7/2034) Initial Acquisition Date 6/14/2022 Reference Rate and Spread SOFR+7.11% Interest Rate 12.43%2024-01-012024-03-310001508655Equity and Other Investments Business Services ReliaQuest, LLC 90,634 Warrants Initial Acquisition Date 12/20/20232024-01-012024-03-310001508655Equity and Other Investments Structured Credit Dryden Senior Loan Fund, Series 2018-55A Structured Product ($1,000par,due4/2031)Initial Acquisition Date 7/25/2022 Reference Rate and Spread SOFR+3.11% Interest Rate 8.43%2024-03-310001508655Debt Investments Manufacturing Aptean, Inc First-lien loan ($7,922 par, due 1/2031) Initial Acquisition Date 1/30/2024 Reference Rate and Spread SOFR + 5.25% Interest Rate 10.57%2024-01-012024-03-310001508655tslx:InvestmentAdvisoryAgreementMember2023-11-012023-11-300001508655us-gaap:HealthcareSectorMember2024-03-310001508655Equity and Other Investments Marketing Services Validity, Inc. Series A Preferred Shares (3,840,000 shares) Initial Acquisition Date 5/31/20182024-03-310001508655Debt Investments Education Kangaroo Bidco AS First-lien loan ($25,582 par, due 11/2030) Initial Acquisition Date 11/2/2023 Reference Rate and Spread SOFR + 7.50% Interest Rate 12.94%2023-12-310001508655tslx:RevolverMembertslx:AvalaraIncMember2023-12-310001508655Controlled Affiliated Investments2023-12-310001508655tslx:InterestRateSwapSixMember2024-01-012024-03-310001508655tslx:CommunicationsMember2024-03-310001508655tslx:RevolverMembertslx:GalileoParentincMember2024-03-310001508655Debt Investments Human Resource Support Services bswift, LLC First-lien loan ($44,358 par, due 11/2028) Initial Acquisition Date 11/7/2022 Reference Rate and Spread SOFR + 6.63% Interest Rate 12.03%2023-01-012023-12-310001508655tslx:SupplementalDividendMember2023-02-160001508655tslx:MidwestMember2023-12-310001508655Debt Investments Chemicals Erling Lux Bidco SARL First-lien loan (NOK 7,427 par, due 9/2028) Initial Acquisition Date 9/6/2022 Reference Rate and Spread N + 6.75% Interest Rate 11.45%2024-03-310001508655Equity and Other Investments Retail and Consumer Products American Achievement, Corp. Class A Units (687 units) Initial Acquisition Date 3/16/20212024-01-012024-03-310001508655Debt Investments, Manufacturing, ASP Unifrax Holdings, Inc, Secured Note ($1226 par, due 9/2028) Initial Acquisition Date 12/19/2023 Reference Rate and Spread 5.25% Interest Rate 5.25%2024-01-012024-03-310001508655Debt Investments Communications Babylon Finco Limited First-lien loan ($1,557 par, due 1/2031) Initial Acquisition Date 1/26/2024 Reference Rate and Spread SOFR + 6.25% Interest Rate 11.57%2024-03-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. Series D Preferred Shares (1,240,740 shares) Initial Acquisition Date 5/11/20212023-01-012023-12-310001508655tslx:MarketingServicesMember2024-03-310001508655us-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMember2024-03-310001508655tslx:DelayedDrawAndRevolverMembertslx:KyribaCorpMember2023-12-310001508655tslx:LeverageWaiverMembertslx:InvestmentAdvisoryAgreementMember2023-01-012023-03-310001508655us-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:SecondLienDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMember2023-12-310001508655Debt Investments Transportation Ben Nevis Midco Limited First-lien loan ($3,296 par, due 3/2028) Initial Acquisition Date 3/26/2024 Reference Rate and Spread SOFR + 5.00% Interest Rate 10.31%2024-03-310001508655us-gaap:NondesignatedMemberus-gaap:InterestRateSwapMember2023-01-012023-03-310001508655Debt Investments Business Services BCTO Ignition Purchaser, Inc. First-lien holdco loan ($31,935 par, due 10/2030) Initial Acquisition Date 4/18/2023 Reference Rate and Spread SOFR + 9.00% Interest Rate 14.40% PIK2023-12-310001508655tslx:TwoThousandTwentyFourNotesMember2019-11-300001508655Equity and Other Investments Human Resource Support Services Axonify, Inc. Class A-1 Units (3,780,000 units) Initial Acquisition Date 5/5/20212023-01-012023-12-310001508655Interest Rate Swap Company Pays SOFR + 2.72% Maturity Date 11/1/20242023-12-310001508655Debt Investments Manufacturing ASP Unifrax Holdings, Inc. First-lien loan ($1,130 par, due 12/2025) Initial Acquisition Date 8/25/2023 Reference Rate and Spread SOFR + 3.90% Interest Rate 9.25%2023-12-310001508655Equity and Other Investments Business Services Warrior TopCo LP Class A Units (423,728 units) Initial Acquisition Date 7/7/20232023-01-012023-12-310001508655tslx:EquityAndOtherInvestmentsMembertslx:AssetValuationWaterfallMemberus-gaap:FairValueInputsLevel3Member2023-12-310001508655Debt Investments Healthcare BCTO Ace Purchaser, Inc. Second-lien loan ($5,623 par, due 1/2030) Initial Acquisition Date 1/23/2023 Reference Rate and Spread SOFR + 10.70% Interest Rate 16.10%2023-12-310001508655Debt Investments, Manufacturing, Avalara, Inc, First-lien loan ($38,636 par, due 10/2028), Initial Acquisition Date10/19/2022, Reference Rate and Spread, SOFR + 7.25%, Interest Rate 12.56%2024-03-310001508655Interest Rate Swap Company Pays SOFR + 2.44% Maturity Date 3/1/20292024-03-310001508655us-gaap:RevolvingCreditFacilityMember2024-04-240001508655tslx:RevolverMembertslx:GalileoParentincMember2023-12-310001508655Equity and Other Investments Retail and Consumer Products Neuintel, LLC Class A Units (1,176,494 units) Initial Acquisition Date 12/20/20212024-03-310001508655tslx:TwentyTwentyNineNotesMember2024-01-012024-01-310001508655Debt Investments Business Services Hornetsecurity Holding GmbH First-lien loan (EUR 3,150 par, due 11/2029) Initial Acquisition Date 11/14/2022 Reference Rate and Spread E + 6.50% Interest Rate 10.50%2023-12-310001508655Debt Investments Internet Services Arrow Buyer, Inc. First-lien loan ($33,125 par, due 7/2030) Initial Acquisition Date 6/30/2023 Reference Rate and Spread SOFR + 6.50% Interest Rate 11.85%2023-12-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. 633,376 Warrants Initial Acquisition Date 9/21/20182024-03-310001508655Equity and Other Investments Oil, Gas and Consumable Fuels TRP Assets, LLC Partnership Interest (1.89% ownership) Initial Acquisition Date 8/25/20222024-01-012024-03-310001508655Equity and Other Investments Financial Services Oxford Square Capital Corp. Common Shares (1,620 shares) Initial Acquisition Date 8/5/20152023-12-310001508655Equity and Other Investments Structured Credit Jefferson Mill CLO Ltd, Series 2015-1A Structured Product ($1,000par,due 10/2031) Initial Acquisition Date 5/23/2022 Reference Rate and Spread SOFR+ 3.81% Interest Rate 9.22%2023-12-310001508655Equity and Other Investments Structured Credit Wind River CLO Ltd, Series 2018-3A Structured Product ($2,000par,due 1/2031) Initial Acquisition Date 12/12/2022 Reference Rate and Spread SOFR+ 5.91% Interest Rate 11.23%2024-01-012024-03-310001508655Equity and Other Investments Business Services ReliaQuest, LLC Class A-1 Units (637,713 units) Initial Acquisition Date 11/23/20212024-01-012024-03-310001508655tslx:SecondLienDebtInvestmentsMember2024-03-310001508655tslx:DelayedDrawMembertslx:BearOpCoLLCMember2024-03-310001508655Equity and Other Investments Business Services2023-12-310001508655Debt Investments Hotel, Gaming and Leisure ASG II, LLC First-lien loan ($64,457 par, due 5/2028) Initial Acquisition Date 5/25/2022 Reference Rate and Spread SOFR + 6.40% Interest Rate 11.71%2024-01-012024-03-310001508655Debt Investments Hotel, Gaming and Leisure ASG II, LLC First-lien loan ($64,457 par, due 5/2028) Initial Acquisition Date 5/25/2022 Reference Rate and Spread SOFR + 6.40% Interest Rate 11.71%2024-03-310001508655Equity and Other Investments Human Resource Support Services DaySmart Holdings, LLC Class A Units (166,811 units) Initial Acquisition Date 12/18/20202023-12-310001508655us-gaap:AdditionalPaidInCapitalMember2023-01-012023-03-310001508655Debt Investments Communications2024-03-310001508655tslx:HumanResourceSupportServicesMember2024-03-310001508655tslx:ReliaQuestHoldingsLLCMembertslx:DelayedDrawRevolverPreferredEquityMember2023-12-310001508655Interest Rate Swap Company Receives 3.875% Company SOFR + 2.51% Maturity Date 11/1/20242023-12-310001508655Debt Investments Financial Services Passport Labs, Inc. First-lien loan ($24,603 par, due 4/2026) Initial Acquisition Date 4/28/2021 Reference Rate and Spread SOFR + 8.40% Interest Rate 13.75%2023-12-310001508655Equity and Other Investments Oil, Gas and Consumable Fuels2024-03-310001508655tslx:DelayedDrawMembertslx:BctoBluebillBuyerIncMember2024-03-310001508655tslx:FutureRealizedCapitalGainsPriorToAprilFirstTwoThousandFourteenMembertslx:InvestmentAdvisoryAgreementMember2020-03-312020-03-310001508655Debt Investments Healthcare Homecare Software Solutions, LLC First-lien loan ($65,000 par, due 10/2026) Initial Acquisition Date 10/6/2021 Reference Rate and Spread SOFR + 5.70% Interest Rate 11.06%2023-01-012023-12-310001508655us-gaap:InvestmentAffiliatedIssuerControlledMember2024-01-012024-03-310001508655tslx:EquityAndOtherInvestmentsMembertslx:AssetValuationWaterfallMemberus-gaap:FairValueInputsLevel3Member2024-03-310001508655country:SE2024-03-310001508655Debt Investments Internet Services Bayshore Intermediate #2, L.P. First-lien loan ($37,064 par, due 10/2028) Initial Acquisition Date 10/1/2021 Reference Rate and Spread SOFR + 7.60% Interest Rate 12.92 PIK%2024-03-310001508655Equity and Other Investments Retail and Consumer Products American Achievement, Corp. Class A Units (687 units) Initial Acquisition Date 3/16/20212023-01-012023-12-310001508655country:CA2023-12-310001508655tslx:DelayedDrawMembertslx:AsgIiLlcMember2024-03-310001508655tslx:TwoThousandTwentyFourNotesMember2020-02-052020-02-050001508655Debt Investments Manufacturing Skylark UK DebtCo Limited First-lien loan (EUR 4,851 par, due 9/2030) Initial Acquisition Date 9/7/2023 Reference Rate and Spread E + 6.25% Interest Rate 10.18%2023-12-310001508655Debt Investments Financial Services BTRS Holdings, Inc. First-lien loan ($47,051 par, due 12/2028) Initial Acquisition Date 12/16/2022 Reference Rate and Spread SOFR + 8.00% Interest Rate 13.38%2023-01-012023-12-310001508655Debt Investments Business Services ReliaQuest Holdings, LLC First-lien loan ($82,626 par, due 10/2026) Initial Acquisition Date 10/8/2020 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.63%2023-12-310001508655Debt Investments Human Resource Support Services PageUp People, Ltd. First-lien loan (GBP 2,761 par, due 12/2025) Initial Acquisition Date 10/28/2021 Reference Rate and Spread S + 5.03% Interest Rate 10.24%2024-01-012024-03-310001508655Debt Investments Education Destiny Solutions Parent Holding Company First-lien loan ($59,550 par, due 6/2026) Initial Acquisition Date 6/8/2021 Reference Rate and Spread SOFR + 5.85% Interest Rate 11.21%2023-01-012023-12-310001508655tslx:DelayedDrawMembertslx:LaramieEnergyLLCMember2024-03-310001508655tslx:TwoThousandTwentyEightNotesMember2023-08-142023-08-140001508655Debt Investments Manufacturing Skylark UK DebtCo Limited First-lien loan (GBP 16,640 par, due 9/2030) Initial Acquisition Date 9/7/2023 Reference Rate and Spread S + 6.25% Interest Rate 11.52%2023-12-310001508655Debt Investments Human Resource Support Services HireVue, Inc. First-lien loan ($54,113 par, due 5/2029) Initial Acquisition Date 5/3/2023 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.63%2023-12-310001508655Debt Investments Retail and Consumer Products Tango Management Consulting, LLC First-lien loan ($57,967 par, due 12/2027) Initial Acquisition Date 12/1/2021 Reference Rate and Spread SOFR + 6.90% Interest Rate 12.23%2024-01-012024-03-310001508655Equity and Other Investments Business Services ReliaQuest, LLC Class A-3 Units (16,957 units) Initial Acquisition Date 11/10/20232024-01-012024-03-310001508655Debt Investments Business Services Dye & Durham Corp. First-lien loan (CAD 37,874 par, due 12/2027) Initial Acquisition Date 12/3/2021 Reference Rate and Spread C + 5.75% Interest Rate 11.04%2024-03-310001508655Equity and Other Investments Structured Credit Bain Capital Credit CLO Ltd, Series 2018-1A Structured Product ($500par,due4/2031) Initial Acquisition Date 10/15/2020 Reference Rate and Spread SOFR+5.61% Interest Rate 11.02%2023-01-012023-12-310001508655tslx:TwoThousandTwentyNineNotesMember2024-01-012024-03-310001508655tslx:RevolvingCreditFacilityMaturityOnFebruary42026Member2024-04-240001508655tslx:TwoThousandTwentyEightNotesMember2024-03-310001508655us-gaap:FairValueInputsLevel3Member2023-01-012023-03-310001508655us-gaap:CommonStockMember2024-03-050001508655Equity and Other Investments Structured Credit Southwick Park CLO Ltd, Series 2019-4A Structured Product ($1,000 par,due 7/2032) Initial Acquisition Date 5/25/2022 Reference Rate and Spread SOFR+ 6.51% Interest Rate 11.83%2024-03-310001508655tslx:DelayedDrawMembertslx:TRPAssetsLLCMember2024-03-310001508655tslx:WestMember2024-03-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. 280,000 Series C Warrants Initial Acquisition Date 2/28/20202024-03-310001508655tslx:MezzanineDebtInvestmentsMember2023-01-012023-03-310001508655Debt Investments Internet Services LeanTaaS Holdings, Inc. First-lien loan ($36,966 par, due 7/2028) Initial Acquisition Date 7/12/2022 Reference Rate and Spread SOFR + 7.50% Interest Rate 12.85%2023-01-012023-12-310001508655Debt Investments Financial Services BTRS Holdings, Inc. First-lien loan ($47,526 par, due 12/2028) Initial Acquisition Date 12/16/2022 Reference Rate and Spread SOFR + 8.00% Interest Rate 13.33%2024-01-012024-03-310001508655Debt Investments Human Resource Support Services HireVue, Inc. First-lien loan ($53,978 par, due 5/2029) Initial Acquisition Date 5/3/2023 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.56%2024-01-012024-03-310001508655tslx:DelayedDrawMembertslx:OutsystemsLuxcoMember2024-03-310001508655Derivative Interest Rate Swap2024-03-310001508655Debt Investments Financial Services Ibis US Blocker Co. First-lien loan ($15,958 par, due 5/2028) Initial Acquisition Date 5/28/2021 Reference Rate and Spread SOFR + 8.40% Interest Rate 13.79% (PIK)2023-12-310001508655tslx:TwentyTwentySixNotesMember2021-02-032021-02-030001508655Debt Investments Communications Celtra Technologies, Inc. First-lien loan ($34,038 par, due 11/2026) Initial Acquisition Date 11/19/2021 Reference Rate and Spread SOFR + 6.35% Interest Rate 11.71%2023-12-310001508655Debt Investments Other Omnigo Software, LLC First-lien loan ($39,943 par, due 3/2026) Initial Acquisition Date 3/31/2021 Reference Rate and Spread SOFR + 6.60% Interest Rate 11.96%2023-12-310001508655us-gaap:RevolvingCreditFacilityMembersrt:MinimumMember2024-03-3100015086552024-05-010001508655Debt Investments Retail and Consumer Products Tango Management Consulting, LLC First-lien loan ($57,967 par, due 12/2027) Initial Acquisition Date 12/1/2021 Reference Rate and Spread SOFR + 6.90% Interest Rate 12.23%2024-03-310001508655Equity and Other Investments Structured Credit Bain Capital Credit CLO Ltd, Series 2018-1A Structured Product ($500par,due4/2031) Initial Acquisition Date 10/15/2020 Reference Rate and Spread SOFR+5.61% Interest Rate 11.02%2023-12-310001508655Equity and Other Investments Structured Credit MidOcean Credit CLO Ltd, Series 2016-6A Structured Product ($3,500 par, due 4/2033) Initial Acquisition Date 5/23/2022 Reference Rate and Spread SOFR+ 3.78% Interest Rate 9.10%2024-01-012024-03-310001508655tslx:RevolverMembertslx:BayshoreIntermediate2LPMember2024-03-310001508655tslx:DelayedDrawMembertslx:LucidworksIncMember2024-03-310001508655Equity and Other Investments Business Services ReliaQuest, LLC 90,634 Warrants Initial Acquisition Date 12/20/20232024-03-310001508655Debt Investments Communications IntelePeer Holdings, Inc. First-lien loan ($33,367 par, due 12/2024) Initial Acquisition Date 12/2/2019 Reference Rate and Spread SOFR + 8.40% Interest Rate 13.71%2024-01-012024-03-310001508655Equity and Other Investments Financial Services CLGF Holdco 2, LLC 334,682 Warrants Initial Acquisition Date 11/7/20232024-01-012024-03-310001508655Debt Investments Business Services Artisan Bidco, Inc First-lien loan (EUR 17,691 par, due 11/2029) Initial Acquisition Date 11/7/2023 Reference Rate and Spread E + 7.00% Interest Rate 10.92%2024-01-012024-03-310001508655Debt Investments Healthcare Edge Bidco B.V First-lien loan (EUR 3,850 par, due 2/2029) Initial Acquisition Date 2/24/2023 Reference Rate and Spread E + 7.00% Interest Rate 16.10% (incl. 3.25% PIK)2023-12-310001508655Debt Investments Business Services OutSystems Luxco SARL First-lien loan (EUR 3,004 par, due 12/2028) Initial Acquisition Date 12/8/2022 Reference Rate and Spread E + 5.75% Interest Rate 9.58%2024-01-012024-03-310001508655us-gaap:OverAllotmentOptionMember2024-04-012024-04-010001508655us-gaap:FairValueInputsLevel2Member2024-03-310001508655tslx:ControlledAffiliatedInvestmentsMember2024-03-310001508655Debt Investments Human Resource Support Services Axonify, Inc. First-lien loan ($42,299 par, due 5/2027) Initial Acquisition Date 5/5/2021 Reference Rate and Spread SOFR + 7.65% Interest Rate 12.92%2024-01-012024-03-310001508655Equity and Other Investments Business Services Dye & Durham, Ltd. Common Shares (126,968 shares) Initial Acquisition Date 12/3/20212024-01-012024-03-310001508655tslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Member2024-01-012024-03-310001508655Debt Investments Business Services Alpha Midco, Inc. First-lien loan ($68,928 par, due 8/2025) Initial Acquisition Date 8/15/2019 Reference Rate and Spread SOFR + 7.63% Interest Rate 12.93%2024-01-012024-03-310001508655Equity and Other Investments Retail and Consumer Products Neuintel, LLC Class A Units (1,176,494 units) Initial Acquisition Date 12/20/20212024-01-012024-03-310001508655Debt Investments Retail and Consumer Products Bed Bath and Beyond Inc. Roll Up DIP term loan ($25,931 par, due 9/2024) Initial Acquisition Date 4/24/2023 Reference Rate and Spread SOFR + 7.90% Interest Rate 13.26% (incl. 13.26% PIK)2023-01-012023-12-310001508655Debt Investments Healthcare Homecare Software Solutions, LLC First-lien loan ($65,000 par, due 10/2026) Initial Acquisition Date 10/6/2021 Reference Rate and Spread SOFR + 5.70% Interest Rate 11.13%2024-01-012024-03-310001508655Debt Investments Retail and Consumer Products American Achievement, Corp. First-lien loan ($27,003 par, due 9/2026) Initial Acquisition Date 9/30/2015 Reference Rate and Spread SOFR + 6.35% Interest Rate 11.68% (incl. 11.18% PIK)2024-03-310001508655Debt Investments Internet Services EDB Parent, LLC First-lien loan ($65,167 par, due 7/2028) Initial Acquisition Date 7/7/2022 Reference Rate and Spread SOFR + 6.75% Interest Rate 12.08%2024-01-012024-03-310001508655Debt Investments Retail and Consumer Products Bed Bath and Beyond Inc. ABL FILO term loan ($14,065 par, due 8/2027) Initial Acquisition Date 9/2/2022 Reference Rate and Spread SOFR + 9.90% Interest Rate 15.26%2023-12-310001508655tslx:TwoThousandTwentyFourNotesMember2024-01-012024-03-310001508655tslx:DelayedDrawAndRevolverMembertslx:ExtraHopNetworksIncMember2023-12-310001508655Equity and Other Investments Structured Credit Signal Peak CLO LLC, Series 2018-5A Structured Product ($333 par,due 4/2031) Initial Acquisition Date 8/9/2022 Reference Rate and Spread SOFR+ 5.91% Interest Rate 11.29%2023-12-310001508655tslx:TwoThousandTwentySixNotesMember2024-03-310001508655tslx:DelayedDrawAndRevolverMembertslx:RapidDataGmbhUnternehmensberatungMember2024-03-310001508655Equity and Other Investments Structured Credit Carlyle Global Market Strategies CLO Ltd, Series 2014-4RA Structured Product ($1,000par,due7/2030) Initial Acquisition Date 5/26/2022 Reference Rate and Spread SOFR+3.16% Interest Rate 8.56%2023-12-310001508655tslx:FirstLienDebtInvestmentsMember2023-01-012023-03-310001508655Debt Investments, Manufacturing, Avalara, Inc, First-lien loan ($38,636 par, due 10/2028), Initial Acquisition Date10/19/2022, Reference Rate and Spread, SOFR + 7.25%, Interest Rate 12.56%2024-01-012024-03-310001508655Debt Investments Business Services2024-03-310001508655Equity and Other Investments Internet Services2024-03-310001508655Debt Investments Retail and Consumer Products Cordance Operations, LLC First-lien loan ($49,543 par, due 7/2028) Initial Acquisition Date 7/25/2022 Reference Rate and Spread SOFR + 9.25% Interest Rate 14.66%2023-01-012023-12-310001508655us-gaap:IncomeApproachValuationTechniqueMembertslx:MezzanineDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputDiscountRateMember2023-12-310001508655Equity and Other Investments Education EMS Linq, Inc. Class B Units (5,522,526 units) Initial Acquisition Date 12/22/20212024-01-012024-03-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. Series D Preferred Shares (1,598,874 shares) Initial Acquisition Date 4/8/20212023-01-012023-12-310001508655Equity and Other Investments Structured Credit Benefit Street Partners CLO Ltd, Series 2015-8A Structured Product ($1,425par,due1/2031) Initial Acquisition Date 9/13/2022 Reference Rate and Spread SOFR+3.01% Interest Rate 8.43%2023-12-310001508655Debt Investments Business Services ReliaQuest Holdings, LLC First-lien loan ($82,626 par, due 10/2026) Initial Acquisition Date 10/8/2020 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.56%2024-03-310001508655us-gaap:RevolvingCreditFacilityMemberus-gaap:BaseRateMembersrt:MinimumMember2024-03-310001508655Debt Investments Healthcare Merative L.P. First-lien loan ($70,103 par, due 6/2028) Initial Acquisition Date 6/30/2022 Reference Rate Spread SOFR + 7.25% Interest Rate 12.60%2023-12-310001508655us-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMember2023-01-012023-03-310001508655Debt Investments Business Services ExtraHop Networks, Inc. First-lien loan ($68,247 par, due 7/2027) Initial Acquisition Date 7/22/2021 Reference Rate and Spread SOFR + 7.60% Interest Rate 12.93%2024-03-310001508655tslx:SecondLienDebtInvestmentsMember2023-03-310001508655tslx:MezzanineDebtInvestmentsMember2024-03-310001508655country:FI2023-12-310001508655tslx:CrewlineBuyerIncMembertslx:RevolverEquityMember2024-03-310001508655Debt Investments Financial Services CLGF Holdco 2, LLC First-lien loan ($3,916 par, due 11/2027) Initial Acquisition Date 11/7/2023 Reference Rate and Spread SOFR + 8.50% Interest Rate 13.85%2023-12-310001508655Debt Investments Financial Services Ibis Intermediate Co. First-lien loan ($1,201 par, due 5/2027) Initial Acquisition Date 5/28/2021 Reference Rate and Spread SOFR + 4.65% Interest Rate 10.04%2023-12-310001508655Debt Investments Internet Services EDB Parent, LLC First-lien loan ($63,508 par, due 7/2028) Initial Acquisition Date 7/7/2022 Reference Rate and Spread SOFR + 6.75% Interest Rate 12.10%2023-01-012023-12-310001508655tslx:CommunicationsMember2023-12-310001508655Equity and Other Investments Healthcare Merative Topco L.P. 989,691 Class A-1 Units Initial Acquisition Date 6/30/20222024-01-012024-03-310001508655tslx:FutureRealizedCapitalGainsPriorToAprilFirstTwoThousandFourteenMembertslx:InvestmentAdvisoryAgreementMember2020-03-310001508655tslx:HirevueIncMembertslx:RevolverMember2023-12-310001508655Debt Investments Financial Services BlueSnap, Inc. First-lien loan ($41,790 par, due 10/2025) Initial Acquisition Date 10/25/2019 Reference Rate and Spread SOFR + 7.15% Interest Rate 12.46%2024-03-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. 106,592 Series D Warrants Initial Acquisition Date 4/8/20212024-03-310001508655Debt Investments Internet Services SMA Technologies Holdings, LLC First-lien loan ($36,833 par, due 10/2028) Initial Acquisition Date 10/31/2022 Reference Rate and Spread SOFR + 6.75% Interest Rate 12.11%2023-01-012023-12-310001508655us-gaap:AdditionalPaidInCapitalMember2023-12-310001508655Debt Investments Business Services Hornetsecurity Holding GmbH First-lien loan (EUR 3,150 par, due 11/2029) Initial Acquisition Date 11/14/2022 Reference Rate and Spread E + 6.50% Interest Rate 10.50%2023-01-012023-12-310001508655tslx:DelayedDrawMembertslx:EDBParentLLCMember2023-12-310001508655Debt Investments Automotive Truck-Lite Co., LLC First-lien revolving loan ($146 par, due 2/2030) Initial Acquisition Date 2/13/2024 Reference Rate and Spread SOFR + 5.75% Interest Rate 11.06%2024-03-310001508655Debt Investments Internet Services Arrow Buyer, Inc. First-lien loan ($35,209 par, due 7/2030) Initial Acquisition Date 6/30/2023 Reference Rate and Spread SOFR + 6.50% Interest Rate 11.80%2024-03-310001508655Debt Investments Human Resource Support Services PageUp People, Ltd. First-lien loan (GBP 2,761 par, due 12/2025) Initial Acquisition Date 10/28/2021 Reference Rate and Spread S + 5.03% Interest Rate 10.24%2024-03-310001508655tslx:DelayedDrawMembertslx:KangarooBidcoASMember2024-03-310001508655tslx:ControlledAffiliatedInvestmentsMember2024-01-012024-03-310001508655Equity and Other Investments Business Services Warrior TopCo LP Class A Units (423,729 units) Initial Acquisition Date 7/7/20232024-03-310001508655tslx:TwentyTwentySixNotesMember2024-01-012024-03-310001508655srt:MaximumMemberus-gaap:IncomeApproachValuationTechniqueMembertslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputDiscountRateMember2024-03-310001508655Equity and Other Investments Structured Credit Gulf Stream Meridian, Series 2021-6A Structured Product ($2,000par,due1/2037) Initial Acquisition Date 9/12/2022 Reference Rate and Spread SOFR+6.62% Interest Rate 11.93%2023-12-310001508655Equity and Other Investments Structured Credit Octagon 57 LLC, Series 2021-1A Structured Product ($1,000 par, due 10/2034) Initial Acquisition Date 5/24/2022 Reference Rate and Spread SOFR+ 6.86% Interest Rate 12.26%2023-01-012023-12-310001508655Equity and Other Investments Structured Credit Gulf Stream Meridian, Series 2021-6A Structured Product ($2,000par,due1/2037) Initial Acquisition Date 9/12/2022 Reference Rate and Spread SOFR+6.62% Interest Rate 11.94%2024-03-310001508655Equity and Other Investments Structured Credit Voya CLO Ltd, Series 2018-3A Structured Product ($2,750 par, due 10/2031) Initial Acquisition Date 6/22/2022 Reference Rate and Spread SOFR+ 6.01% Interest Rate 11.33%2024-03-310001508655us-gaap:FinancialServicesSectorMember2023-12-310001508655Equity and Other Investments Structured CreditAres Loan Funding I Ltd, Series 2021-ALFA, Class E Structured Product ($1,000 par,due 10/2034) Initial Acquisition Date 6/24/2022 Reference Rate and Spread SOFR+6.96% Interest Rate 12.36%2023-12-310001508655tslx:OfficeProductsMember2024-03-310001508655Debt Investments Financial Services Kyriba Corp. First-lien loan (EUR 10,924 par, due 4/2028) Initial Acquisition Date 12/21/2023 Reference Rate and Spread E + 8.50% Interest Rate 12.42% (incl. 8.50% PIK)2023-01-012023-12-310001508655us-gaap:TreasuryStockCommonMember2023-03-310001508655tslx:LeverageWaiverMembertslx:InvestmentAdvisoryAgreementMember2024-01-012024-03-310001508655Debt Investments Human Resource Support Services2023-12-310001508655tslx:AmericanAchievementCorpMembertslx:RevolverMember2024-03-310001508655tslx:KangarooBidcoASMembertslx:DelayedDrawMember2023-12-310001508655Equity and Other Investments Structured Credit Benefit Street Partners CLO Ltd, Series 2015-BR Structured Product ($2,500par,due7/2034) Initial Acquisition Date 7/13/2022 Reference Rate and Spread SOFR+4.11% Interest Rate 9.53%2023-01-012023-12-310001508655Debt Investments Business Services Price Fx Inc. First-lien loan (EUR 910 par, due 10/2029) Initial Acquisition Date 10/27/2023 Reference Rate and Spread E + 7.00% Interest Rate 10.94%2023-12-310001508655us-gaap:SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMembertslx:TwoThousandTwentyEightNotesMember2024-01-012024-03-310001508655Debt Investments Internet Services Lucidworks, Inc. First-lien loan ($8,912 par, due 2/2027) Initial Acquisition Date 2/11/2022 Reference Rate and Spread SOFR + 7.50% Interest Rate 12.86% (incl. 3.50% PIK)2023-01-012023-12-310001508655Debt Investments Internet Services LeanTaaS Holdings, Inc. First-lien loan ($39,426 par, due 7/2028) Initial Acquisition Date 7/12/2022 Reference Rate and Spread SOFR + 7.50% Interest Rate 12.81%2024-01-012024-03-310001508655Debt Investments Oil, Gas and Consumable Fuels Laramie Energy, LLC First-lien loan ($27,317 par, due 2/2027) Initial Acquisition Date 2/21/2023 Reference Rate and Spread SOFR + 7.10% Interest Rate 12.43%2024-01-012024-03-310001508655tslx:TwoThousandTwentyFourNotesMemberus-gaap:SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember2023-01-012023-12-310001508655tslx:InsuranceMember2024-03-310001508655Debt Investments Human Resource Support Services HireVue, Inc. First-lien loan ($54,113 par, due 5/2029) Initial Acquisition Date 5/3/2023 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.63%2023-01-012023-12-310001508655Debt Investments, Manufacturing, ASP Unifrax Holdings, Inc, Unsecured Note ($1,059 par, due 9/2029), Initial Acquisition Date 8/31/2023, Reference Rate and Spread, 7.50%, Interest Rate 7.50%2024-01-012024-03-310001508655tslx:DelayedDrawMembertslx:Project44IncMember2023-12-310001508655tslx:TwoThousandTwentyEightNotesMember2023-12-310001508655tslx:FirstLienDebtInvestmentsMember2023-01-012023-12-310001508655Equity and Other Investments Structured Credit KKR CLO Ltd, 49A Structured Product ($1,000 par, due 7/2035) Initial Acquisition Date 6/2/2022 Reference Rate and Spread SOFR+ 8.26% Interest Rate 13.42%2023-12-310001508655tslx:RevolvingCreditFacilityMaturityOnApril232027Member2024-04-242024-04-240001508655tslx:BlackScholesModelMembertslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Member2023-12-310001508655Debt Investments Retail and Consumer Products Rapid Data GmbH Unternehmensberatung First-lien loan (EUR 4,495 par, due 7/2029) Initial Acquisition Date 7/11/2023 Reference Rate and Spread E + 6.50% Interest Rate 10.48%2023-12-310001508655Equity and Other Investments Structured Credit Wind River CLO Ltd, Series 2014-2A Structured Product ($1,500par,due 1/2031) Initial Acquisition Date 6/23/2022 Reference Rate and Spread SOFR+ 3.16% Interest Rate 8.56%2023-12-310001508655Debt Investments Healthcare Edge Bidco B.V First-lien loan (EUR 5,811 par, due 2/2029) Initial Acquisition Date 2/24/2023 Reference Rate and Spread E + 7.00% Interest Rate 10.93% (incl. 3.25% PIK)2024-03-310001508655Equity and Other Investments Business Services Artisan Topco LP Class A Preferred Units (2,117,264 units) Initial Acquisition Date 11/7/20232024-01-012024-03-310001508655Debt Investments Internet Services Lithium Technologies, LLC First-lien loan ($58,342 par, due 1/2025) Initial Acquisition Date 10/3/2017 Reference Rate and Spread SOFR + 9.00% Interest Rate 14.32% (incl. 4.50% PIK)2024-03-310001508655Equity and Other Investments Financial Services TradingScreen, Inc. Class A Units (600,000 units) Initial Acquisition Date 5/14/20212024-01-012024-03-310001508655Debt Investments Healthcare Merative L.P. First-lien loan ($70,103 par, due 6/2028) Initial Acquisition Date 6/30/2022 Reference Rate Spread SOFR + 7.25% Interest Rate 12.60%2023-01-012023-12-310001508655Equity and Other Investments Internet Services Bayshore Intermediate #2, L.P. Co-Invest 2 Common Units (3,493,701 units) Initial Acquisition Date 10/1/20212023-12-310001508655Debt Investments Chemicals2024-03-310001508655Equity and Other Investments Internet Services Piano Software, Inc. Series C-2 Preferred Shares (27,588 shares) Initial Acquisition Date 11/18/20222024-03-310001508655Equity and Other Investments2023-12-310001508655Equity and Other Investments Business Services ReliaQuest, LLC Series A Preferred Stock (1,748 units) Initial Acquisition Date 12/20/2023 Reference Rate and Spread SOFR+12.00% Interest Rate 17.37% PIK2024-03-310001508655Equity and Other Investments Structured Credit RR Ltd, Series 2020-8A Structured Product ($1,000par,due4/2033) Initial Acquisition Date 8/22/2022 Reference Rate and Spread SOFR+6.66% Interest Rate 12.06%2023-01-012023-12-310001508655tslx:TwoThousandTwentyFourNotesMemberus-gaap:SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember2024-01-012024-03-310001508655tslx:DelayedDrawEquityMembertslx:TRPAssetsLLCMember2023-12-310001508655Debt Investments Oil, Gas and Consumable Fuels TRP Assets, LLC First-lien loan ($65,000 par, due 12/2025) Initial Acquisition Date 12/3/2021 Reference Rate and Spread SOFR + 7.76% Interest Rate 13.07%2024-03-310001508655srt:MaximumMemberus-gaap:IncomeApproachValuationTechniqueMembertslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputDiscountRateMember2023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:EmploymentHeroHoldingsPtyLtdMember2024-03-310001508655Interest Rate Swap Company Pays SOFR + 2.99% Maturity Date 8/14/20282023-12-310001508655Equity and Other Investments Financial Services Oxford Square Capital Corp. Common Shares (1,620 shares) Initial Acquisition Date 8/5/20152024-03-310001508655tslx:TwoThousandTwentyFourNotesMember2024-03-310001508655Debt Investments Manufacturing ASP Unifrax Holdings, Inc. First-lien loan (EUR 1,023 par, due 12/2025) Initial Acquisition Date 9/14/2023 Reference Rate and Spread E + 3.75% Interest Rate 7.68%2023-12-310001508655Debt Investments Chemicals Erling Lux Bidco SARL First-lien loan (EUR 7,239 par, due 9/2028) Initial Acquisition Date 9/6/2022 Reference Rate and Spread E + 6.75% Interest Rate 10.64%2024-01-012024-03-310001508655Debt Investments Internet Services Higher Logic, LLC First-lien loan ($52,937 par, due 1/2025) Initial Acquisition Date 6/18/2018 Reference Rate and Spread SOFR + 6.75% Interest Rate 12.10%2023-12-310001508655Equity and Other Investments Internet Services Bayshore Intermediate #2, L.P. Co-Invest 2 Common Units (3,493,701 units) Initial Acquisition Date 10/1/20212024-01-012024-03-310001508655Debt Investments Hotel, Gaming and Leisure ASG II, LLC First-lien loan ($61,609 par, due 5/2028) Initial Acquisition Date 5/25/2022 Reference Rate and Spread SOFR + 6.40% Interest Rate 11.77%2023-01-012023-12-310001508655Equity and Other Investments Oil, Gas and Consumable Fuels TRP Assets, LLC Partnership Interest (1.89% ownership) Initial Acquisition Date 8/25/20222023-01-012023-12-310001508655Equity and Other Investments Structured Credit CIFC CLO Ltd, Series 2018-3A Structured Product ($1,000par,due7/2031)Initial Acquisition Date 6/16/2022 Reference Rate and Spread SOFR+5.76% Interest Rate 11.06%2024-03-310001508655tslx:RevolverMembertslx:DiscoParentIncMember2023-12-310001508655Equity and Other Investments Structured Credit Ares CLO Ltd, Series 2021-59A Structured Product ($1,000par,due4/2034) Initial Acquisition Date 6/23/2022 Reference Rate and Spread SOFR+6.51% Interest Rate 11.84%2024-01-012024-03-310001508655Equity and Other Investments Healthcare2023-12-310001508655Debt Investments Transportation Project44, Inc. First-lien loan ($35,139 par, due 11/2027) Initial Acquisition Date 11/12/2021 Reference Rate and Spread SOFR + 6.40% Interest Rate 11.78%2023-12-310001508655Debt Investments Communications IntelePeer Holdings, Inc. First-lien loan ($33,646 par, due 12/2024) Initial Acquisition Date 12/2/2019 Reference Rate and Spread SOFR + 8.40% Interest Rate 13.75%2023-01-012023-12-310001508655Debt Investments Financial Services2023-12-310001508655us-gaap:DomesticCountryMember2024-01-012024-03-310001508655Equity and Other Investments Internet Services Lucidworks, Inc. Series F Preferred Shares (199,054 shares) Initial Acquisition Date 8/2/20192024-03-310001508655Debt Investments Oil, Gas and Consumable Fuels Mach Natural Resources LP First-lien loan ($5,000 par, due 12/2026) Initial Acquisition Date 12/28/2023 Reference Rate and Spread SOFR + 6.65% Interest Rate 12.00%2023-01-012023-12-310001508655tslx:DelayedDrawMembertslx:BctoBluebillBuyerIncMember2023-12-310001508655Debt Investments Manufacturing ASP Unifrax Holdings, Inc. First-lien loan ($1,130 par, due 12/2025) Initial Acquisition Date 8/25/2023 Reference Rate and Spread SOFR + 3.90% Interest Rate 9.25%2023-01-012023-12-310001508655tslx:MezzanineDebtInvestmentsMemberus-gaap:FairValueInputsLevel2Member2023-12-310001508655Debt Investments Financial Services CLGF Holdco 2, LLC First-lien loan ($3,916 par, due 11/2027) Initial Acquisition Date 11/7/2023 Reference Rate and Spread SOFR + 8.50% Interest Rate 13.81%2024-01-012024-03-310001508655Debt Investments Financial Services Volante Technologies, Inc. First-lien loan ($2,604 par, due 9/2028) Initial Acquisition Date 9/29/2023 Reference Rate and Spread 16.50% Interest Rate 16.50% PIK2023-12-310001508655Debt Investments Financial Services BCTO Bluebill Buyer, Inc. First-lien loan ($28,640 par, due 7/2029) Initial Acquisition Date 7/20/2023 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.60%2024-01-012024-03-310001508655Debt Investments Retail and Consumer Products Tango Management Consulting, LLC First-lien loan ($57,007 par, due 12/2027) Initial Acquisition Date 12/1/2021 Reference Rate and Spread SOFR + 6.85% Interest Rate 12.20%2023-12-310001508655Debt Investments Automotive Bestpass, Inc. First-lien loan ($44,688 par, due 5/2029) Initial Acquisition Date 5/26/2023 Reference Rate and Spread SOFR + 5.75% Interest Rate 11.08%2024-03-310001508655Equity and Other Investments Retail and Consumer Products Copper Bidco, LLC Trust Certificates (132,928 Certificates) Initial Acquisition Date 12/7/20202023-01-012023-12-310001508655Equity and Other Investments Structured Credit Octagon Investment Partners 38 Ltd, Series 2018-1A Structured Product ($2,800 par, due 7/2030) Initial Acquisition Date 9/20/2022 Reference Rate and Spread SOFR+ 3.21% Interest Rate 8.63%2023-12-310001508655Equity and Other Investments Education EMS Linq, Inc. Class B Units (5,522,526 units) Initial Acquisition Date 12/22/20212023-01-012023-12-310001508655tslx:EquityAndOtherInvestmentsMember2022-12-310001508655Equity and Other Investments Structured Credit Jefferson Mill CLO Ltd, Series 2015-1A Structured Product ($1,000par,due 10/2031) Initial Acquisition Date 5/23/2022 Reference Rate and Spread SOFR+ 3.81% Interest Rate 9.22%2023-01-012023-12-310001508655tslx:MidwestMember2024-03-310001508655Equity and Other Investments Structured Credit Eaton CLO Ltd, Series 2015-1A Structured Product ($2,500par,due1/2030) Initial Acquisition Date 6/23/2022 Reference Rate and Spread SOFR+2.76% Interest Rate 8.18%2023-01-012023-12-310001508655Debt Investments Manufacturing Avalara, Inc. First-lien loan ($38,636 par, due 10/2028) Initial Acquisition Date 10/19/2022 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.60%2023-01-012023-12-310001508655us-gaap:AssetPledgedAsCollateralMember2023-12-310001508655tslx:InterestRateSwapFourMember2023-01-012023-03-310001508655Equity and Other Investments Structured Credit MidOcean Credit CLO Ltd, Series 2016-6A Structured Product ($3,500 par, due 4/2033) Initial Acquisition Date 5/23/2022 Reference Rate and Spread SOFR+ 3.78% Interest Rate 9.20%2023-01-012023-12-310001508655tslx:LeantaasHoldingsIncMembertslx:DelayedDrawMember2024-03-310001508655Debt Investments Retail and Consumer Products Neuintel, LLC First-lien loan ($57,701 par, due 12/2026) Initial Acquisition Date 12/20/2021 Reference Rate and Spread SOFR + 7.65% Interest Rate 13.03%2023-12-310001508655Debt Investments Automotive2024-03-310001508655country:NO2023-12-310001508655tslx:InterestRateSwapTwoMember2023-01-012023-03-310001508655us-gaap:RevolvingCreditFacilityMembersrt:MinimumMember2024-01-012024-03-310001508655Debt Investments Communications Celtra Technologies, Inc. First-lien loan ($34,038 par, due 11/2026) Initial Acquisition Date 11/19/2021 Reference Rate and Spread SOFR + 6.35% Interest Rate 11.71%2023-01-012023-12-310001508655Equity and Other Investments Education Astra 2L Holdings II LLC Membership Interest (10.17% ownership) Initial Acquisition Date 1/13/20222023-12-310001508655Debt Investments Manufacturing Aptean, Inc First-lien loan ($7,922 par, due 1/2031) Initial Acquisition Date 1/30/2024 Reference Rate and Spread SOFR + 5.25% Interest Rate 10.57%2024-03-310001508655Equity and Other Investments Human Resource Support Services2023-12-310001508655Equity and Other Investments Structured Credit Dryden Senior Loan Fund, Series 2018-55A Structured Product ($1,000par,due4/2031)Initial Acquisition Date 7/25/2022 Reference Rate and Spread SOFR+3.11% Interest Rate 8.51%2023-01-012023-12-310001508655Debt Investments Business Services Galileo Parent, Inc. First-lien revolving loan ($4,471 par, due 5/2030) Initial Acquisition Date 5/3/2023 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.56%2024-03-310001508655Debt Investments Financial Services Kyriba Corp. First-lien loan ($35,634 par, due 4/2028) Initial Acquisition Date 12/21/2023 Reference Rate and Spread SOFR + 8.50% Interest Rate 13.87% (incl. 8.50% PIK)2023-01-012023-12-310001508655Debt Investments Business Services Mitnick Corporate Purchaser, Inc First-lien loan ($329 par, due 5/2029) Initial Acquisition Date 5/2/2022 Reference Rate and Spread SOFR + 4.50% Interest Rate 9.98%2023-12-310001508655Debt Investments Retail and Consumer Products Bed Bath and Beyond Inc. Roll Up DIP term loan ($25,931 par, due 9/2024) Initial Acquisition Date 4/24/2023 Reference Rate and Spread SOFR + 7.90% Interest Rate 13.26% (incl. 13.26% PIK)2023-12-310001508655Equity and Other Investments Structured Credit Gulf Stream Meridian, Series 2021-4A Structured Product ($1,015par,due7/2034) Initial Acquisition Date 6/3/2022 Reference Rate and Spread SOFR+6.61% Interest Rate 12.01%2023-12-310001508655us-gaap:FairValueInputsLevel3Membertslx:SecondLienDebtInvestmentsMember2023-01-012023-03-310001508655us-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMember2024-01-012024-03-310001508655tslx:HirevueIncMembertslx:RevolverMember2024-03-310001508655Interest Rate Swap Company Pays SOFR + 2.72% Maturity Date 11/1/20242024-03-310001508655Equity and Other Investments Education RMCF IV CIV XXXV, LP. Partnership Interest (11.94% ownership) Initial Acquisition Date 6/8/20212023-01-012023-12-310001508655Equity and Other Investments Structured Credit Wind River CLO Ltd, Series 2017-1A Structured Product ($3,000par, due 4/2036) Initial Acquisition Date 7/14/2022 Reference Rate and Spread SOFR+ 3.98% Interest Rate 9.38%2023-01-012023-12-310001508655tslx:RetailAndConsumerProductsMember2023-12-310001508655Equity and Other Investments Structured Credit Madison Park CLO, Series 2018-28A Structured Product ($1,000 par, due 7/2030) Initial Acquisition Date 6/28/2022 Reference Rate and Spread SOFR+ 5.51% Interest Rate 10.91%2023-12-310001508655Equity and Other Investments Structured Credit Octagon Investment Partners 18 Ltd, Series 2018 – 18A Structured Product ($1,000 par, due 4/2031) Initial Acquisition Date 7/26/2022 Reference Rate and Spread SOFR+ 2.96% Interest Rate 8.36%2023-01-012023-12-310001508655Equity and Other Investments Hotel, Gaming and Leisure2023-12-310001508655Equity and Other Investments Business Services Mitnick TA Aggregator, L.P. Membership Interest (0.43% ownership) Initial Acquisition Date 5/2/20222024-03-310001508655tslx:AssetValuationWaterfallMemberus-gaap:FairValueInputsLevel3Membertslx:SecondLienDebtInvestmentsMember2023-12-310001508655tslx:WestMember2023-12-310001508655Equity and Other Investments Business Services Sprinklr, Inc. Common Shares (315,005 shares) Initial Acquisition Date 6/24/20212023-01-012023-12-310001508655Derivative Interest Rate Swap2023-01-012023-12-310001508655Debt Investments Oil, Gas and Consumable Fuels TRP Assets, LLC First-lien loan ($65,000 par, due 12/2025) Initial Acquisition Date 12/3/2021 Reference Rate and Spread SOFR + 7.76% Interest Rate 13.11%2023-12-310001508655Debt Investments Internet Services Higher Logic, LLC First-lien loan ($52,216 par, due 1/2025) Initial Acquisition Date 6/18/2018 Reference Rate and Spread SOFR + 6.25% Interest Rate 11.56%2024-01-012024-03-310001508655tslx:TwentyTwentyThreeNotesMember2018-01-012018-01-310001508655tslx:TwoThousandTwentySixNotesMember2024-01-012024-03-310001508655tslx:TransportationMember2024-03-310001508655us-gaap:UnfundedLoanCommitmentMember2024-03-3100015086552023-05-152023-05-150001508655Debt Investments Internet Services Bayshore Intermediate #2, L.P. First-lien loan ($36,629 par, due 10/2028) Initial Acquisition Date 10/1/2021 Reference Rate and Spread SOFR + 7.60% Interest Rate 12.96% PIK2023-01-012023-12-310001508655tslx:SecondLienDebtInvestmentsMember2023-12-310001508655tslx:RealizedCapitalGainsAccruedBeginningAprilFirstTwoThousandFourteenMembertslx:InvestmentAdvisoryAgreementMember2011-04-152011-04-150001508655Debt Investments Business Services ExtraHop Networks, Inc. First-lien loan ($66,197 par, due 7/2027) Initial Acquisition Date 7/22/2021 Reference Rate and Spread SOFR + 7.60% Interest Rate 12.96%2023-12-310001508655Debt Investments Retail and Consumer Products PDI TA Holdings, Inc. First-lien loan ($14,410 par, due 2/2031) Initial Acquisition Date 2/1/2024 Reference Rate and Spread SOFR +5.50% Interest Rate 10.83%2024-01-012024-03-310001508655Hedge Accounting Swaps2024-03-310001508655Debt Investments Other Omnigo Software, LLC First-lien loan ($39,943 par, due 3/2026) Initial Acquisition Date 3/31/2021 Reference Rate and Spread SOFR + 6.60% Interest Rate 11.96%2023-01-012023-12-310001508655Equity and Other Investments Internet Services Lucidworks, Inc. Series F Preferred Shares (199,054 shares) Initial Acquisition Date 8/2/20192024-01-012024-03-310001508655Debt Investments Human Resource Support Services Employment Hero Holdings Pty Ltd. First-lien loan (AUD 50,000 par, due 12/2026) Initial Acquisition Date 12/6/2021 Reference Rate and Spread B + 6.25% Interest Rate 10.67%2023-01-012023-12-310001508655Equity and Other Investments Structured Credit Eaton CLO Ltd, Series 2020-1A Structured Product ($1,000par,due10/2034) Initial Acquisition Date 8/11/2022 Reference Rate and Spread SOFR+6.51% Interest Rate 11.91%2023-01-012023-12-310001508655tslx:DelayedDrawMembertslx:IbisIntermediateCoMember2023-12-3100015086552024-03-050001508655Debt Investments Business Services ReliaQuest Holdings, LLC First-lien loan ($82,626 par, due 10/2026) Initial Acquisition Date 10/8/2020 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.63%2023-01-012023-12-310001508655Debt Investments Human Resource Support Services PrimePay Intermediate, LLC First-lien loan ($34,287 par, due 12/2026) Initial Acquisition Date 12/17/2021 Reference Rate and Spread SOFR + 7.15% Interest Rate 12.46%2024-01-012024-03-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. Series D Preferred Shares (1,240,740 shares) Initial Acquisition Date 5/11/20212024-03-310001508655tslx:TwoThousandTwentyFourNotesMember2020-12-310001508655srt:MaximumMemberus-gaap:IncomeApproachValuationTechniqueMembertslx:MezzanineDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputDiscountRateMember2023-12-310001508655Equity and Other Investments Structured Credit Wind River CLO Ltd, Series 2014-2A Structured Product ($1,500par,due 1/2031) Initial Acquisition Date 6/23/2022 Reference Rate and Spread SOFR+ 3.16% Interest Rate 8.48%2024-01-012024-03-310001508655Equity and Other Investments Structured Credit Carlyle Global Market Strategies CLO Ltd, Series 2016-1, Ltd Structured Product ($1,600par,due4/2034) Initial Acquisition Date 2/15/2023 Reference Rate and Spread SOFR+6.86% Interest Rate 12.18%2024-03-310001508655tslx:TwentyTwentyEightNotesMember2023-08-142023-08-140001508655tslx:DelayedDrawMembertslx:SkylarkUkDebtcoLimitedMember2023-12-310001508655tslx:HumanResourceSupportServicesMember2023-12-310001508655us-gaap:InterestRateSwapMember2024-03-310001508655tslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputComparabilityAdjustmentMemberus-gaap:MarketApproachValuationTechniqueMember2024-03-310001508655Debt Investments Healthcare Raptor US Buyer II Corp. First-lien loan ($15,530 par,due3/2029) Initial Acquisition Date 3/24/2023 Reference Rate and Spread SOFR + 6.75% Interest Rate 12.06%2024-01-012024-03-310001508655Derivative Interest Rate Swap2024-01-012024-03-310001508655Equity and Other Investments Structured Credit Ares CLO Ltd, Series 2021-59A Structured Product ($1,000par,due4/2034) Initial Acquisition Date 6/23/2022 Reference Rate and Spread SOFR+6.51% Interest Rate 11.89%2023-01-012023-12-310001508655Equity and Other Investments Structured Credit Gulf Stream Meridian, Series 2021-4A Structured Product ($1,015par,due7/2034) Initial Acquisition Date 6/3/2022 Reference Rate and Spread SOFR+6.61% Interest Rate 11.93%2024-03-310001508655Debt Investments Financial Services Passport Labs, Inc. First-lien loan ($24,857 par, due 4/2026) Initial Acquisition Date 4/28/2021 Reference Rate and Spread SOFR + 7.25% Interest Rate 15.75%2024-01-012024-03-310001508655Interest Rate Swap Company Receives SOFR + 2.54% Maturity Date 11/1/20242023-01-012023-12-310001508655Debt Investments Internet Services Arrow Buyer, Inc. First-lien loan ($35,209 par, due 7/2030) Initial Acquisition Date 6/30/2023 Reference Rate and Spread SOFR + 6.50% Interest Rate 11.80%2024-01-012024-03-310001508655us-gaap:RevolvingCreditFacilityMembersrt:ObligorGroupMembersrt:MinimumMember2024-03-310001508655Debt Investments Financial Services2024-03-310001508655tslx:InterestRateSwapOneMember2024-01-012024-03-310001508655tslx:SouthMember2023-12-310001508655Debt Investments Financial Services Alaska Bidco Oy First-lien loan (EUR 727 par, due 5/2030) Initial Acquisition Date 5/30/2023 Reference Rate and Spread E + 6.25% Interest Rate 10.15%2024-01-012024-03-310001508655Equity and Other Investments Pharmaceuticals TherapeuticsMD, Inc. 14,256 Warrants Initial Acquisition Date 8/5/20202023-12-310001508655Equity and Other Investments Structured Credit Carlyle Global Market Strategies CLO Ltd, Series 2014-4RA Structured Product ($1,000par,due7/2030) Initial Acquisition Date 5/26/2022 Reference Rate and Spread SOFR+3.16% Interest Rate 8.48%2024-01-012024-03-310001508655Equity and Other Investments Communications2024-03-310001508655tslx:AssetValuationWaterfallMemberus-gaap:FairValueInputsLevel3Membertslx:SecondLienDebtInvestmentsMember2024-03-310001508655Debt Investments Financial Services Fullsteam Operations LLC First-lien loan ($33,479 par, due 11/2029) Initial Acquisition Date 11/27/2023 Reference Rate and Spread SOFR + 8.40% Interest Rate 13.73%2024-01-012024-03-310001508655Debt Investments Business Services Artisan Bidco, Inc First-lien loan ($38,112 par, due 11/2029) Initial Acquisition Date 11/7/2023 Reference Rate and Spread SOFR + 7.00% Interest Rate 12.38%2023-12-310001508655us-gaap:RetainedEarningsMember2023-12-310001508655Equity and Other Investments Human Resource Support Services bswift, LLC Class A-1 Units (2,393,509 units) Initial Acquisition Date 11/7/20222024-01-012024-03-310001508655country:CA2024-03-310001508655Debt Investments Hotel, Gaming and Leisure IRGSE Holding Corp. First-lien revolving loan ($27,622 par, due 6/2024) Initial Acquisition Date 12/21/2018 Reference Rate and Spread SOFR + 9.65% Interest Rate 15.03%2023-01-012023-12-310001508655Total Investments2023-12-310001508655Debt Investments Chemicals Erling Lux Bidco SARL First-lien loan (GBP 13,388 par, due 9/2028) Initial Acquisition Date 9/6/2022 Reference Rate and Spread S + 6.75% Interest Rate 11.94%2024-03-310001508655tslx:EquityAndOtherInvestmentsMember2024-03-310001508655Debt Investments Financial Services Passport Labs, Inc. First-lien loan ($24,603 par, due 4/2026) Initial Acquisition Date 4/28/2021 Reference Rate and Spread SOFR + 8.40% Interest Rate 13.75%2023-01-012023-12-310001508655Debt Investments Internet Services Piano Software, Inc. First-lien loan ($50,889 par, due 2/2026) Initial Acquisition Date 2/25/2021 Reference Rate and Spread SOFR + 7.10% Interest Rate 12.45%2023-01-012023-12-310001508655Interest Rate Swap Company Receives 6.95% Company Pays SOFR + 2.99% Maturity Date 8/14/20282023-01-012023-12-310001508655tslx:DelayedDrawEquityMembertslx:ReliaQuestHoldingsLLCMember2024-03-310001508655Debt Investments Automotive Truck-Lite Co., LLC First-lien revolving loan ($146 par, due 2/2030) Initial Acquisition Date 2/13/2024 Reference Rate and Spread SOFR + 5.75% Interest Rate 11.06%2024-01-012024-03-310001508655Debt Investments Financial Services BTRS Holdings, Inc. First-lien revolving loan ($1,205 par, due 12/2028) Initial Acquisition Date 12/16/2022 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.63%2023-12-310001508655Debt Investments Retail and Consumer Products 99 Cents Only Stores LLC ABL FILO term loan ($25,000 par, due 5/2025) Initial Acquisition Date 9/6/2017 Reference Rate and Spread SOFR + 8.65% Interest Rate 14.03%2023-01-012023-12-310001508655Debt Investments Business Services Crewline Buyer, Inc. First-lien loan ($56,324 par, due 11/2030) Initial Acquisition Date 11/8/2023 Reference Rate and Spread SOFR + 6.75% Interest Rate 12.06%2024-03-310001508655Debt Investments Internet Services Hippo XPA Bidco AB First-lien loan (SEK 78,125 par, due 2/2031) Initial Acquisition Date 2/20/2024 Reference Rate and Spread STIBOR + 6.50% Interest Rate 10.58% (incl. 3.50% PIK)2024-03-310001508655Equity and Other Investments Retail and Consumer Products Neuintel, LLC Class A Units (1,176,494 units) Initial Acquisition Date 12/21/20212023-01-012023-12-310001508655Debt Investments Hotel, Gaming and Leisure ASG II, LLC First-lien loan ($61,609 par, due 5/2028) Initial Acquisition Date 5/25/2022 Reference Rate and Spread SOFR + 6.40% Interest Rate 11.77%2023-12-310001508655Debt Investments Education Astra Acquisition Corp. Second-lien loan ($43,479 par, due 10/2029) Initial Acquisition Date 10/22/2021 Reference Rate and Spread SOFR + 9.14% Interest Rate 14.48%2023-01-012023-12-310001508655Hedge Accounting Swaps2023-12-310001508655Equity and Other Investments Structured Credit Octagon Investment Partners 18 Ltd, Series 2018 – 18A Structured Product ($1,000 par, due 4/2031) Initial Acquisition Date 7/26/2022 Reference Rate and Spread SOFR+ 2.96% Interest Rate 8.28%2024-03-310001508655Debt Investments Oil, Gas and Consumable Fuels TRP Assets, LLC First-lien loan ($65,000 par, due 12/2025) Initial Acquisition Date 12/3/2021 Reference Rate and Spread SOFR + 7.76% Interest Rate 13.07%2024-01-012024-03-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. 569,991 Warrants Initial Acquisition Date 4/2/20202024-03-310001508655Debt Investments Other Omnigo Software, LLC First-lien loan ($39,840 par, due 3/2026) Initial Acquisition Date 3/31/2021 Reference Rate and Spread SOFR + 6.60% Interest Rate 11.93%2024-01-012024-03-310001508655tslx:OtherMember2024-03-310001508655tslx:TwoThousandTwentyFourNotesMember2019-11-012019-11-300001508655Debt Investments Retail and Consumer Products Bed Bath and Beyond Inc. ABL FILO term loan ($14,065 par, due 8/2027) Initial Acquisition Date 9/2/2022 Reference Rate and Spread SOFR + 9.90% Interest Rate 15.26%2023-01-012023-12-310001508655Equity and Other Investments Structured Credit Park Avenue Institutional Advisers CLO Ltd, Series 2018-1A Structured Product ($1,000 par,due 10/2031) Initial Acquisition Date 9/23/2022 Reference Rate and Spread SOFR+ 3.59% Interest Rate 8.91%2024-01-012024-03-310001508655Equity and Other Investments Structured Credit Gulf Stream Meridian, Series 2021-6A Structured Product ($2,000par,due1/2037) Initial Acquisition Date 9/12/2022 Reference Rate and Spread SOFR+6.62% Interest Rate 11.94%2024-01-012024-03-310001508655Debt Investments Business Services Galileo Parent, Inc. First-lien loan ($64,742 par, due 5/2030) Initial Acquisition Date 5/3/2023 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.60%2023-12-310001508655us-gaap:InvestmentAffiliatedIssuerControlledMember2023-01-012023-12-310001508655Debt Investments Communications IntelePeer Holdings, Inc. First-lien loan ($33,367 par, due 12/2024) Initial Acquisition Date 12/2/2019 Reference Rate and Spread SOFR + 8.40% Interest Rate 13.71%2024-03-310001508655Equity and Other Investments Structured Credit GoldenTree CLO Ltd, Series 2020-7A Structured Product ($1,000par,due4/2034) Initial Acquisition Date 6/17/2022 Reference Rate and Spread SOFR+6.76% Interest Rate 12.18%2023-12-310001508655Debt Investments Healthcare BCTO Ace Purchaser, Inc. First-lien loan ($69,231 par, due 11/2027) Initial Acquisition Date 11/23/2020 Reference Rate and Spread SOFR + 7.45% Interest Rate 12.84%2023-01-012023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:EdgeBidcoBVMember2024-03-310001508655Equity and Other Investments Education Astra 2L Holdings II LLC Membership Interest (10.17% ownership) Initial Acquisition Date 1/13/20222024-03-310001508655Debt Investments Transportation Marcura Equities LTD First-lien revolving loan ($1,667 par, due 8/2029) Initial Acquisition Date 8/11/2023 Reference Rate and Spread SOFR + 7.00% Interest Rate 12.18%2024-01-012024-03-310001508655Interest Rate Swap Company Receives 6.95% Company Pays SOFR + 2.99% Maturity Date 8/14/20282024-03-310001508655Interest Rate Swap Company Pays 3.875% Maturity Date 11/1/20242024-03-310001508655Equity and Other Investments Internet Services SMA Technologies Holdings, LLC Class A Units (1,300 shares) Initial Acquisition Date 11/21/20222023-01-012023-12-310001508655Equity and Other Investments Structured Credit Park Avenue Institutional Advisers CLO Ltd, Series 2018-1A Structured Product ($1,000 par,due 10/2031) Initial Acquisition Date 9/23/2022 Reference Rate and Spread SOFR+ 3.59% Interest Rate 9.01%2023-12-310001508655us-gaap:FairValueInputsLevel3Membertslx:SecondLienDebtInvestmentsMember2023-12-310001508655Equity and Other Investments Business Services Mitnick TA Aggregator, L.P. Membership Interest (0.43% ownership) Initial Acquisition Date 5/2/20222023-12-310001508655tslx:OfficeProductsMember2023-12-310001508655Debt Investments Financial Services Kyriba Corp. First-lien loan ($36,399 par, due 4/2028) Initial Acquisition Date 12/21/2023 Reference Rate and Spread SOFR + 8.50% Interest Rate 13.83% (incl. 8.50% PIK)2024-03-310001508655Equity and Other Investments Structured Credit Cedar Funding CLO Ltd, Series 2018-7A Structured Product ($1,000par,due1/2031) Initial Acquisition Date 7/21/2022 Reference Rate and Spread SOFR+4.81% Interest Rate 10.13%2024-01-012024-03-310001508655Debt Investments Human Resource Support Services HireVue, Inc. First-lien loan ($53,978 par, due 5/2029) Initial Acquisition Date 5/3/2023 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.56%2024-03-310001508655Debt Investments Financial Services Ping Identity Holding Corp. First-lien loan ($22,727 par, due 10/2029) Initial Acquisition Date 10/17/2022 Reference Rate and Spread SOFR + 7.00% Interest Rate 12.33%2024-01-012024-03-310001508655Interest Rate Swap Company Receives 3.875% Company Pays SOFR + 2.72% Maturity Date 11/1/20242023-01-012023-12-310001508655Debt Investments Insurance Disco Parent, Inc. First-lien loan ($4,545 par, due 3/2029) Initial Acquisition Date 3/30/2023 Reference Rate and Spread SOFR + 7.50% Interest Rate 12.89%2023-12-310001508655Debt Investments Healthcare BCTO Ace Purchaser, Inc. Second-lien loan ($5,623 par, due 1/2030) Initial Acquisition Date 1/23/2023 Reference Rate and Spread SOFR + 10.70% Interest Rate 16.10%2023-01-012023-12-310001508655us-gaap:RetainedEarningsMember2024-03-310001508655tslx:BaseDividendMember2023-02-160001508655srt:MaximumMembertslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputComparabilityAdjustmentMemberus-gaap:MarketApproachValuationTechniqueMember2024-03-310001508655Equity and Other Investments Structured Credit Southwick Park CLO Ltd, Series 2019-4A Structured Product ($1,000 par,due 7/2032) Initial Acquisition Date 5/25/2022 Reference Rate and Spread SOFR+ 6.51% Interest Rate 11.93%2023-01-012023-12-310001508655Debt Investments Financial Services BlueSnap, Inc. First-lien loan ($41,895 par, due 10/2025) Initial Acquisition Date 10/25/2019 Reference Rate and Spread SOFR + 7.15% Interest Rate 12.50%2023-01-012023-12-310001508655Equity and Other Investments Marketing Services Validity, Inc. Series A Preferred Shares (3,840,000 shares) Initial Acquisition Date 5/31/20182023-12-310001508655Debt Investments Financial Services Passport Labs, Inc. Convertible Promissory Note A ($1,086 par, due 8/2026) Initial Acquisition Date 3/2/2023 Reference Rate and Spread 8.00% Interest Rate 8.00%2023-01-012023-12-310001508655Equity and Other Investments Communications Celtra Technologies, Inc. Class A Units (1,250,000 units) Initial Acquisition Date 11/19/20212024-01-012024-03-310001508655Equity and Other Investments Education2023-12-310001508655Equity and Other Investments Financial Services AF Eagle Parent, L.P. Partnership (121,329 units) Initial Acquisition Date 11/27/20232024-03-310001508655Debt Investments Financial Services BCTO Bluebill Buyer, Inc. First-lien loan ($28,640 par, due 7/2029) Initial Acquisition Date 7/20/2023 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.60%2024-03-310001508655Debt Investments Transportation Ben Nevis Midco Limited First-lien loan ($3,296 par, due 3/2028) Initial Acquisition Date 3/26/2024 Reference Rate and Spread SOFR + 5.00% Interest Rate 10.31%2024-01-012024-03-310001508655Debt Investments Business Services Netwrix Corp. First-lien loan ($36,594 par, due 6/2029) Initial Acquisition Date 5/9/2022 Reference Rate and Spread SOFR + 5.00% Interest Rate 10.39%2023-01-012023-12-310001508655tslx:RevolverEquityMembertslx:CrewlineBuyerIncMember2023-12-310001508655Equity and Other Investments Business Services Warrior TopCo LP Class A Units (423,729 units) Initial Acquisition Date 7/7/20232024-01-012024-03-310001508655tslx:TwoThousandTwentyNineNotesMember2023-03-310001508655Debt Investments, Manufacturing, ASP Unifrax Holdings, Inc, First-lien loan (EUR 1,023 par, due 12/2025) Initial Acquisition Date 9/14/2023 Reference Rate and Spread E + 3.75% Interest Rate 7.65%2024-03-310001508655tslx:DelayedDrawAndRevolverMembertslx:HippoXpaBidcoAbMember2024-03-310001508655Equity and Other Investments Financial Services CLGF Holdco 2, LLC 334,682 Warrants Initial Acquisition Date 11/7/20232023-12-3100015086552022-12-310001508655tslx:DelayedDrawMembertslx:AlphaMidcoIncMember2024-03-310001508655Debt Investments Retail and Consumer Products Bed Bath and Beyond Inc. ABL FILO term loan ($12,823 par, due 8/2027) Initial Acquisition Date 9/2/2022 Reference Rate and Spread SOFR + 9.90% Interest Rate 15.23%2024-01-012024-03-310001508655Debt Investments Human Resource Support Services Employment Hero Holdings Pty Ltd. First-lien loan (AUD 50,000 par, due 12/2026) Initial Acquisition Date 12/6/2021 Reference Rate and Spread B + 6.25% Interest Rate 10.65%2024-03-310001508655Equity and Other Investments Financial Services AF Eagle Parent, L.P. Partnership (121,329 units) Initial Acquisition Date 11/27/20232023-12-310001508655tslx:AutomotiveMember2023-12-310001508655Equity and Other Investments Internet Services Piano Software, Inc. Series C-1 Preferred Shares (418,527 shares) Initial Acquisition Date 12/22/20212023-01-012023-12-310001508655Equity and Other Investments Structured Credit Gulf Stream Meridian, Series 2021-4A Structured Product ($1,015par,due7/2034) Initial Acquisition Date 6/3/2022 Reference Rate and Spread SOFR+6.61% Interest Rate 12.01%2023-01-012023-12-310001508655tslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel2Member2023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:ElysianFincoLtdMember2023-12-310001508655tslx:DelayedDrawMembertslx:BCTOAcePurchaserIncMember2023-12-310001508655Debt Investments Healthcare Homecare Software Solutions, LLC First-lien loan ($65,000 par, due 10/2026) Initial Acquisition Date 10/6/2021 Reference Rate and Spread SOFR + 5.70% Interest Rate 11.06%2023-12-310001508655Debt Investments Financial Services Volante Technologies, Inc. First-lien loan ($2,712 par, due 9/2028) Initial Acquisition Date 9/29/2023 Reference Rate and Spread 16.50% Interest Rate 16.50% PIK2024-03-310001508655Equity and Other Investments Business Services ReliaQuest, LLC Class A-2 Units (2,989 units) Initial Acquisition Date 6/21/20222024-01-012024-03-310001508655tslx:DelayedDrawAndRevolverMembertslx:NetwrixCorpMember2023-12-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. Series C Preferred Shares (1,915,114 shares) Initial Acquisition Date 10/13/20202023-12-310001508655tslx:InterestRateSwapTwoMember2024-01-012024-03-310001508655Debt Investments Manufacturing Avalara, Inc. First-lien loan ($38,636 par, due 10/2028) Initial Acquisition Date 10/19/2022 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.60%2023-12-310001508655Debt Investments Oil, Gas and Consumable Fuels Murchison Oil and Gas, LLC First-lien loan ($27,849 par, due 6/2026) Initial Acquisition Date 6/30/2022 Reference Rate and Spread SOFR + 8.65% Interest Rate 14.00%2023-01-012023-12-310001508655Debt Investments Healthcare SL Buyer Corp. First-lien loan ($31,475 par, due 7/2029) Initial Acquisition Date 7/7/2023 Reference Rate and Spread SOFR + 7.00% Interest Rate 12.36%2023-12-310001508655tslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputComparabilityAdjustmentMemberus-gaap:MarketApproachValuationTechniqueMembersrt:WeightedAverageMember2024-03-310001508655Interest Rate Swap Company Receives SOFR + 2.54% Maturity Date 11/1/20242023-12-310001508655Debt Investments, Manufacturing, Skylark UK DebtCo Limited, First-lien loan ($16,340 par, due 9/2030), Initial Acquisition Date 9/7/2023, Reference Rate and Spread, SOFR + 5.75%, Interest Rate 11.06%2024-03-310001508655tslx:DelayedDrawAndRevolverMembertslx:EmploymentHeroHoldingsPtyLtdMember2023-12-310001508655Debt Investments Healthcare2024-03-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. 106,592 Series D Warrants Initial Acquisition Date 4/8/20212024-01-012024-03-310001508655us-gaap:RevolvingCreditFacilityMembersrt:MaximumMember2024-01-012024-03-310001508655Equity and Other Investments Retail and Consumer Products American Achievement, Corp. Class A Units (687 units) Initial Acquisition Date 3/16/20212023-12-310001508655tslx:TwoThousandTwentySixNotesMemberus-gaap:SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember2024-01-012024-03-310001508655tslx:DelayedDrawMembertslx:OutsystemsLuxcoMember2023-12-310001508655Debt Investments Transportation Marcura Equities LTD First-lien loan ($32,007 par, due 8/2029) Initial Acquisition Date 8/11/2023 Reference Rate and Spread SOFR + 7.00% Interest Rate 12.18%2023-01-012023-12-310001508655tslx:RevolverMembertslx:DyeDurhamCorpMember2024-03-310001508655Equity and Other Investments Financial Services Newport Parent Holdings, L.P. Class A-2 Units (131,569 units) Initial Acquisition Date 12/10/20202023-12-310001508655Equity and Other Investments Structured Credit Dryden Senior Loan Fund, Series 2020-86A Structured Product ($1,500par,due7/2034) Initial Acquisition Date 8/17/2022 Reference Rate and Spread SOFR+6.76% Interest Rate 12.16%2023-01-012023-12-310001508655us-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:SecondLienDebtInvestmentsMembersrt:MinimumMemberus-gaap:MeasurementInputDiscountRateMember2023-12-310001508655Debt Investments Retail and Consumer Products American Achievement, Corp. First-lien loan ($1,352 par, due 9/2026) Initial Acquisition Date 6/10/2021 Reference Rate and Spread SOFR + 14.10% Interest Rate 18.94% PIK2023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:PassportLabsIncMember2023-12-310001508655Debt Investments Financial Services Bear OpCo, LLC First-lien loan ($21,392 par, due 10/2024) Initial Acquisition Date 10/10/2019 Reference Rate and Spread SOFR + 7.65% Interest Rate 13.01%2023-01-012023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:TangoManagementConsultingLLCMember2024-03-310001508655Equity and Other Investments Structured Credit Octagon 57 LLC, Series 2021-1A Structured Product ($1,000 par, due 10/2034) Initial Acquisition Date 5/24/2022 Reference Rate and Spread SOFR+ 6.86% Interest Rate 12.18%2024-03-310001508655Equity and Other Investments Structured Credit RR Ltd, Series 2020-8A Structured Product ($1,000par,due4/2033) Initial Acquisition Date 8/22/2022 Reference Rate and Spread SOFR+6.66% Interest Rate 12.06%2023-12-310001508655Equity and Other Investments Hotel, Gaming and Leisure IRGSE Holding Corp. Class C-1 Units (8,800,000 units) Initial Acquisition Date 12/21/20182024-03-310001508655tslx:DelayedDrawMembertslx:EDBParentLLCMember2024-03-310001508655Debt Investments Business Services Azurite Intermediate Holdings, Inc. First-lien loan ($13,062 par, due 3/2031) Initial Acquisition Date 3/19/2024 Reference Rate and Spread SOFR + 6.50% Interest Rate 11.83%2024-03-310001508655Equity and Other Investments Structured Credit Carlyle Global Market Strategies CLO Ltd, Series 2016-1, Ltd Structured Product ($1,600par,due4/2034) Initial Acquisition Date 2/15/2023 Reference Rate and Spread SOFR+6.86% Interest Rate 12.28%2023-12-310001508655tslx:TwoThousandTwentySixNotesMemberus-gaap:InterestRateSwapMember2024-01-012024-03-310001508655Debt Investments Business Services Alpha Midco, Inc. First-lien loan ($68,928 par, due 8/2025) Initial Acquisition Date 8/15/2019 Reference Rate and Spread SOFR + 7.63% Interest Rate 12.93%2024-03-310001508655us-gaap:TreasuryStockCommonMember2023-12-310001508655Interest Rate Swap Company Receives 3.875% Company SOFR + 2.51% Maturity Date 11/1/20242024-01-012024-03-310001508655tslx:RevolvingCreditFacilityMaturityOnJuneTwelveTwoThousandAndTwentyEightMember2024-03-310001508655Equity and Other Investments Structured Credit Park Avenue Institutional Advisers CLO Ltd, Series 2018-1A Structured Product ($1,000 par,due 10/2031) Initial Acquisition Date 9/23/2022 Reference Rate and Spread SOFR+ 3.59% Interest Rate 8.91%2024-03-310001508655Equity and Other Investments Healthcare Raptor US Buyer II Corp. 20,268 Ordinary Shares Initial Acquisition Date 3/24/20232023-01-012023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:TangoManagementConsultingLLCMember2023-12-310001508655Debt Investments Financial Services TradingScreen, Inc. First-lien loan ($50,078 par, due 4/2027) Initial Acquisition Date 4/30/2021 Reference Rate and Spread SOFR + 6.35% Interest Rate 11.66%2024-03-310001508655Debt Investments Education EMS Linq, Inc. First-lien revolving loan ($2,811 par, due 12/2027) Initial Acquisition Date 12/22/2021 Reference Rate and Spread SOFR + 6.35% Interest Rate 11.68%2024-03-310001508655tslx:TwoThousandTwentyEightNotesMember2024-01-012024-03-310001508655Debt Investments Human Resource Support Services PageUp People, Ltd. First-lien loan (AUD 11,938 par, due 12/2025) Initial Acquisition Date 1/11/2018 Reference Rate and Spread B + 5.00% Interest Rate 9.35%2024-01-012024-03-310001508655Equity and Other Investments Business Services ReliaQuest, LLC Class A-2 Units (2,989 units) Initial Acquisition Date 6/21/20222023-12-310001508655tslx:TwoThousandTwentyFourNotesMember2023-01-012023-12-310001508655Debt Investments Financial Services Kyriba Corp. First-lien loan (EUR 10,924 par, due 4/2028) Initial Acquisition Date 12/21/2023 Reference Rate and Spread E + 8.50% Interest Rate 12.42% (incl. 8.50% PIK)2023-12-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. 280,000 Series C Warrants Initial Acquisition Date 2/28/20202024-01-012024-03-310001508655Equity and Other Investments Structured Credit Crown Point CLO Ltd, Series 2021-10A Structured Product ($1,000par,due7/2034) Initial Acquisition Date 6/14/2022 Reference Rate and Spread SOFR+7.11% Interest Rate 12.53%2023-12-310001508655Debt Investments Retail and Consumer Products Bed Bath and Beyond Inc. Roll Up DIP term loan ($25,728 par, due 9/2024) Initial Acquisition Date 4/24/2023 Reference Rate and Spread SOFR + 7.90% Interest Rate 13.23% PIK2024-03-310001508655tslx:FirstLienDebtInvestmentsMembertslx:AssetValuationWaterfallMemberus-gaap:FairValueInputsLevel3Member2023-12-310001508655Equity and Other Investments Internet Services Piano Software, Inc. Series C-2 Preferred Shares (27,588 shares) Initial Acquisition Date 11/18/20222023-01-012023-12-310001508655Debt Investments Financial Services Passport Labs, Inc. First-lien loan ($24,857 par, due 4/2026) Initial Acquisition Date 4/28/2021 Reference Rate and Spread SOFR + 7.25% Interest Rate 15.75%2024-03-310001508655Debt Investments Oil, Gas and Consumable Fuels Murchison Oil and Gas, LLC First-lien loan ($24,637 par, due 6/2026) Initial Acquisition Date 6/30/2022 Reference Rate and Spread SOFR + 8.40% Interest Rate 13.72%2024-03-310001508655us-gaap:HealthcareSectorMember2023-12-310001508655Equity and Other Investments Structured Credit MidOcean Credit CLO Ltd, Series 2016-6A Structured Product ($3,500 par, due 4/2033) Initial Acquisition Date 5/23/2022 Reference Rate and Spread SOFR+ 3.78% Interest Rate 9.10%2024-03-310001508655tslx:DelayedDrawMembertslx:BenNevisMidcoLimitedMember2024-03-310001508655tslx:RevolverMembertslx:IRGSEHoldingCorpMember2023-12-310001508655Equity and Other Investments Education EMS Linq, Inc. Class B Units (5,522,526 units) Initial Acquisition Date 12/22/20212024-03-310001508655Equity and Other Investments Structured Credit Allegro CLO Ltd, Series 2018-1A, Structured Product ($1,000 par, due 6/2031) Initial Acquisition Date 5/26/2022 Reference Rate and Spread SOFR + 3.11% Interest Rate 8.51%2023-12-310001508655Equity and Other Investments Structured Credit Dryden Senior Loan Fund, Series 2020-86A Structured Product ($1,500par,due7/2034) Initial Acquisition Date 8/17/2022 Reference Rate and Spread SOFR+6.76% Interest Rate 12.08%2024-01-012024-03-310001508655Equity and Other Investments Structured Credit MidOcean Credit CLO Ltd, Series 2018-9A Structured Product ($1,100 par, due 7/2031) Initial Acquisition Date 6/1/2022 Reference Rate and Spread SOFR+ 6.31% Interest Rate 11.73%2023-01-012023-12-310001508655Debt Investments Human Resource Support Services PageUp People, Ltd. First-lien loan (GBP 3,104 par, due 12/2025) Initial Acquisition Date 10/28/2021 Reference Rate and Spread S + 5.03% Interest Rate 10.22%2023-01-012023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:CoupaHoldingsLLCMember2024-03-310001508655Debt Investments Education Astra Acquisition Corp. Second-lien loan ($43,479 par, due 10/2029) Initial Acquisition Date 10/22/2021 Reference Rate and Spread SOFR + 9.14% Interest Rate 14.48%2023-12-310001508655Equity and Other Investments Human Resource Support Services DaySmart Holdings, LLC Class A Units (166,811 units) Initial Acquisition Date 12/18/20202024-01-012024-03-310001508655tslx:RevolvingCreditFacilityMaturityOnApril232027Member2024-01-012024-03-310001508655tslx:DelayedDrawAndRevolverMembertslx:PdiTaHoldingsIncMember2024-03-310001508655Debt Investments Hotel Gaming and Leisure2024-03-310001508655Debt Investments Human Resource Support Services Axonify, Inc. First-lien loan ($41,607 par, due 5/2027) Initial Acquisition Date 5/5/2021 Reference Rate and Spread SOFR + 7.65% Interest Rate 13.04%2023-01-012023-12-310001508655Debt Investments, Manufacturing, Skylark UK DebtCo Limited, First-lien loan (GBP 16,640 par, due 9/2030), Initial Acquisition Date 9/7/2023, Reference Rate and Spread, S + 5.75%, Interest Rate 11.00%2024-01-012024-03-310001508655Debt Investments Financial Services Ibis US Blocker Co. First-lien loan ($16,514 par, due 5/2028) Initial Acquisition Date 5/28/2021 Reference Rate and Spread SOFR + 8.40% Interest Rate 13.74% (PIK)2024-01-012024-03-310001508655us-gaap:InterestRateSwapMembertslx:TwoThousandTwentyEightNotesMember2024-01-012024-03-310001508655us-gaap:CommonStockMember2024-03-310001508655Debt Investments Business Services OutSystems Luxco SARL First-lien loan (EUR 3,004 par, due 12/2028) Initial Acquisition Date 12/8/2022 Reference Rate and Spread E + 5.75% Interest Rate 9.58%2024-03-310001508655Debt Investments Business Services Information Clearinghouse, LLC and MS Market Service, LLC First-lien loan ($17,595 par, due 12/2026) Initial Acquisition Date 12/20/2021 Reference Rate and Spread SOFR + 6.65% Interest Rate 11.98%2024-01-012024-03-310001508655tslx:TransportationMember2023-12-310001508655Debt Investments Education Kangaroo Bidco AS First-lien loan ($30,625 par, due 11/2030) Initial Acquisition Date 11/2/2023 Reference Rate and Spread SOFR + 7.50% Interest Rate 12.90%2024-03-310001508655Debt Investments Education EMS Linq, Inc. First-lien revolving loan ($2,811 par, due 12/2027) Initial Acquisition Date 12/22/2021 Reference Rate and Spread SOFR + 6.35% Interest Rate 11.68%2024-01-012024-03-310001508655Debt Investments Communications Celtra Technologies, Inc. First-lien loan ($28,851 par, due 11/2026) Initial Acquisition Date 11/19/2021 Reference Rate and Spread SOFR + 5.75% Interest Rate 11.08%2024-03-310001508655Debt Investments Internet Services SMA Technologies Holdings, LLC First-lien loan ($36,833 par, due 10/2028) Initial Acquisition Date 10/31/2022 Reference Rate and Spread SOFR + 6.75% Interest Rate 12.11%2023-12-310001508655tslx:TruckLiteCoLlcMembertslx:DelayedDrawAndRevolverMember2024-03-310001508655Total Investments2024-03-310001508655Equity and Other Investments Internet Services Bayshore Intermediate #2, L.P. Co-Invest Common Units (8,837,008 units) Initial Acquisition Date 10/1/20212024-03-310001508655Equity and Other Investments Structured Credit Stewart Park CLO Ltd, Series 2015-1A Structured Product ($1,000 par,due 1/2030) Initial Acquisition Date 7/25/2022 Reference Rate and Spread SOFR+ 2.86% Interest Rate 8.26%2023-12-310001508655Debt Investments Retail and Consumer Products American Achievement, Corp. First-lien loan ($1,350 par, due 9/2026) Initial Acquisition Date 6/10/2021 Reference Rate and Spread SOFR + 14.10% Interest Rate 19.43% (incl. 19.18% PIK)2024-01-012024-03-310001508655tslx:OilGasAndConsumableFuelsMember2024-03-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. 106,592 Series D Warrants Initial Acquisition Date 4/8/20212023-12-310001508655Debt Investments Business Services Information Clearinghouse, LLC and MS Market Service, LLC First-lien loan ($17,640 par, due 12/2026) Initial Acquisition Date 12/20/2021 Reference Rate and Spread SOFR + 6.65% Interest Rate 12.02%2023-12-310001508655tslx:RevolvingCreditFacilityMaturityOnFebruary42026Member2024-03-310001508655Debt Investments Internet Services SMA Technologies Holdings, LLC First-lien loan ($36,833 par, due 10/2028) Initial Acquisition Date 10/31/2022 Reference Rate and Spread SOFR + 6.75% Interest Rate 12.06%2024-03-310001508655tslx:EquityAndOtherInvestmentsMember2023-01-012023-12-310001508655us-gaap:RevolvingCreditFacilityMembersrt:MaximumMember2023-12-310001508655Debt Investments Chemicals Erling Lux Bidco SARL First-lien loan (NOK 7,427 par, due 9/2028) Initial Acquisition Date 9/6/2022 Reference Rate and Spread N + 6.75% Interest Rate 11.45%2024-01-012024-03-310001508655tslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMemberus-gaap:MeasurementInputComparabilityAdjustmentMemberus-gaap:MarketApproachValuationTechniqueMember2023-12-310001508655Debt Investments Retail and Consumer Products Neuintel, LLC First-lien loan ($57,701 par, due 12/2026) Initial Acquisition Date 12/20/2021 Reference Rate and Spread SOFR + 7.65% Interest Rate 13.03%2023-01-012023-12-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. Series C Preferred Shares (1,816,295 shares) Initial Acquisition Date 4/8/20212024-01-012024-03-310001508655tslx:TwentyTwentyFourNotesMember2019-11-012019-11-300001508655us-gaap:InterestRateSwapMember2023-12-310001508655us-gaap:IncomeApproachValuationTechniqueMembertslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMemberus-gaap:MeasurementInputDiscountRateMember2024-03-310001508655us-gaap:CommonStockMember2022-12-310001508655tslx:TwoThousandTwentyNineNotesMember2024-01-082024-01-080001508655Equity and Other Investments Financial Services AF Eagle Parent, L.P. Partnership (121,329 units) Initial Acquisition Date 11/27/20232024-01-012024-03-310001508655Debt Investments Manufacturing Skylark UK DebtCo Limited First-lien loan ($16,340 par, due 9/2030) Initial Acquisition Date 9/7/2023 Reference Rate and Spread SOFR + 6.25% Interest Rate 11.60%2023-01-012023-12-310001508655Debt Investments Internet Services2023-12-310001508655Equity and Other Investments Structured Credit Wind River CLO Ltd, Series 2014-2A Structured Product ($1,500par,due 1/2031) Initial Acquisition Date 6/23/2022 Reference Rate and Spread SOFR+ 3.16% Interest Rate 8.48%2024-03-310001508655Debt Investments Business Services Wrangler TopCo, LLC First-lien loan ($4,153 par, due 7/2029) Initial Acquisition Date 7/7/2023 Reference Rate and Spread SOFR + 7.50% Interest Rate 12.88%2023-12-310001508655Equity and Other Investments Financial Services Passport Labs, Inc. 17,534 Warrants Initial Acquisition Date 4/28/20212023-01-012023-12-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. 280,000 Series C Warrants Initial Acquisition Date 2/28/20202023-12-310001508655tslx:BlackScholesModelMembertslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Member2024-03-310001508655Debt Investments Oil, Gas and Consumable Fuels Laramie Energy, LLC First-lien loan ($27,317 par, due 2/2027) Initial Acquisition Date 2/21/2023 Reference Rate and Spread SOFR + 7.10% Interest Rate 12.46%2023-01-012023-12-310001508655tslx:RetailAndConsumerProductsMember2024-03-310001508655Equity and Other Investments Oil, Gas and Consumable Fuels Murchison Oil and Gas, LLC 13,355 Preferred Units Initial Acquisition Date 6/30/20222023-01-012023-12-310001508655Equity and Other Investments Hotel, Gaming and Leisure IRGSE Holding Corp. Class A Units (33,790,171 units) Initial Acquisition Date 12/21/20182024-01-012024-03-310001508655tslx:HotelGamingAndLeisureMember2024-03-310001508655Equity and Other Investments Structured Credit Battalion CLO Ltd, Series 2021-21A Structured Product ($1,300par,due7/2034) Initial Acquisition Date 7/13/2022 Reference Rate and Spread SOFR+3.56% Interest Rate 8.96%2023-12-310001508655Equity and Other Investments Structured Credit Cedar Funding CLO Ltd, Series 2018-7A Structured Product ($1,000par,due1/2031) Initial Acquisition Date 7/21/2022 Reference Rate and Spread SOFR+4.81% Interest Rate 10.23%2023-12-310001508655us-gaap:OverAllotmentOptionMember2023-06-122023-06-120001508655country:DE2024-03-310001508655Equity and Other Investments Business Services Insight Hideaway Aggregator, L.P. Partnership Interest (329,861 units) Initial Acquisition Date 3/19/20242024-03-310001508655Debt Investments Financial Services CLGF Holdco 2, LLC First-lien loan ($3,916 par, due 11/2027) Initial Acquisition Date 11/7/2023 Reference Rate and Spread SOFR + 8.50% Interest Rate 13.85%2023-01-012023-12-310001508655tslx:AdviserMemberus-gaap:GeneralAndAdministrativeExpenseMembertslx:AdministrationAgreementMember2024-01-012024-03-310001508655us-gaap:ValuationTechniqueDiscountedCashFlowMembertslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Member2024-03-310001508655Debt Investments Retail and Consumer Products American Achievement, Corp. First-lien loan ($1,350 par, due 9/2026) Initial Acquisition Date 6/10/2021 Reference Rate and Spread SOFR + 14.10% Interest Rate 19.43% (incl. 19.18% PIK)2024-03-310001508655Debt Investments Internet Services Bayshore Intermediate #2, L.P. First-lien revolving loan ($480 par, due 10/2027) Initial Acquisition Date 10/1/2021 Reference Rate and Spread SOFR + 6.60% Interest Rate 12.01%2023-12-310001508655Debt Investments Insurance Disco Parent, Inc. First-lien loan ($4,545 par, due 3/2029) Initial Acquisition Date 3/30/2023 Reference Rate and Spread SOFR + 7.50% Interest Rate 12.84%2024-01-012024-03-310001508655Equity and Other Investments Structured Credit Voya CLO Ltd, Series 2018-3A Structured Product ($2,750 par, due 10/2031) Initial Acquisition Date 6/22/2022 Reference Rate and Spread SOFR+ 6.01% Interest Rate 11.41%2023-12-310001508655tslx:TwoThousandTwentySixNotesMember2023-12-310001508655Debt Investments Business Services BCTO Ignition Purchaser, Inc. First-lien holdco loan ($32,913 par, due 10/2030) Initial Acquisition Date 4/18/2023 Reference Rate and Spread SOFR + 9.00% Interest Rate 14.30% PIK2024-03-310001508655Debt Investments Business Services ReliaQuest Holdings, LLC First-lien loan ($82,626 par, due 10/2026) Initial Acquisition Date 10/8/2020 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.56%2024-01-012024-03-310001508655Debt Investments Business Services BCTO Ignition Purchaser, Inc. First-lien holdco loan ($31,935 par, due 10/2030) Initial Acquisition Date 4/18/2023 Reference Rate and Spread SOFR + 9.00% Interest Rate 14.40% PIK2023-01-012023-12-310001508655tslx:DelayedDrawMembertslx:BanyanSoftwareHoldingsLlcMember2024-03-310001508655Debt Investments Retail and Consumer Products 99 Cents Only Stores LLC ABL FILO term loan ($25,000 par, due 5/2025) Initial Acquisition Date 9/6/2017 Reference Rate and Spread SOFR + 8.65% Interest Rate 14.03%2023-12-310001508655Debt Investments Human Resource Support Services Axonify, Inc. First-lien loan ($41,607 par, due 5/2027) Initial Acquisition Date 5/5/2021 Reference Rate and Spread SOFR + 7.65% Interest Rate 13.04%2023-12-310001508655Equity and Other Investments Healthcare Raptor US Buyer II Corp. 20,268 Ordinary Shares Initial Acquisition Date 3/24/20232023-12-310001508655Debt Investments Financial Services PrimeRevenue, Inc. First-lien loan ($7,007 par, due 12/2024) Initial Acquisition Date 12/31/2018 Reference Rate and Spread SOFR + 7.10% Interest Rate 12.43%2024-01-012024-03-310001508655Equity and Other Investments Structured Credit Carlyle Global Market Strategies CLO Ltd, Series 2018-1A Structured Product ($1,550par,due4/2031) Initial Acquisition Date 8/11/2020 Reference Rate and Spread SOFR+6.01% Interest Rate 11.42%2023-12-310001508655Debt Investments Business Services Galileo Parent, Inc. First-lien loan ($64,579 par, due 5/2030) Initial Acquisition Date 5/3/2023 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.56%2024-01-012024-03-310001508655tslx:ControlledAffiliatedInvestmentsMember2023-01-012023-03-310001508655Debt Investments Human Resource Support Services bswift, LLC First-lien loan ($44,246 par, due 11/2028) Initial Acquisition Date 11/7/2022 Reference Rate and Spread SOFR + 6.38% Interest Rate 11.70%2024-03-310001508655country:AU2023-12-310001508655Debt Investments Financial Services BlueSnap, Inc. First-lien loan ($41,895 par, due 10/2025) Initial Acquisition Date 10/25/2019 Reference Rate and Spread SOFR + 7.15% Interest Rate 12.50%2023-12-310001508655Debt Investments Healthcare SL Buyer Corp. First-lien loan ($31,875 par, due 7/2029) Initial Acquisition Date 7/7/2023 Reference Rate and Spread SOFR + 7.75% Interest Rate 13.08%2024-01-012024-03-310001508655us-gaap:LetterOfCreditMember2024-03-310001508655Debt Investments Business Services BCTO Ignition Purchaser, Inc. First-lien holdco loan ($32,913 par, due 10/2030) Initial Acquisition Date 4/18/2023 Reference Rate and Spread SOFR + 9.00% Interest Rate 14.30% PIK2024-01-012024-03-310001508655Equity and Other Investments Financial Services Oxford Square Capital Corp. Common Shares (1,620 shares) Initial Acquisition Date 8/5/20152023-01-012023-12-310001508655us-gaap:NondesignatedMember2024-03-310001508655Equity and Other Investments Structured Credit Voya CLO Ltd, Series 2018-3A Structured Product ($2,750 par, due 10/2031) Initial Acquisition Date 6/22/2022 Reference Rate and Spread SOFR+ 6.01% Interest Rate 11.33%2024-01-012024-03-3100015086552023-01-012023-03-310001508655Debt Investments Business Services Galileo Parent, Inc. First-lien revolving loan ($3,317 par, due 5/2029) Initial Acquisition Date 5/3/2023 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.60%2023-01-012023-12-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. Series D Preferred Shares (1,240,740 shares) Initial Acquisition Date 5/11/20212024-01-012024-03-310001508655Debt Investments Retail and Consumer Products 99 Cents Only Stores LLC ABL FILO term loan ($25,000 par, due 5/2025) Initial Acquisition Date 9/6/2017 Reference Rate and Spread SOFR + 8.65% Interest Rate 13.97%2024-03-310001508655country:LU2024-03-310001508655Debt Investments Oil, Gas and Consumable fuels, Mach Natural Resources LP First-lien loan ($5,000 par, due 12/2026) Initial Acquisition Date12/28/2023 Reference Rate and Spread SOFR + 6.65% Interest Rate 11.95%2024-03-310001508655Debt Investments Retail and Consumer Products Tango Management Consulting, LLC First-lien loan ($57,007 par, due 12/2027) Initial Acquisition Date 12/1/2021 Reference Rate and Spread SOFR + 6.85% Interest Rate 12.20%2023-01-012023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:CoupaHoldingsLLCMember2023-12-310001508655Debt Investments Business Services Artisan Bidco, Inc First-lien loan (EUR 17,735 par, due 11/2029) Initial Acquisition Date 11/7/2023 Reference Rate and Spread E + 7.00% Interest Rate 10.96%2023-12-310001508655Debt Investments Business Services Netwrix Corp First-lien loan ($46,358 par, due 6/2029) Initial Acquisition Date 6/9/2022 Reference Rate and Spread SOFR + 5.00% Interest Rate 10.30%2024-01-012024-03-310001508655us-gaap:CommonStockMember2023-12-310001508655tslx:AutomotiveMember2024-03-310001508655Hedge Accounting Swaps2024-01-012024-03-310001508655tslx:TwentyTwentyEightNotesMember2024-01-012024-03-310001508655Debt Investments Transportation Marcura Equities LTD First-lien revolving loan ($1,667 par, due 8/2029) Initial Acquisition Date 8/11/2023 Reference Rate and Spread SOFR + 7.00% Interest Rate 12.18%2023-01-012023-12-310001508655Debt Investments Transportation Marcura Equities LTD First-lien loan ($32,007 par, due 8/2029) Initial Acquisition Date 8/11/2023 Reference Rate and Spread SOFR + 7.00% Interest Rate 12.18%2023-12-3100015086552023-05-150001508655Debt Investments Communications IntelePeer Holdings, Inc. Convertible note ($4,790 par, due 5/2028) Initial Acquisition Date 5/12/2021 Reference Rate and Spread 7.50% Interest Rate 7.50% PIK2024-03-310001508655Equity and Other Investments Business Services ReliaQuest, LLC Class A-1 Units (637,713 units) Initial Acquisition Date 11/23/20212023-12-310001508655Equity and Other Investments Internet Services Piano Software, Inc. Series C-1 Preferred Shares (418,527 shares) Initial Acquisition Date 12/22/20212023-12-310001508655Debt Investments Hotel, Gaming and Leisure Equinox Holdings, Inc First-lien loan ($48,044 par, due 3/2029) Initial Acquisition Date 3/8/2024 Reference Rate and Spread SOFR + 8.25% Interest Rate 13.56%(incl. 4.13% PIK)2024-03-310001508655Equity and Other Investments Hotel, Gaming and Leisure IRGSE Holding Corp. Class A Units (33,790,171 units) Initial Acquisition Date 12/21/20182023-12-310001508655us-gaap:FairValueInputsLevel3Membertslx:SecondLienDebtInvestmentsMember2024-01-012024-03-310001508655Equity and Other Investments Structured Credit Wind River CLO Ltd, Series 2017-1A Structured Product ($3,000par, due 4/2036) Initial Acquisition Date 7/14/2022 Reference Rate and Spread SOFR+ 3.98% Interest Rate 9.38%2023-12-310001508655tslx:DelayedDrawMembertslx:SlBuyerCorpMember2024-03-310001508655tslx:FirstLienDebtInvestmentsMember2023-03-310001508655tslx:ManufacturingMember2024-03-310001508655Debt Investments Human Resource Support Services bswift, LLC First-lien loan ($44,358 par, due 11/2028) Initial Acquisition Date 11/7/2022 Reference Rate and Spread SOFR + 6.63% Interest Rate 12.03%2023-12-310001508655Equity and Other Investments Structured Credit MidOcean Credit CLO Ltd, Series 2018-9A Structured Product ($1,100 par, due 7/2031) Initial Acquisition Date 6/1/2022 Reference Rate and Spread SOFR+ 6.31% Interest Rate 11.63%2024-03-310001508655tslx:TwoThousandTwentyFourNotesMember2020-01-012020-12-310001508655tslx:FirstLienDebtInvestmentsMember2022-12-310001508655Debt Investments Internet Services Coupa Holdings, LLC First-lien loan ($43,191 par, due 2/2030) Initial Acquisition Date 2/27/2023 Reference Rate and Spread SOFR + 7.50% Interest Rate 12.86%2023-12-310001508655Debt Investments Human Resource Support Services PrimePay Intermediate, LLC First-lien loan ($34,375 par, due 12/2026) Initial Acquisition Date 12/17/2021 Reference Rate and Spread SOFR + 7.15% Interest Rate 12.54%2023-12-310001508655Equity and Other Investments Business Services ReliaQuest, LLC Class A-2 Units (2,989 units) Initial Acquisition Date 6/21/20222024-03-310001508655Debt Investments Communications2023-12-310001508655Equity and Other Investments Structured Credit Ares CLO Ltd, Series 2021-59A Structured Product ($1,000par,due4/2034) Initial Acquisition Date 6/23/2022 Reference Rate and Spread SOFR+6.51% Interest Rate 11.89%2023-12-310001508655Equity and Other Investments Structured Credit Wind River CLO Ltd, Series 2018-3A Structured Product ($2,000par,due 1/2031) Initial Acquisition Date 12/12/2022 Reference Rate and Spread SOFR+ 5.91% Interest Rate 11.33%2023-01-012023-12-310001508655Equity and Other Investments Structured Credit Octagon Investment Partners 38 Ltd, Series 2018-1A Structured Product ($2,800 par, due 7/2030) Initial Acquisition Date 9/20/2022 Reference Rate and Spread SOFR+ 3.21% Interest Rate 8.63%2023-01-012023-12-310001508655Equity and Other Investments Structured Credit Magnetite CLO Ltd, Series 2021-30A Structured Product ($1,000 par, due 10/2034) Initial Acquisition Date 6/13/2022 Reference Rate and Spread SOFR+ 6.46% Interest Rate 11.84%2023-12-310001508655Debt Investments Retail and Consumer Products American Achievement, Corp. Subordinated note ($4,740 par, due 9/2026) Initial Acquisition Date 3/16/2021 Reference Rate and Spread SOFR + 1.15% Interest Rate 6.48% PIK2024-01-012024-03-310001508655Debt Investments Financial Services Ping Identity Holding Corp. First-lien loan ($22,727 par, due 10/2029) Initial Acquisition Date 10/17/2022 Reference Rate and Spread SOFR + 7.00% Interest Rate 12.36%2023-01-012023-12-310001508655Equity and Other Investments Healthcare Merative Topco L.P. 989,691 Class A-1 Units Initial Acquisition Date 6/30/20222024-03-310001508655tslx:DelayedDrawMembertslx:AlphaMidcoIncMember2023-12-310001508655Debt Investments Business Services ForeScout Technologies, Inc. First-lien loan ($5,476 par, due 8/2026) Initial Acquisition Date 7/1/2022 Reference Rate and Spread SOFR + 8.10% Interest Rate 13.45%2023-01-012023-12-310001508655tslx:RevolverMembertslx:AvalaraIncMember2024-03-310001508655Equity and Other Investments Structured Credit Carlyle Global Market Strategies CLO Ltd, Series 2014-4RA Structured Product ($1,000par,due7/2030) Initial Acquisition Date 5/26/2022 Reference Rate and Spread SOFR+3.16% Interest Rate 8.48%2024-03-310001508655Equity and Other Investments Financial Services2023-12-310001508655tslx:RevolvingCreditFacilityMaturityOnApril242029Member2024-04-240001508655Debt Investments Automotive Truck-Lite Co., LLC First-lien loan ($40,437 par, due 2/2031) Initial Acquisition Date 2/13/2024 Reference Rate and Spread SOFR + 5.75% Interest Rate 11.06%2024-03-310001508655Debt Investments Hotel, Gaming and Leisure IRGSE Holding Corp. First-lien loan ($30,261 par, due 6/2024) Initial Acquisition Date 12/21/2018 Reference Rate and Spread SOFR + 9.65% Interest Rate 14.96%2024-03-310001508655Debt Investments Education2024-03-310001508655us-gaap:DomesticCountryMember2024-03-310001508655tslx:TwoThousandTwentyEightNotesMember2023-01-012023-12-310001508655Debt Investments Oil, Gas and Consumable fuels, Mach Natural Resources LP First-lien loan ($5,000 par, due 12/2026) Initial Acquisition Date12/28/2023 Reference Rate and Spread SOFR + 6.65% Interest Rate 11.95%2024-01-012024-03-310001508655Debt Investments Communications IntelePeer Holdings, Inc. Convertible note ($4,700 par, due 5/2028) Initial Acquisition Date 5/12/2021 Reference Rate and Spread 7.50% Interest Rate 7.50% PIK2023-01-012023-12-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. Series D Preferred Shares (1,598,874 shares) Initial Acquisition Date 4/8/20212024-03-310001508655tslx:InterestRateSwapThreeMember2023-01-012023-03-310001508655Equity and Other Investments Structured Credit Dryden Senior Loan Fund, Series 2018-55A Structured Product ($1,000par,due4/2031)Initial Acquisition Date 7/25/2022 Reference Rate and Spread SOFR+3.11% Interest Rate 8.51%2023-12-310001508655Debt Investments Retail and Consumer Products American Achievement, Corp. Subordinated note ($4,740 par, due 9/2026) Initial Acquisition Date 3/16/2021 Reference Rate and Spread SOFR + 1.15% Interest Rate 6.54% PIK2023-01-012023-12-310001508655Debt Investments Internet Services Lithium Technologies, LLC First-lien loan ($58,342 par, due 1/2025) Initial Acquisition Date 10/3/2017 Reference Rate and Spread SOFR + 9.00% Interest Rate 14.32% (incl. 4.50% PIK)2024-01-012024-03-310001508655Debt Investments Retail and Consumer Products American Achievement, Corp. First-lien loan ($27,046 par, due 9/2026) Initial Acquisition Date 9/30/2015 Reference Rate and Spread SOFR + 6.35% Interest Rate 11.19% PIK2023-01-012023-12-310001508655Equity and Other Investments Business Services ReliaQuest, LLC Class A-3 Units (16,957 units) Initial Acquisition Date 11/10/20232023-01-012023-12-310001508655tslx:DelayedDrawMembertslx:AxonifyIncMember2024-03-310001508655Equity and Other Investments Structured Credit KKR CLO Ltd, 49A Structured Product ($1,000 par, due 7/2035) Initial Acquisition Date 6/2/2022 Reference Rate and Spread SOFR+ 8.26% Interest Rate 13.42%2023-01-012023-12-3100015086552024-03-052024-03-050001508655tslx:TwoThousandTwentySixNotesMemberus-gaap:SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember2023-01-012023-12-310001508655Equity and Other Investments Business Services ReliaQuest, LLC Class A-3 Units (16,957 units) Initial Acquisition Date 11/10/20232023-12-310001508655Equity and Other Investments Business Services ReliaQuest, LLC Class A-1 Units (637,713 units) Initial Acquisition Date 11/23/20212024-03-310001508655us-gaap:IncomeApproachValuationTechniqueMembertslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputDiscountRateMembersrt:WeightedAverageMember2023-12-310001508655Debt Investments Chemicals Erling Lux Bidco SARL First-lien revolving loan (GBP 312 par, due 9/2028) Initial Acquisition Date 9/6/2022 Reference Rate and Spread S + 6.75% Interest Rate 11.98%2023-12-310001508655tslx:MezzanineDebtInvestmentsMember2023-03-310001508655Debt Investments Financial Services CLGF Holdco 2, LLC Second-lien loan ($3,357 par, due 11/2028) Initial Acquisition Date 11/7/2023 Reference Rate and Spread SOFR + 12.00% Interest Rate 17.35%2023-01-012023-12-310001508655tslx:SecondLienDebtInvestmentsMember2023-01-012023-03-310001508655us-gaap:RevolvingCreditFacilityMember2024-01-012024-03-310001508655Debt Investments Financial Services BTRS Holdings, Inc. First-lien revolving loan ($1,205 par, due 12/2028) Initial Acquisition Date 12/16/2022 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.63%2023-01-012023-12-310001508655Equity and Other Investments Structured Credit American Money Management Corp CLO Ltd, Series 2016-18A Structured Product ($1,500 par,due 5/2031) Initial Acquisition Date 6/22/2022 Reference Rate and Spread SOFR+3.31% Interest Rate 8.70%2023-12-310001508655Equity and Other Investments Retail and Consumer Products2024-03-310001508655Equity and Other Investments Structured Credit Stewart Park CLO Ltd, Series 2015-1A Structured Product ($1,000 par,due 1/2030) Initial Acquisition Date 7/25/2022 Reference Rate and Spread SOFR+ 2.86% Interest Rate 8.26%2023-01-012023-12-310001508655Debt Investments Business Services Acceo Solutions, Inc. First-lien loan (CAD 52,941 par, due 10/2025) Initial Acquisition Date 7/6/2018 Reference Rate and Spread C + 4.75% Interest Rate 10.21%2023-12-310001508655Debt Investments Manufacturing2023-12-310001508655Debt Investments Internet Services Lithium Technologies, LLC First-lien loan ($57,665 par, due 1/2025) Initial Acquisition Date 10/3/2017 Reference Rate and Spread SOFR + 9.00% Interest Rate 14.39% (incl. 4.50% PIK)2023-12-310001508655us-gaap:RevolvingCreditFacilityMemberus-gaap:BaseRateMembersrt:MaximumMember2024-03-310001508655Debt Investments Business Services Wrangler TopCo, LLC First-lien loan ($4,153 par, due 7/2029) Initial Acquisition Date 7/7/2023 Reference Rate and Spread SOFR + 7.50% Interest Rate 12.88%2023-01-012023-12-310001508655tslx:EducationMember2023-12-310001508655Equity and Other Investments Education Astra 2L Holdings II LLC Membership Interest (10.17% ownership) Initial Acquisition Date 1/13/20222023-01-012023-12-310001508655Debt Investments Business Services Artisan Bidco, Inc First-lien loan ($38,112 par, due 11/2029) Initial Acquisition Date 11/7/2023 Reference Rate and Spread SOFR + 7.00% Interest Rate 12.38%2023-01-012023-12-310001508655tslx:EquityAndOtherInvestmentsMember2024-03-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. 633,376 Warrants Initial Acquisition Date 9/21/20182023-01-012023-12-310001508655Equity and Other Investments Human Resource Support Services bswift, LLC Class A-1 Units (2,393,509 units) Initial Acquisition Date 11/7/20222023-12-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. 569,991 Warrants Initial Acquisition Date 4/2/20202023-01-012023-12-310001508655Debt Investments Manufacturing Heritage Environmental Services, Inc. First-lien loan ($12,346 par, due 1/2031) Initial Acquisition Date 1/31/2024 Reference Rate and Spread SOFR + 5.50% Interest Rate 10.81%2024-03-310001508655Equity and Other Investments Business Services Newark FP Co-Invest, L.P. Partnership (2,527,719 units) Initial Acquisition Date 11/8/20232023-01-012023-12-310001508655Debt Investments Transportation Marcura Equities LTD First-lien revolving loan ($1,667 par, due 8/2029) Initial Acquisition Date 8/11/2023 Reference Rate and Spread SOFR + 7.00% Interest Rate 12.18%2023-12-310001508655Debt Investments Healthcare Edge Bidco B.V First-lien loan (EUR 3,850 par, due 2/2029) Initial Acquisition Date 2/24/2023 Reference Rate and Spread E + 7.00% Interest Rate 16.10% (incl. 3.25% PIK)2023-01-012023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:MarcuraEquitiesLtdMember2023-12-310001508655Equity and Other Investments Structured Credit CIFC CLO Ltd, Series 2018-3A Structured Product ($1,000par,due7/2031)Initial Acquisition Date 6/16/2022 Reference Rate and Spread SOFR+5.76% Interest Rate 11.16%2023-01-012023-12-310001508655Debt Investments Retail and Consumer Products Rapid Data GmbH Unternehmensberatung, First-lien loan (EUR 4,495 par, due 7/2029), Initial Acquisition Date 7/11/2023 Reference Rate and Spread E + 6.50% Interest Rate 10.43%2024-03-310001508655Debt Investments Business Services2023-12-310001508655Debt Investments Manufacturing ASP Unifrax Holdings, Inc. Secured Note ($91 par, due 9/2028) Initial Acquisition Date 12/19/2023 Reference Rate and Spread 5.25% Interest Rate 5.25%2023-01-012023-12-310001508655tslx:RevolvingCreditFacilityMaturityOnApril242029Member2024-04-242024-04-240001508655tslx:MezzanineDebtInvestmentsMember2023-12-310001508655Debt Investments Retail and Consumer Products Bed Bath and Beyond Inc. ABL FILO term loan ($12,823 par, due 8/2027) Initial Acquisition Date 9/2/2022 Reference Rate and Spread SOFR + 9.90% Interest Rate 15.23%2024-03-310001508655Debt Investments Business Services Artisan Bidco, Inc First-lien loan ($38,015 par, due 11/2029) Initial Acquisition Date 11/7/2023 Reference Rate and Spread SOFR + 7.00% Interest Rate 12.32%2024-01-012024-03-310001508655tslx:InterestRateSwapFourMember2024-01-012024-03-310001508655tslx:TwentyTwentyFourNotesMember2020-02-052020-02-050001508655Debt Investments Financial Services PrimeRevenue, Inc. First-lien loan ($9,007 par, due 12/2024) Initial Acquisition Date 12/31/2018 Reference Rate and Spread SOFR + 7.10% Interest Rate 12.46%2023-12-310001508655country:DE2023-12-310001508655Interest Rate Swap Company Pays SOFR + 2.17% Maturity Date 8/1/20262024-03-310001508655tslx:EMSLinqIncMembertslx:RevolverMember2024-03-310001508655Equity and Other Investments Structured Credit Dryden Senior Loan Fund, Series 2020-86A Structured Product ($1,500par,due7/2034) Initial Acquisition Date 8/17/2022 Reference Rate and Spread SOFR+6.76% Interest Rate 12.16%2023-12-310001508655us-gaap:RetainedEarningsMember2022-12-310001508655Equity and Other Investments Human Resource Support Services2024-03-310001508655Debt Investments Retail and Consumer Products American Achievement, Corp. Subordinated note ($4,740 par, due 9/2026) Initial Acquisition Date 3/16/2021 Reference Rate and Spread SOFR + 1.15% Interest Rate 6.48% PIK2024-03-310001508655srt:MaximumMembertslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputComparabilityAdjustmentMemberus-gaap:MarketApproachValuationTechniqueMember2023-12-310001508655tslx:RevolvingCreditFacilityMaturityOnFebruary42026Member2024-01-012024-03-310001508655Debt Investments Education Astra Acquisition Corp. Second-lien loan ($43,479 par, due 10/2029) Initial Acquisition Date 10/22/2021 Reference Rate and Spread SOFR + 9.14% Interest Rate 14.44%2024-01-012024-03-310001508655Debt Investments Oil, Gas and Consumable Fuels Laramie Energy, LLC First-lien loan ($27,317 par, due 2/2027) Initial Acquisition Date 2/21/2023 Reference Rate and Spread SOFR + 7.10% Interest Rate 12.43%2024-03-310001508655Debt Investments Internet Services EDB Parent, LLC First-lien loan ($63,508 par, due 7/2028) Initial Acquisition Date 7/7/2022 Reference Rate and Spread SOFR + 6.75% Interest Rate 12.10%2023-12-310001508655Equity and Other Investments Financial Services Newport Parent Holdings, L.P. Class A-2 Units (131,569 units) Initial Acquisition Date 12/10/20202024-01-012024-03-310001508655Debt Investments Manufacturing Skylark UK DebtCo Limited First-lien loan ($16,340 par, due 9/2030) Initial Acquisition Date 9/7/2023 Reference Rate and Spread SOFR + 6.25% Interest Rate 11.60%2023-12-310001508655tslx:TwoThousandTwentyThreeNotesMember2018-01-310001508655tslx:TwoThousandTwentyFourNotesMemberus-gaap:InterestRateSwapMember2024-01-012024-03-310001508655tslx:SecondLienDebtInvestmentsMember2024-01-012024-03-310001508655Debt Investments Internet Services LeanTaaS Holdings, Inc. First-lien loan ($36,966 par, due 7/2028) Initial Acquisition Date 7/12/2022 Reference Rate and Spread SOFR + 7.50% Interest Rate 12.85%2023-12-310001508655tslx:OtherMember2023-12-310001508655Debt Investments Human Resource Support Services Madcap Software, Inc First-lien loan ($32,419 par, due 12/2026) Initial Acquisition Date 12/15/2023 Reference Rate and Spread SOFR + 6.10% Interest Rate 11.43%2024-03-310001508655us-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMembersrt:WeightedAverageMember2023-12-310001508655tslx:TwentyTwentyFourNotesMember2024-01-012024-03-310001508655Equity and Other Investments Human Resource Support Services Employment Hero Holdings Pty Ltd. Series E Preferred Shares (113,250 shares) Initial Acquisition Date 3/1/20222024-01-012024-03-310001508655tslx:DelayedDrawMembertslx:BabylonFincoLimitedMember2024-03-310001508655Equity and Other Investments Structured Credit Crown Point CLO Ltd, Series 2021-10A Structured Product ($1,000par,due7/2034) Initial Acquisition Date 6/14/2022 Reference Rate and Spread SOFR+7.11% Interest Rate 12.43%2024-03-310001508655Debt Investments Education EMS Linq, Inc. First-lien loan ($56,216 par, due 12/2027) Initial Acquisition Date 12/22/2021 Reference Rate and Spread SOFR + 6.35% Interest Rate 11.68%2024-01-012024-03-310001508655Equity and Other Investments Retail and Consumer Products Neuintel, LLC Class A Units (1,176,494 units) Initial Acquisition Date 12/21/20212023-12-31iso4217:AUDiso4217:EURxbrli:pureiso4217:SEKxbrli:sharesiso4217:CADiso4217:GBPiso4217:USDxbrli:sharesiso4217:USDiso4217:NOK