10-K 1 tslx-20231231.htm 10-K 10-K
FYfalse0001508655http://fasb.org/us-gaap/2023#InterestExpense http://fasb.org/us-gaap/2023#UnrealizedGainLossOnDerivativeshttp://fasb.org/us-gaap/2023#InterestExpense http://fasb.org/us-gaap/2023#UnrealizedGainLossOnDerivativeshttp://fasb.org/srt/2023#CumulativeEffectPeriodOfAdoptionAdjustmentMemberhttp://sixthstreetspecialtylending.com/20231231#NetChangeInUnrealizedGainsLossesOnInvestmentsAndForeignCurrencyTranslationhttp://sixthstreetspecialtylending.com/20231231#NetRealizedGainsLossesOnInvestmentsAndForeignCurrencyTranslationhttp://sixthstreetspecialtylending.com/20231231#NetChangeInUnrealizedGainsLossesOnInvestmentsAndForeignCurrencyTranslationhttp://sixthstreetspecialtylending.com/20231231#NetRealizedGainsLossesOnInvestmentsAndForeignCurrencyTranslation0001508655Equity 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 L + 6.25% Interest Rate 8.96%2022-01-012022-12-3100015086552019-12-310001508655tslx:LeantaasHoldingsIncMembertslx:DelayedDrawMember2022-12-310001508655Debt Investments Retail and Consumer Products Neuintel, LLC First-lien loan ($56,400 par, due 12/2026) Initial Acquisition Date 12/20/2021 Reference Rate and Spread L + 6.25% Interest Rate 10.76%2022-12-310001508655tslx:TwentyTwentySixNotesMember2022-12-310001508655Interest Rate Swap Company Receives L + 2.11% Company Pays 4.50% Maturity Date 8/1/2022 Two2022-01-012022-12-310001508655Debt 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%2023-12-310001508655Equity and Other Investments Structured Credit Eaton CLO Ltd, Series 2015-1A Structured Product ($2,500 par, due 1/2030) Initial Acquisition Date 6/23/2022 Reference Rate and Spread L + 2.50% Interest Rate 5.21%2022-12-310001508655Debt Investments Human Resource Support Services PrimePay Intermediate, LLC First-lien loan ($32,242 par, due 12/2026) Initial Acquisition Date 12/17/2021 Reference Rate and Spread SOFR + 7.15% Interest Rate 11.73%2022-12-3100015086552015-08-040001508655tslx:HumanResourceSupportServicesMember2023-12-310001508655Equity and Other Investments Financial Services Oxford Square Capital Corp. Common Shares (1,620 shares) Initial Acquisition Date 8/5/20152022-12-310001508655Non-controlled, Affiliated Investments2022-01-012022-12-310001508655Debt 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%2023-12-310001508655Total Investments2023-12-310001508655srt:CumulativeEffectPeriodOfAdoptionAdjustmentMember2020-12-310001508655tslx:TwentyTwentyFourNotesMember2019-12-310001508655Equity and Other Investments Hotel, Gaming and Leisure IRGSE Holding Corp. Class A Units (33,790,171 units) Initial Acquisition Date 12/21/20182022-01-012022-12-310001508655tslx:TwentyTwentyThreeNotesMember2023-01-012023-12-310001508655tslx:TwoThousandTwentyFourNotesMember2022-01-012022-12-310001508655Debt Investments Retail and Consumer Products2023-12-310001508655Equity 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 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%2023-01-012023-12-310001508655Equity 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%2023-01-012023-12-310001508655Debt Investments Retail and Consumer Products Bed Bath and Beyond Inc. ABL FILO term loan ($55,000 par, due 8/2027) Initial Acquisition Date 9/2/2022 Reference Rate and SOFR + 7.90% Interest Rate 12.30%2022-01-012022-12-3100015086552016-12-310001508655tslx:RevolvingCreditsFacilitiesMember2018-12-310001508655Equity and Other Investments Human Resource Support Services Bswift LLC Class A-1 Units (2,393,509 units) Initial Acquisition Date 11/7/20222022-01-012022-12-310001508655us-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:SecondLienDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMember2022-12-310001508655tslx:BaseDividendMember2023-08-032023-08-030001508655Interest Rate Swap Company Receives L + 2.11% Maturity Date 8/1/20222022-12-310001508655Equity and Other Investments Marketing Services Validity, Inc. Series A Preferred Shares (3,840,000 shares) Initial Acquisition Date 5/31/20182023-12-310001508655tslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:NonControlledAffiliatedInvestmentsMember2023-01-012023-12-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. 633,376 Warrants Initial Acquisition Date 9/21/20182023-12-310001508655Equity and Other Investments Oil, Gas and Consumable Fuels2022-12-310001508655tslx:InvestmentAdvisoryAgreementMember2011-04-152011-04-150001508655Debt 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%2023-01-012023-12-310001508655us-gaap:RevolvingCreditFacilityMembersrt:MaximumMember2023-06-120001508655us-gaap:AdditionalPaidInCapitalMembersrt:CumulativeEffectPeriodOfAdoptionAdjustmentMember2020-12-310001508655Debt Investments Hotel, Internet Services Lucidworks, Inc. First-lien loan ($8,330 par, due 2/2027) Initial Acquisition Date 2/11/2022 Reference Rate Spread SOFR + 7.50% Interest Rate 11.82% (incl. 3.50% PIK)2022-12-310001508655tslx:DelayedDrawMembertslx:IbisIntermediateCoMember2022-12-310001508655Debt Investments, Manufacturing,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%2023-01-012023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:EmploymentHeroHoldingsPtyLtdMember2023-12-3100015086552021-09-300001508655tslx:TwoThousandTwentyFourNotesMember2020-02-050001508655tslx:TwoThousandTwentyTwoConvertibleNotesMember2022-08-012022-08-010001508655Equity 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%2023-01-012023-12-310001508655tslx:TwoThousandTwentyEightNotesMember2023-12-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. 106,592 Series D Warrants Initial Acquisition Date 4/8/20212023-12-310001508655Interest Rate Swap Company Receives L + 2.11% Company Pays 4.50% Maturity Date 8/1/20222022-01-012022-12-310001508655tslx:DelayedDrawMembertslx:BearOpCoLLCMember2022-12-310001508655tslx:ControlledAffiliatedInvestmentsMember2023-01-012023-12-310001508655Interest Rate Swap Company Pays L + 1.59% Maturity Date 8/1/20222022-12-310001508655Equity and Other Investments Oil, Gas and Consumable Fuels TRP Assets, LLC Partnership Interest (1.89% ownership) Initial Acquisition Date 8/25/20222023-12-310001508655Debt Investments Oil, Gas and Consumable Fuels2022-12-310001508655Debt Investments Financial Services Kyriba Corp. First-lien revolving loan ($1,411 par, due 4/2025) Initial Acquisition Date 4/9/2019 Reference Rate and Spread L + 7.25% Interest Rate 11.98%2022-12-310001508655Debt Investments Business services Dye & Durham Corp. First-lien revolving loan (CAD 1,448 par, due 12/2026) Initial Acquisition Date 12/3/2021 Reference Rate and Spread P + 6.75% Interest Rate 11.2%2022-12-310001508655tslx:BaseDividendMember2021-05-042021-05-040001508655Equity and Other Investments Business Services Warrior TopCo LP Class A Units (423,728 units) Initial Acquisition Date 7/7/20232023-01-012023-12-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. Series C Preferred Shares (1,816,295 shares) Initial Acquisition Date 4/8/20212022-01-012022-12-310001508655Debt 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 + 6.25%, Interest Rate 11.60%2023-01-012023-12-310001508655Debt Investments Financial Services Bear OpCo, LLC First-lien loan ($20,169 par, due 10/2024) Initial Acquisition Date 10/10/2019 Reference Rate and Spread SOFR + 7.65% Interest Rate 11.97%2022-01-012022-12-310001508655tslx:TwoThousandTwentyTwoConvertibleNotesMember2021-10-012021-12-310001508655tslx:ConvertibleSeniorNotesDueTwentyTwentyTwoMember2018-12-3100015086552022-04-012022-06-300001508655Interest Rate Swap Company Receives SOFR + 2.54% Maturity Date 11/1/20242023-12-310001508655tslx:RevolvingCreditFacilityMaturityOnFebruary42026Member2023-01-012023-12-310001508655tslx:SpecialDividendMember2021-02-172021-02-170001508655us-gaap:RevolvingCreditFacilityMember2023-04-250001508655Debt Investments Retail and Consumer Products Tango Management Consulting, LLC First-lien loan ($44,674 par, due 12/2027) Initial Acquisition Date 12/1/2021 Reference Rate and Spread L + 6.75% Interest Rate 10.49%2022-12-310001508655Debt 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%2023-01-012023-12-310001508655Equity 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 L + 6.58% Interest Rate 9.35%2022-12-3100015086552022-12-310001508655Equity and Other Investments Education EMS Linq, Inc. Class B Units (5,522,526 units) Initial Acquisition Date 12/22/20212023-12-310001508655tslx:SpecialDividendMember2021-11-020001508655tslx:EducationMember2022-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:HornetsecurityHoldingGmbhMember2023-12-310001508655Debt 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%2023-01-012023-12-310001508655us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InterestRateSwapMemberus-gaap:InterestExpenseMember2023-01-012023-12-310001508655Debt Investments Other Omnigo Software, LLC First-lien loan ($40,353 par, due 3/2026) Initial Acquisition Date 12/3/2021 Reference Rate Spread SOFR + 6.60% Interest Rate 10.92%2022-12-310001508655Equity and Other Investments Retail and Consumer Products2022-12-310001508655Debt Investments Business Services Netwrix Corp First-lien loan ($36,594 par, due 6/2029) Initial Acquisition Date 6/9/2022 Reference Rate and Spread SOFR + 5.00% Interest Rate 10.39%2023-01-012023-12-310001508655tslx:DelayedDrawMembertslx:BCTOAcePurchaserIncMember2022-12-310001508655tslx:SupplementalDividendMember2022-02-172022-02-170001508655tslx:MezzanineDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Member2023-12-310001508655Debt Investments Business Services Wrangler TopCo, LLC First-lien loan ($4,043,546 par, due 7/2029) Initial Acquisition Date 7/7/2023 Reference Rate and Spread SOFR + 7.50% Interest Rate 12.88%2023-12-310001508655tslx:BlackScholesModelMembertslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Member2023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:PageUpPeopleLtdMember2022-12-310001508655Debt Investments Human Resource Support Services Axonify, Inc First-lien loan ($44,806 par, due 11/2028) Initial Acquisition Date 11/7/2022 Reference Rate and Spread SOFR + 6.63% Interest Rate 10.81%2022-12-310001508655Equity 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%2023-12-3100015086552016-01-012016-12-310001508655tslx:BaseDividendMember2023-02-160001508655Equity and Other Investments Business Services Artisan Topco LP Class A Preferred Units (2,117,264 units) Initial Acquisition Date 11/7/20232023-01-012023-12-310001508655Debt 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%2023-12-310001508655us-gaap:IncomeApproachValuationTechniqueMembertslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputDiscountRateMembersrt:WeightedAverageMember2022-12-310001508655tslx:TwentyTwentyTwoConvertibleNotesMember2018-06-012018-06-300001508655tslx:TwoThousandTwentyThreeNotesMember2022-12-310001508655Debt Investments Transportation Project44, Inc. First-lien loan ($35,139 par, due 11/2027) Initial Acquisition Date 11/12/2021 Reference Rate and Spread L + 6.25% Interest Rate 11.41%2022-01-012022-12-310001508655Equity and Other Investments Structured Credit Ares CLO Ltd, Series 2021-59A StructuredProduct ($1,000par,due4/2034) Initial Acquisition Date 6/23/2022 Reference Rate and Spread SOFR+6.51% Interest Rate 11.89%2023-01-012023-12-310001508655Debt Investments Human Resource Support Services Elysian Finco Ltd First-lien loan ($17,314 par, due 1/2028) Initial Acquisition Date 1/31/2022 Reference Rate and Spread SOFR + 6.65% Interest Rate 10.99%2022-01-012022-12-310001508655Equity and Other Investments Retail and Consumer Products Copper Bidco, LLC Trust Certificates (132,928 Certificates) Initial Acquisition Date 12/7/20202022-12-310001508655tslx:InsuranceMember2023-12-310001508655Debt 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)2023-01-012023-12-310001508655Equity 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%2023-12-310001508655Equity and Other Investments Retail and Consumer Products American Achievement, Corp. Class A Units (687 units) Initial Acquisition Date 3/16/20212022-12-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. Series C Preferred Shares (1,816,295 shares) Initial Acquisition Date 4/8/20212022-12-310001508655Debt 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%2023-01-012023-12-310001508655Equity and Other Investments Retail and Consumer Products2023-12-310001508655tslx:DelayedDrawMembertslx:NeuintelLLCMember2022-12-310001508655Debt 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 10.39%2023-12-310001508655Debt 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 11.26%2023-12-310001508655Equity and Other Investments Structured Credit Dryden Senior Loan Fund, Series 2020-86A Structured Product ($1,500 par, due 7/2034) Initial Acquisition Date 8/17/2022 Reference Rate and Spread L + 6.50% Interest Rate 9.24%2022-12-310001508655Debt 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 + 6.25%, Interest Rate 11.60%2023-12-310001508655Debt Investments Retail and Consumer Products Bed Bath and Beyond Inc. ABL FILO term loan ($55,000 par, due 8/2027) Initial Acquisition Date 9/2/2022 Reference Rate and SOFR + 7.90% Interest Rate 12.30%2022-12-310001508655tslx:RevolverAndPartnershipInterestMembertslx:CrewlineBuyerIncMember2023-12-310001508655Debt Investments Hotel, Gaming and Leisure IRGSE Holding Corp First-lien loan ($30,261 par, due 6/2023) Initial Acquisition Date 9/29/2015 Reference Rate and Spread L + 9.50% Interest Rate 14.19%2022-01-012022-12-310001508655Equity and Other Investments Financial Services Oxford Square Capital Corp. Common Shares (1,620 shares) Initial Acquisition Date 8/5/20152023-01-012023-12-310001508655Controlled Affiliated Investments2023-01-012023-12-310001508655Equity and Other Investments Human Resource Support Services2023-12-310001508655Debt Investments Hotel, Office Products USR Parent, Inc. ABL FILO term loan ($19,000 par, due 4/2027) Initial Acquisition Date 4/25/2022 Reference Rate Spread SOFR + 6.50% Interest Rate 10.62%2022-12-310001508655Equity and Other Investments2022-12-310001508655Equity and Other Investments Business Services Sprinklr, Inc. Common Shares (315,005 shares) Initial Acquisition Date 6/24/20212023-01-012023-12-310001508655Non-controlled Affiliated Investments MD America Energy, LLC2022-01-012022-12-310001508655Debt Investments Communications Celtra Technologies, Inc. First-lien loan ($34,650 par, due 11/2026) Initial Acquisition Date 11/19/2021 Reference Rate and Spread L + 7.00% Interest Rate 11.38%2022-01-012022-12-310001508655Equity and Other Investments Financial Services CLGF Holdco 2, LLC 334,682 Warrants Initial Acquisition Date 11/7/20232023-01-012023-12-310001508655Interest Rate Swap Company Receives 4.50% Company Pays L + 1.60% Maturity Date 8/1/20222022-01-012022-12-310001508655Debt Investments Hotel, Internet Services EDB Parent, LLC First-lien loan ($56,963 par, due 7/2028) Initial Acquisition Date 7/7/2022 Reference Rate Spread SOFR + 7.00% Interest Rate 11.58%2022-12-310001508655Debt Investments Hotel, Internet Services SMA Technologies Holdings, LLC First-lien loan ($36,833 par, due 10/2028) Initial Acquisition Date 10/31/2022 Reference Rate Spread SOFR + 6.75% Interest Rate 11.07%2022-01-012022-12-310001508655tslx:AmericanAchievementCorpMembertslx:RevolverMember2023-12-310001508655us-gaap:CommonStockMember2023-01-012023-12-310001508655tslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMemberus-gaap:MeasurementInputComparabilityAdjustmentMemberus-gaap:MarketApproachValuationTechniqueMember2022-12-310001508655Equity and Other Investments Financial Services Newport Parent Holdings, L.P. Class A-2 Units (131,569 units) Initial Acquisition Date 12/10/20202023-01-012023-12-310001508655tslx:BaseDividendMember2022-02-172022-02-170001508655Debt 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 8.73%2022-12-310001508655us-gaap:DomesticCountryMember2022-01-012022-12-310001508655Equity and Other Investments Structured Credit Carlyle Global Market Strategies CLO Ltd, Series 2014-4RA Structured Product ($1,000 par, due 7/2030) Initial Acquisition Date 3/26/2022 Reference Rate and Spread L + 2.90% Interest Rate 5.41%2022-01-012022-12-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. 106,592 Series D Warrants Initial Acquisition Date 4/8/20212023-01-012023-12-310001508655tslx:TwentyTwentyEightNotesMember2023-12-310001508655Equity 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%2023-01-012023-12-310001508655us-gaap:RetainedEarningsMember2022-01-012022-12-310001508655Equity 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%2023-01-012023-12-310001508655us-gaap:IncomeApproachValuationTechniqueMembertslx:MezzanineDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputDiscountRateMember2022-12-310001508655tslx:NonControlledNonAffiliatedInvestmentsMember2022-01-012022-12-310001508655tslx:DelayedDrawMembertslx:EDBParentLLCMember2023-12-310001508655Debt 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%2023-12-310001508655tslx:TwoThousandTwentyFourNotesMemberus-gaap:SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember2023-09-252023-09-250001508655Equity and Other Investments Structured Credit Carlyle Global Market Strategies CLO Ltd, Series 2018-1A Structured Product ($1,550 par, due 4/2031) Initial Acquisition Date 8/11/2020 Reference Rate and Spread L + 5.75% Interest Rate 8.46%2022-12-310001508655tslx:InterestRateSwapSevenMember2022-01-012022-12-310001508655Interest Rate Swap Company Pays 3.875% Maturity Date 11/1/20242023-12-310001508655Equity and Other Investments Financial Services AvidXchange, Inc. Common Shares (200,721 shares) Initial Acquisition Date 10/15/20212022-01-012022-12-310001508655tslx:InterestRateSwapTwoMember2022-01-012022-12-310001508655Equity and Other Investments Financial Services TradingScreen, Inc. Class A Units (600,000 units) Initial Acquisition Date 5/14/20212022-01-012022-12-310001508655Debt 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 12.03% (incl. 6.50% PIK)2023-12-310001508655Equity and Other Investments Structured Credit Signal Peak CLO LLC, Series 2018-5A Structured Product ($1,000 par, due 4/2031) Initial Acquisition Date 8/9/2022 Reference Rate and Spread L + 5.65% Interest Rate 8.43%2022-01-012022-12-310001508655Interest Rate Swap Company Receives 3.875% Company Pays L + 2.46% Maturity Date 11/1/20242022-01-012022-12-310001508655tslx:EquityAndOtherInvestmentsMember2021-12-310001508655tslx:TwoThousandTwentyNineNotesMemberus-gaap:SubsequentEventMember2024-01-082024-01-080001508655Debt 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 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 Structured Credit KKR CLO Ltd, 49A Structured Product ($1,000 par, due 7/2035) Initial Acquisition Date 6/2/2022 Reference Rate and Spread L + 8.00% Interest Rate 10.17%2022-01-012022-12-310001508655Equity 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%2023-01-012023-12-310001508655Equity and Other Investments Communications Celtra Technologies, Inc. Class A Units (1,250,000 units) Initial Acquisition Date 11/19/20212023-01-012023-12-310001508655Debt 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 14.03%2023-01-012023-12-310001508655Debt 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%2023-01-012023-12-310001508655Equity and Other Investments Structured Credit Cedar Funding CLO Ltd, Series 2018-7A Structured Product ($1,000 par, due 1/2031) Initial Acquisition Date 7/21/2022 Reference Rate and Spread L + 4.55% Interest Rate 7.26%2022-12-310001508655tslx:TwentyTwentyThreeNotesMember2019-12-310001508655Equity and Other Investments Human Resource Support Services ClearCompany, LLC Series A Preferred Units (1,429,228 units) Initial Acquisition Date 8/24/20182022-01-012022-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:MarcuraEquitiesLtdMember2023-12-310001508655tslx:EquityAndOtherInvestmentsMember2022-12-310001508655srt:MaximumMembertslx:PharmaceuticalsMember2023-12-310001508655tslx:AssetValuationWaterfallMemberus-gaap:FairValueInputsLevel3Membertslx:SecondLienDebtInvestmentsMember2023-12-310001508655Equity and Other Investments Financial Services Passport Labs, Inc. 17,534 Warrants Initial Acquisition Date 4/28/20212023-01-012023-12-310001508655us-gaap:RevolvingCreditFacilityMemberus-gaap:BaseRateMembersrt:MaximumMember2023-12-310001508655tslx:NonControlledAffiliatedInvestmentsMember2021-01-012021-12-310001508655Debt 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%2023-01-012023-12-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. Series D Preferred Shares (1,598,874 shares) Initial Acquisition Date 4/8/20212023-01-012023-12-310001508655tslx:TwoThousandTwentyNineNotesMemberus-gaap:SubsequentEventMember2024-01-080001508655Equity 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%2023-01-012023-12-310001508655Debt 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%2023-12-310001508655tslx:TwoThousandTwentyFourNotesMembertslx:ThreeMonthLiborMember2022-01-012022-12-310001508655Debt Investments Communications Celtra Technologies, Inc. First-lien loan ($34,650 par, due 11/2026) Initial Acquisition Date 11/19/2021 Reference Rate and Spread L + 7.00% Interest Rate 11.38%2022-12-310001508655us-gaap:RetainedEarningsMember2023-12-310001508655tslx:DelayedDrawMembertslx:IbisIntermediateCoMember2023-12-310001508655Equity and Other Investments Business Services ReliaQuest, LLC Class A-2 Units (2,580 units) Initial Acquisition Date 6/21/20222022-01-012022-12-310001508655Debt 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%2023-12-310001508655tslx:RevolvingCreditFacilityMaturityOnApril232027Member2023-12-310001508655tslx:TwoThousandTwentyTwoConvertibleNotesMember2023-01-012023-12-310001508655tslx:BaseDividendMember2021-11-020001508655Debt 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%2023-12-310001508655Debt Investments Human Resource Support Services Axonify, Inc First-lien loan ($47,122 par, due 5/2026) Initial Acquisition Date 5/5/2021 Reference Rate and Spread SOFR + 7.65% Interest Rate 11.83%2022-12-310001508655Equity and Other Investments Structured Credit Shackelton CLO Ltd, Series 2015-7RA Structured Product ($1,000 par, due 7/2031) Initial Acquisition Date 5/23/2022 Reference Rate and Spread L + 3.33% Interest Rate 5.84%2022-01-012022-12-310001508655Interest Rate Swap Company Receives L+2.28% Company Pays 3.875% Maturity Date 11/1/20242022-12-310001508655Debt Investments Retail and Consumer Products Cordance Operations, LLC First-lien loan ($32,907 par, due 7/2028) Initial Acquisition Date 7/25/2022 Reference Rate and SOFR + 8.75% Interest Rate 13.27%2022-12-310001508655tslx:SupplementalDividendMember2023-11-022023-11-020001508655tslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputComparabilityAdjustmentMemberus-gaap:MarketApproachValuationTechniqueMember2022-12-310001508655tslx:BusinessServicesMember2023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:BtrsHoldingIncMember2023-12-310001508655Debt Investments Hotel, Internet Services Lithium Technologies, LLC First-lien loan ($54,700 par, due 1/2024) Initial Acquisition Date 10/3/2017 Reference Rate Spread SOFR + 8.00% Interest Rate 12.06%2022-12-310001508655Debt 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%2023-01-012023-12-310001508655Interest Rate Swap Company Receives 4.50% Company Pays L + 1.59% Maturity Date 8/1/20222022-01-012022-12-310001508655Derivative Interest Rate Swap2022-01-012022-12-310001508655Debt Investments Hotel, Gaming and Leisure IRGSE Holding Corp First-lien revolving loan ($16,747 par, due 6/2023) Initial Acquisition Date 9/29/2015 Reference Rate and Spread L + 9.50% Interest Rate 14.23%2022-12-310001508655Debt 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%2023-12-310001508655srt:MaximumMembercountry:FI2023-12-310001508655Equity and Other Investments Financial Services AF Eagle Parent, L.P. Partnership (121,329 units) Initial Acquisition Date 11/27/20232023-12-310001508655tslx:DelayedDrawMembertslx:PrimePayIntermediateLLCMember2022-12-310001508655Debt Investments Hotel, Office Products USR Parent, Inc. ABL FILO term loan ($19,000 par, due 4/2027) Initial Acquisition Date 4/25/2022 Reference Rate Spread SOFR + 6.50% Interest Rate 10.62%2022-01-012022-12-310001508655us-gaap:NondesignatedMember2022-12-310001508655tslx:HumanResourceSupportServicesMember2022-12-310001508655Debt 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%2023-12-310001508655Debt Investments Chemicals2022-12-310001508655tslx:DelayedDrawMembertslx:ExtraHopNetworksIncMember2023-12-310001508655Equity 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%2023-01-012023-12-3100015086552021-02-230001508655country:NO2023-12-310001508655Equity and Other Investments Human Resource Support Services DaySmart Holdings, LLC Class A Units (166,811 units) Initial Acquisition Date 12/8/20202023-12-310001508655tslx:RisksRelatedToEconomicConditionsMember2023-01-012023-12-310001508655Equity and Other Investments Structured Credit Dryden Senior Loan Fund, Series 2020-86A Structured Product ($1,500 par, due 7/2034) Initial Acquisition Date 8/17/2022 Reference Rate and Spread L + 6.50% Interest Rate 9.24%2022-01-012022-12-310001508655tslx:WestMember2022-12-310001508655Equity and Other Investments Business Services Mitnick TA Aggregator, L.P. Membership Interest (0.43% ownership) Initial Acquisition Date 5/2/20222023-01-012023-12-310001508655us-gaap:ValuationTechniqueDiscountedCashFlowMembertslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Member2022-12-310001508655Equity 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 11.02%2023-01-012023-12-310001508655Debt 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 L + 1.00% Interest Rate 4.75% PIK2022-01-012022-12-310001508655Debt Investments Human Resource Support Services Modern Hire, Inc First-lien loan ($28,878 par, due 5/2024) Initial Acquisition Date 5/15/2019 Reference Rate and Spread L + 7.00% Interest Rate 11.38%2022-12-310001508655us-gaap:InterestRateSwapMember2023-12-310001508655Equity and Other Investments Healthcare Merative Topco L.P. 989,691 Class A-1 Units Initial Acquisition Date 6/30/20222023-01-012023-12-310001508655Equity 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 Education Astra 2L Holdings II LLC Membership Interest (10.17% ownership) Initial Acquisition Date 1/13/20222022-12-310001508655tslx:DelayedDrawMembertslx:LucidworksIncMember2023-12-310001508655Debt Investments Human Resource Support Services PayScale Holdings, Inc. First-lien loan ($68,775 par, due 5/2024) Initial Acquisition Date 5/3/2019 Reference Rate and Spread L + 5.75% Interest Rate 10.48%2022-01-012022-12-310001508655Debt 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 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%2023-12-310001508655tslx:RevolvingCreditsFacilitiesMember2015-12-310001508655us-gaap:FairValueInputsLevel3Membertslx:SecondLienDebtInvestmentsMember2022-01-012022-12-310001508655Non-controlled Affiliated Investments SMPA Holdings, LLC2022-12-310001508655country:DE2022-12-310001508655Equity 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%2023-12-310001508655Equity 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 L + 3.05% Interest Rate 6.06%2022-12-310001508655Interest Rate Swap Company Receives 2.50% Company Pays L + 1.91% Maturity Date 8/1/20262022-01-012022-12-310001508655us-gaap:AdditionalPaidInCapitalMember2020-12-310001508655Equity and Other Investments Education Astra 2L Holdings II LLC Membership Interest (10.17% ownership) Initial Acquisition Date 1/13/20222023-01-012023-12-310001508655Interest Rate Swap Company Receives 2.50% Company Pays SOFR + 2.17% Maturity Date 8/1/20262023-01-012023-12-310001508655Debt 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)2023-01-012023-12-310001508655tslx:TwoThousandTwentyTwoConvertibleNotesMember2023-12-310001508655Equity 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%2023-12-310001508655tslx:InterestRateSwapOneMember2023-01-012023-12-310001508655Debt 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:AsgIiLlcMember2022-12-310001508655Debt Investments Business Services2022-12-310001508655Equity and Other Investments Internet Services2022-12-310001508655Equity 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%2023-01-012023-12-310001508655tslx:SupplementalDividendMember2022-05-032022-05-030001508655tslx:TwoThousandTwentySixNotesMember2021-02-032021-02-030001508655tslx:DelayedDrawAndRevolverMembertslx:TangoManagementConsultingLLCMember2023-12-310001508655tslx:InterestRateSwapFourMember2022-01-012022-12-310001508655Equity 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 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%2023-12-310001508655tslx:TwentyTwentyEightNotesMember2023-08-142023-08-140001508655Debt 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)2023-12-310001508655Debt 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%2023-12-310001508655tslx:TwoThousandTwentyFourNotesMember2019-11-300001508655Equity and Other Investments Structured Credit Shackelton CLO Ltd, Series 2015-7RA Structured Product ($1,000 par, due 7/2031) Initial Acquisition Date 5/23/2022 Reference Rate and Spread L + 3.33% Interest Rate 5.84%2022-12-310001508655tslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMemberus-gaap:MeasurementInputComparabilityAdjustmentMemberus-gaap:MarketApproachValuationTechniqueMember2023-12-310001508655Equity and Other Investments Human Resource Support Services DaySmart Holdings, LLC Class A Units (166,811 units) Initial Acquisition Date 10/1/20192022-01-012022-12-310001508655Debt 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%2023-12-310001508655Equity 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 Structured Credit2022-12-310001508655Equity 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 L + 3.33% Interest Rate 6.04%2022-01-012022-12-310001508655Debt Investments Business services ForeScout Technologies, Inc. First-lien loan ($2,606 par, due 8/2026) Initial Acquisition Date 7/1/2022Reference Rate and Spread L + 9.00%Interest Rate13.72% (incl. 9.00% PIK)2022-01-012022-12-310001508655tslx:FirstLienDebtInvestmentsMember2023-01-012023-12-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. 633,376 Warrants Initial Acquisition Date 9/21/20182022-01-012022-12-310001508655tslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Member2023-01-012023-12-310001508655Equity and Other Investments Financial Services Oxford Square Capital Corp. Common Shares (1,620 shares) Initial Acquisition Date 8/5/20152022-01-012022-12-310001508655us-gaap:FairValueInputsLevel2Member2023-12-310001508655tslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Member2023-12-310001508655tslx:SupplementalDividendMember2021-08-032021-08-030001508655tslx:BaseDividendMember2021-08-032021-08-030001508655country:LU2022-12-310001508655Debt Investments, Transportation, Marcura Equities LTD, Inc, First-lien revolving loan ($32,007 par, due 8/2029), Initial Acquisition Date 8/11/2023, Reference Rate and Spread, SOFR + 7.00%, Interest Rate 12.18%2023-12-310001508655tslx:RevolvingCreditsFacilitiesMember2023-12-310001508655tslx:SouthMember2022-12-310001508655Equity 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 Human Resource Support Services bswift, LLC Class A-1 Units (2,393,509 units) Initial Acquisition Date 11/7/20222023-12-310001508655Debt Investments Financial Services Bear OpCo, LLC First-lien loan ($20,169 par, due 10/2024) Initial Acquisition Date 10/10/2019 Reference Rate and Spread SOFR + 7.65% Interest Rate 11.97%2022-12-310001508655Debt 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%2023-12-310001508655Equity and Other Investments Structured Credit CIFC CLO Ltd, Series 2018-3A Structured Product ($1,000 par, due 7/2031) Initial Acquisition Date 6/16/2022 Reference Rate and Spread L + 5.50% Interest Rate 8.24%2022-12-310001508655Debt Investments Financial Services Passport Labs, Inc. First-lien loan ($23,390 par, due 4/2026) Initial Acquisition Date 4/28/2021 Reference Rate and Spread L + 8.25% Interest Rate 12.58% (incl. 4.125% PIK)2022-01-012022-12-310001508655Debt 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 L + 1.00% Interest Rate 4.75% PIK2022-12-310001508655tslx:CommunicationsMember2023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:CoupaHoldingsLLCMember2023-12-310001508655tslx:OilGasAndConsumableFuelsMember2023-12-310001508655tslx:InterestRateSwapFiveMember2023-01-012023-12-310001508655Debt Investments Financial Services Ibis Intermediate Co. First-lien loan ($1,526 par, due 5/2027) Initial Acquisition Date 5/28/2021 Reference Rate and Spread L + 5.00% Interest Rate 9.73%2022-12-310001508655Debt Investments Retail and Consumer Products Cordance Operations, LLC First-lien loan ($32,907 par, due 7/2028) Initial Acquisition Date 7/25/2022 Reference Rate and SOFR + 8.75% Interest Rate 13.27%2022-01-012022-12-310001508655us-gaap:IncomeApproachValuationTechniqueMembertslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMemberus-gaap:MeasurementInputDiscountRateMember2023-12-310001508655tslx:PrimeRevenueIncMembertslx:RevolverMember2022-12-310001508655Equity and Other Investments Structured Credit RR Ltd, Series 2020-8A Structured Product ($1,000 par, due 4/2033) Initial Acquisition Date 8/22/2022 Reference Rate and Spread L + 6.40% Interest Rate 8.91%2022-01-012022-12-310001508655Debt Investments Financial Services Kyriba Corp. First-lien revolving loan (EUR 336 par, due 4/2025) Initial Acquisition Date 4/9/2019 Reference Rate and Spread E + 7.25% Interest Rate 9.45%2022-12-310001508655us-gaap:ValuationTechniqueDiscountedCashFlowMembertslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Member2023-12-310001508655tslx:BusinessServicesMember2022-12-310001508655tslx:TwoThousandTwentyFourNotesMember2023-01-012023-12-310001508655Equity and Other Investments Human Resource Support Services Employment Hero Holdings Pty Ltd. Series E Preferred Shares (113,250 shares) Initial Acquisition Date 3/1/20222022-12-310001508655Debt 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%2023-12-310001508655us-gaap:FinancialServicesSectorMember2023-12-310001508655us-gaap:InterestRateSwapMembertslx:TwoThousandTwentyEightNotesMember2023-01-012023-12-310001508655us-gaap:AdditionalPaidInCapitalMember2023-01-012023-12-310001508655Equity 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%2023-01-012023-12-310001508655Debt 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%2023-12-310001508655Interest Rate Swap Company Receives 4.50% Maturity Date 1/22/20232022-12-310001508655Debt 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 Hotel, Internet Services Workwell Bayshore Intermediate #2, L. First-lien revolving loan ($780 par, due 10/2027) Initial Acquisition Date 10/1/2021 Reference Rate Spread L + 7.75% Interest Rate 10.89%2022-12-310001508655Debt 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 17.35%2023-12-310001508655Equity and Other Investments Pharmaceuticals TherapeuticsMD, Inc. 14,256 Warrants Initial Acquisition Date 8/5/20202023-01-012023-12-310001508655tslx:ConvertibleSeniorNotesDueTwentyNineteenMember2016-12-310001508655Controlled Affiliated Investments2023-12-310001508655Debt 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%2023-01-012023-12-310001508655Debt Investments Business services ForeScout Technologies, Inc. First-lien loan ($2,606 par, due 8/2026) Initial Acquisition Date 7/1/2022Reference Rate and Spread L + 9.00%Interest Rate13.72% (incl. 9.00% PIK)2022-12-310001508655Debt Investments Human Resource Support Services PrimePay Intermediate, LLC First-lien loan ($32,242 par, due 12/2026) Initial Acquisition Date 12/17/2021 Reference Rate and Spread SOFR + 7.15% Interest Rate 11.73%2022-01-012022-12-310001508655Equity and Other Investments Education EMS Linq, Inc. Class B Units (5,522,526 units) Initial Acquisition Date 12/22/20212023-01-012023-12-310001508655tslx:SecondLienDebtInvestmentsMember2023-12-310001508655Hedge Accounting Swaps2022-12-310001508655Equity and Other Investments Financial Services TradingScreen, Inc. Class A Units (600,000 units) Initial Acquisition Date 5/14/20212022-12-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. Series D Preferred Shares (1,598,874 shares) Initial Acquisition Date 4/8/20212022-01-012022-12-310001508655Debt Investments Healthcare Integrated Practice Solutions, Inc. First-lien loan ($46,312 par, due 10/2024) Initial Acquisition Date 6/30/2017 Reference Rate and Spread L + 7.50% Interest Rate 11.89%2022-01-012022-12-3100015086552022-08-012022-08-010001508655Debt Investments Financial Services Kyriba Corp. First-lien revolving loan (EUR 336 par, due 4/2025) Initial Acquisition Date 4/9/2019 Reference Rate and Spread E + 7.25% Interest Rate 9.45%2022-01-012022-12-310001508655Debt 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%2023-01-012023-12-310001508655Debt 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%2023-01-012023-12-310001508655Debt 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%2023-12-3100015086552013-12-310001508655Debt Investments Business services Acceo Solutions, Inc. First-lien loan (CAD 57,353 par, due 10/2025) Initial Acquisition Date 7/6/2018 Reference Rate and Spread C + 4.75% Interest Rate 9.49%2022-01-012022-12-310001508655Equity 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%2023-01-012023-12-310001508655Equity 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 L + 2.95% Interest Rate 5.66%2022-01-012022-12-310001508655Debt Investments Oil, Gas and Consumable Fuels TRP Assets, LLC First-lien loan ($57,818 par, due 12/2025) Initial Acquisition Date 12/3/2021 Reference Rate Spread SOFR + 7.76% Interest Rate 12.34%2022-01-012022-12-310001508655Debt Investments Healthcare Integrated Practice Solutions, Inc. First-lien loan ($46,312 par, due 10/2024) Initial Acquisition Date 6/30/2017 Reference Rate and Spread L + 7.50% Interest Rate 11.89%2022-12-310001508655Debt 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%2023-12-310001508655srt:MaximumMemberus-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMember2023-12-310001508655Debt Investments Business services ReliaQuest Holdings, LLC First-lien loan ($63,477 par, due 10/2026) Initial Acquisition Date 10/8/2020 Reference Rate and Spread SOFR + 7.25% Interest Rate 11.83%2022-12-310001508655Debt Investments, Transportation2023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:PassportLabsIncMember2023-12-310001508655Debt Investments Financial Services BTRS Holdings, Inc. First-lien loan ($45,180 par, due 12/2028) Initial Acquisition Date 12/16/2022 Reference Rate and Spread SOFR + 8.00% Interest Rate 12.50%2022-01-012022-12-310001508655Debt Investments Healthcare Caris Life Sciences, Inc. Convertible note ($2,602 par, due 9/2023) Initial Acquisition Date 9/21/2018 Reference Rate and Spread 8.00% Interest Rate 8.00%2022-12-310001508655Equity 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%2023-01-012023-12-310001508655Equity and Other Investments Structured Credit CarVal CLO III Ltd, Series 2019-2A Structured Product ($1,000 par, due 7/2032) Initial Acquisition Date 6/30/2022 Reference Rate and Spread L + 6.44% Interest Rate 9.15%2022-12-310001508655Equity and Other Investments Business Services Mitnick TA Aggregator, LP Membership Interest (0.43% ownership) Initial Acquisition Date 5/2/20222022-01-012022-12-310001508655tslx:SupplementalDividendMember2021-11-022021-11-020001508655Equity and Other Investments Oil, Gas and Consumable Fuels Murchison Oil and Gas, LLC 13,355 Preferred Units Initial Acquisition Date 6/30/20222022-12-310001508655Debt Investments Hotel, Internet Services EDB Parent, LLC First-lien loan ($56,963 par, due 7/2028) Initial Acquisition Date 7/7/2022 Reference Rate Spread SOFR + 7.00% Interest Rate 11.58%2022-01-012022-12-310001508655Interest Rate Swap Company Receives 3.875% Company Pays L + 2.46% Maturity Date 11/1/20242022-12-310001508655Interest Rate Swap Company Pays SOFR + 2.51% Maturity Date 11/1/20242023-12-310001508655Debt Investments Financial Services BTRS Holdings, Inc. First-lien loan ($1,205 par, due 12/2028) Initial Acquisition Date 12/16/2022 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.63%2023-12-310001508655tslx:BaseDividendMember2022-02-170001508655Equity 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 L + 2.95% Interest Rate 5.66%2022-12-310001508655tslx:FirstLienDebtInvestmentsMember2022-01-012022-12-310001508655tslx:InterestRateSwapSixMember2023-01-012023-12-310001508655tslx:OfficeProductsMember2023-12-310001508655Debt 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)2023-12-310001508655Equity and Other Investments Internet Services Lucidworks, Inc. Series F Preferred Shares (199,054 shares) Initial Acquisition Date 8/2/20192023-01-012023-12-310001508655tslx:SupplementalDividendMember2023-08-030001508655Debt 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, Manufacturing, Unsecured Note ($1,059 par, due 9/2029), Initial Acquisition Date 8/31/2023, Reference Rate and Spread, 7.50%, Interest Rate 7.50%2023-12-3100015086552022-07-012022-09-300001508655tslx:TwoThousandTwentySixNotesMemberus-gaap:InterestRateSwapMember2022-01-012022-12-310001508655Debt Investments Financial Services Passport Labs, Inc. First-lien loan ($23,390 par, due 4/2026) Initial Acquisition Date 4/28/2021 Reference Rate and Spread L + 8.25% Interest Rate 12.58% (incl. 4.125% PIK)2022-12-310001508655tslx:PharmaceuticalsMember2022-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:FullsteamOperationsLlcMember2023-12-310001508655Equity 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 Education EMS Linq, Inc. Class B Units (5,522,526 units) Initial Acquisition Date 12/22/20212022-12-310001508655tslx:DelayedDrawMembertslx:MurchisonOilAndGasLlcMember2022-12-310001508655tslx:LeverageWaiverMembertslx:InvestmentAdvisoryAgreementMember2022-01-012022-12-310001508655Equity and Other Investments Financial Services TradingScreen, Inc. Class A Units (600,000 units) Initial Acquisition Date 5/14/20212023-01-012023-12-310001508655Debt Investments Business services ExtraHop Networks, Inc. First-lien loan ($57,950 par, due 7/2027) Initial Acquisition Date 7/22/2021 Reference Rate and Spread L + 7.50% Interest Rate 12.23%2022-01-012022-12-310001508655Debt 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%2023-01-012023-12-310001508655tslx:OtherMember2022-12-310001508655Debt 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%2023-01-012023-12-310001508655tslx:RisksRelatedToOurPortfolioCompanyInvestmentsMember2023-01-012023-12-310001508655Interest Rate Swap Company Receives 4.50% Company Pays L + 199% Maturity Date 1/22/20232022-12-310001508655Debt Investments Human Resource Support Services PageUp People, Ltd. First-lien loan ($12,011 par, due 12/2025) Initial Acquisition Date 10/28/2021 Reference Rate and Spread L + 5.50% Interest Rate 10.65%2022-12-310001508655Equity 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 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%2023-01-012023-12-310001508655tslx:LeverageWaiverMembertslx:InvestmentAdvisoryAgreementMember2023-01-012023-12-310001508655tslx:SouthMember2023-12-310001508655tslx:MarketingServicesMember2023-12-310001508655Equity and Other Investments Retail and Consumer Products Neuintel, LLC Class A Units (1,176,494 units) Initial Acquisition Date 12/21/20212023-01-012023-12-310001508655tslx:TwoThousandTwentyTwoConvertibleNotesMember2021-01-012021-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:NetwrixCorpMember2023-12-310001508655tslx:TransportationMember2022-12-310001508655us-gaap:NondesignatedMember2023-12-310001508655tslx:CordanceOperationsLlcMembertslx:RevolverMember2022-12-310001508655tslx:BaseDividendMember2021-11-022021-11-020001508655country:CA2022-12-310001508655Equity and Other Investments Business Services ReliaQuest, LLC 90,634 Warrants Initial Acquisition Date 12/20/20232023-01-012023-12-3100015086552021-07-012021-09-300001508655Debt 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)2023-01-012023-12-310001508655Debt 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%2023-01-012023-12-310001508655tslx:RisksRelatedToOurSecuritiesMember2023-01-012023-12-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. Series C Preferred Shares (362,319 shares) Initial Acquisition Date 10/13/20202022-01-012022-12-310001508655Debt 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, Manufacturing, 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%2023-01-012023-12-310001508655tslx:TwoThousandTwentySixNotesMember2022-12-310001508655Equity 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%2023-12-310001508655tslx:TwoThousandTwentyTwoConvertibleNotesMember2022-01-262022-01-260001508655Equity and Other Investments Structured Credit Ares 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 L + 6.70% Interest Rate 9.21%2022-01-012022-12-310001508655country:NL2023-12-310001508655Equity 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 L + 6.20% Interest Rate 8.98%2022-12-310001508655tslx:DelayedDrawMembertslx:BCTOAcePurchaserIncMember2023-12-3100015086552022-04-012022-12-310001508655srt:MaximumMemberus-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:SecondLienDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMember2022-12-310001508655Equity and Other Investments Internet Services Piano Software, Inc. Series C-2 Preferred Shares (27,588 shares) Initial Acquisition Date 11/18/20222023-01-012023-12-3100015086552014-01-012014-12-310001508655Equity and Other Investments Structured Credit Bain Capital Credit CLO Ltd, Series 2018-1A Structured Product ($500 par, due 4/2031) Initial Acquisition Date 10/15/2020 Reference Rate and Spread L + 5.35% Interest Rate 8.13%2022-01-012022-12-310001508655Debt 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%2023-01-012023-12-310001508655tslx:SecondLienDebtInvestmentsMember2022-01-012022-12-310001508655tslx:LithiumTechnologiesLLCMembertslx:RevolverMember2022-12-310001508655us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InterestRateSwapMemberus-gaap:InterestExpenseMember2022-01-012022-12-310001508655Equity and Other Investments Business Services Sprinklr, Inc. Common Shares (315,005 shares) Initial Acquisition Date 6/24/20212023-12-310001508655Debt Investments Hotel, Internet Services Workwell CrunchTime Information, Systems, Inc First-lien loan ($53,121 par, due 6/2028) Initial Acquisition Date 6/17/2022 Reference Rate Spread SOFR + 6.00% Interest Rate 10.32%2022-12-310001508655Equity and Other Investments Internet Services SMA Technologies Holdings, LLC Class A Units (1,300 shares) Initial Acquisition Date 11/21/20222023-12-310001508655Equity and Other Investments Retail and Consumer Products Copper Bidco, LLC Trust Certificates (996,958 Certificates) Initial Acquisition Date 1/30/20212023-12-310001508655Debt Investments 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%2023-01-012023-12-310001508655Equity and Other Investments Internet Services SMA Technologies Holdings, LLC Class A Units (1,300 shares) Initial Acquisition Date 11/21/20222022-12-310001508655Equity and Other Investments Structured Credit Cedar Funding CLO Ltd, Series 2018-7A Structured Product ($1,000 par, due 1/2031) Initial Acquisition Date 7/21/2022 Reference Rate and Spread L + 4.55% Interest Rate 7.26%2022-01-012022-12-310001508655Debt Investments Hotel, Manufacturing Avalara, Inc First-lien loan ($38,636 par, due 10/2028) Initial Acquisition Date 10/19/2022 Reference Rate Spread SOFR + 7.25% Interest Rate 11.83%2022-12-310001508655Equity and Other Investments Oil, Gas and Consumable Fuels TRP Assets, LLC Partnership Interest (1.89% ownership) Initial Acquisition Date 8/25/20222022-12-310001508655Interest Rate Swap Company Receives 3.875% Company Pays L + 2.25% Maturity Date 11/1/20242022-12-310001508655Equity and Other Investments Human Resource Support Services Employment Hero Holdings Pty Ltd. Series E Preferred Shares (113,250 shares) Initial Acquisition Date 3/1/20222022-01-012022-12-310001508655Equity and Other Investments Education EMS Linq, Inc. Class B Units (5,522,526 units) Initial Acquisition Date 12/22/20212022-01-012022-12-310001508655Interest Rate Swap Company Receives L+2.28% Company Pays 3.875% Maturity Date 11/1/20242022-01-012022-12-310001508655us-gaap:DomesticCountryMember2023-01-012023-12-310001508655Equity and Other Investments Internet Services Bayshore Intermediate #2, L.P. Co-Invest 2 Common Units (3,493,701 units) Initial Acquisition Date 10/1/20212023-12-310001508655tslx:FirstLienDebtInvestmentsMember2021-12-310001508655tslx:BaseDividendMember2023-05-080001508655Debt 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%2023-12-3100015086552021-06-300001508655Equity and Other Investments Healthcare Merative Topco L.P. 989,691 Class A-1 Units Initial Acquisition Date 6/30/20222023-12-310001508655Debt 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%2023-01-012023-12-310001508655Debt 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)2023-12-310001508655tslx:FutureRealizedCapitalGainsPriorToAprilFirstTwoThousandFourteenMembertslx:InvestmentAdvisoryAgreementMember2020-03-310001508655tslx:BaseDividendMember2023-11-022023-11-020001508655Equity 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%2023-12-310001508655Debt 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 11.84%2022-12-310001508655Equity and Other Investments Business Services ReliaQuest, LLC Series A Preferred Sotck (1,667 Units) Initial Acquisition Date 12/20/20232023-12-310001508655Debt Investments Hotel, Internet Services Lithium Technologies, LLC First-lien revolving loan ($1,320 par, due 1/2024) Initial Acquisition Date 10/3/2017 Reference Rate Spread SOFR + 8.00% Interest Rate 12.06%2022-12-310001508655Equity and Other Investments Internet Services SMA Technologies Holdings, LLC Class B Units (923,250 shares) Initial Acquisition Date 11/21/20222023-01-012023-12-310001508655Equity 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%2023-01-012023-12-310001508655Equity and Other Investments Retail and Consumer Products Neuintel, LLC Class A Units (1,176,494 units) Initial Acquisition Date 12/21/20212023-12-310001508655Debt 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%2023-12-310001508655country:GB2022-12-310001508655Interest Rate Swap Company Pays L + 2.25% Maturity Date 11/1/20242022-12-310001508655Debt 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 S + 5.10% Interest Rate 10.45%2023-12-310001508655Debt 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%2023-12-310001508655Equity and Other Investments Hotel, Gaming and Leisure IRGSE Holding Corp. Class C-1 Units (8,800,000 units) Initial Acquisition Date 12/21/20182023-12-310001508655Equity and Other Investments Business Services ReliaQuest, LLC Class A-2 Units (2,989 units) Initial Acquisition Date 6/21/20222023-01-012023-12-310001508655tslx:OilGasAndConsumableFuelsMember2022-12-310001508655Equity and Other Investments Healthcare Raptor US Buyer II Corp. 20,268 Ordinary Shares Initial Acquisition Date 3/24/20232023-01-012023-12-310001508655Equity and Other Investments Retail and Consumer Products Copper Bidco, LLC Trust Certificates (996,958 Certificates) Initial Acquisition Date 1/30/20212022-01-012022-12-310001508655Debt 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 12.02%2023-01-012023-12-310001508655Debt Investments, Transportation, 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%2023-12-3100015086552021-12-310001508655tslx:NonControlledNonAffiliatedInvestmentsMember2021-01-012021-12-310001508655Debt 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%2023-01-012023-12-310001508655tslx:InternetServicesMember2022-12-310001508655Debt 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%2023-12-310001508655Debt 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% (PIK)2023-12-310001508655Equity and Other Investments Human Resource Support Services DaySmart Holdings, LLC Class A Units (166,811 units) Initial Acquisition Date 10/1/20192022-12-310001508655Equity and Other Investments Financial Services Newport Parent Holdings, L.P. Class A-2 Units (131,569 units) Initial Acquisition Date 12/10/20202023-12-310001508655Debt 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%2023-01-012023-12-310001508655Debt 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%2023-01-012023-12-3100015086552023-04-012023-06-300001508655Interest Rate Swap Company Receives 6.95% Company Pays SOFR + 2.99% Maturity Date 8/14/20282023-01-012023-12-310001508655Equity 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%2023-01-012023-12-310001508655Debt 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%2023-01-012023-12-310001508655tslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputComparabilityAdjustmentMemberus-gaap:MarketApproachValuationTechniqueMember2023-12-310001508655tslx:MarketingServicesMember2022-12-310001508655tslx:TwoThousandTwentyEightNotesMember2023-08-142023-08-140001508655Interest Rate Swap Company Receives 2.50% Company Pays SOFR + 2.17% Maturity Date 8/1/20262023-12-310001508655Debt Investments Communications IntelePeer Holdings, Inc. First-lien loan ($34,677 par, due 12/2024) Initial Acquisition date 12/2/2019 Reference Rate and Spread L + 8.25% Interest Rate 12.63%2022-01-012022-12-3100015086552021-01-012021-12-310001508655Equity and Other Investments Human Resource Support Services Axonify, Inc . Class A-1 Units (3,780,000 units) Initial Acquisition Date 5/5/20212022-01-012022-12-310001508655tslx:TwentyTwentySixNotesMember2021-02-032021-02-0300015086552022-10-012022-12-310001508655Debt 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 12.60%2023-01-012023-12-310001508655Debt 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%2023-01-012023-12-310001508655tslx:TwoThousandTwentyFourNotesMember2019-11-012019-11-300001508655Debt Investments Hotel, Internet Services Workwell Bayshore Intermediate #2, L. First-lien loan ($32,194 par, due 10/2028) Initial Acquisition Date 10/1/2021 Reference Rate Spread L + 7.75% Interest Rate 12.04% PIK2022-12-310001508655Debt 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 8.26%2022-01-012022-12-310001508655Equity 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%2023-12-310001508655tslx:InterestRateSwapFourMember2023-01-012023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:ForeScoutTechnologiesIncMember2023-12-310001508655Debt Investments Business Services Netwrix Corp First-lien loan ($36,594 par, due 6/2029) Initial Acquisition Date 6/9/2022 Reference Rate and Spread SOFR + 5.00% Interest Rate 10.39%2023-12-310001508655Interest Rate Swap3 Company Receives L + 2.11% Maturity Date 8/1/20222022-12-310001508655tslx:StructuredCreditInvestmentsMember2023-12-310001508655Debt 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%2023-01-012023-12-310001508655Debt 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%2023-01-012023-12-310001508655Equity 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%2023-01-012023-12-310001508655tslx:MezzanineDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Member2023-01-012023-12-310001508655Interest Rate Swap Company Receives 6.95% Company Pays SOFR + 2.99% Maturity Date 8/14/20282023-12-310001508655Equity 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 Internet Services SMA Technologies Holdings, LLC Class A Units (1,300 shares) Initial Acquisition Date 11/21/20222022-01-012022-12-310001508655Equity and Other Investments Structured Credit Ares CLO Ltd, Series 2021-59A Structured Product ($1,000 par, due 4/2034) Initial Acquisition Date 6/23/2022 Reference Rate and Spread L + 6.25% Interest Rate 9.03%2022-01-012022-12-310001508655country:NO2022-12-3100015086552023-05-150001508655us-gaap:RevolvingCreditFacilityMembersrt:MaximumMember2022-12-310001508655tslx:RevolvingCreditsFacilitiesMember2017-12-310001508655Debt 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)2023-12-310001508655Debt 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:NortheastMember2023-12-310001508655Equity 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 L + 5.75% Interest Rate 8.26%2022-12-310001508655Equity 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%2023-01-012023-12-310001508655Equity 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 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:AssetValuationWaterfallMembertslx:MezzanineDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Member2023-12-310001508655tslx:TwoThousandTwentySixNotesMember2023-01-012023-12-310001508655us-gaap:IncomeApproachValuationTechniqueMembertslx:MezzanineDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputDiscountRateMember2023-12-310001508655Debt Investments Financial Services BTRS Holdings, Inc. First-lien loan ($45,180 par, due 12/2028) Initial Acquisition Date 12/16/2022 Reference Rate and Spread SOFR + 8.00% Interest Rate 12.50%2022-12-310001508655Equity 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 Human Resource Support Services PageUp People, Ltd. First-lien loan ($12,011 par, due 12/2025) Initial Acquisition Date 10/28/2021 Reference Rate and Spread L + 5.50% Interest Rate 10.65%2022-01-012022-12-310001508655Interest Rate Swap Company Pays SOFR + 2.17% Maturity Date 8/1/20262023-12-310001508655Interest Rate Swap, Cash collateral2023-12-310001508655tslx:DelayedDrawMembertslx:BctoBluebillBuyerIncMember2023-12-310001508655Debt 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%2023-01-012023-12-310001508655Debt Investments Healthcare Caris Life Sciences, Inc. First-lien loan ($3,750 par, due 4/2025) Initial Acquisition Date 4/2/2020 Reference Rate and Spread 11.30% Interest Rate 11.30%2022-01-012022-12-310001508655Debt 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 12.03% (incl. 6.50% PIK)2023-01-012023-12-310001508655tslx:InterestRateSwapFiveMember2022-01-012022-12-310001508655tslx:ManufacturingMember2023-12-310001508655us-gaap:RevolvingCreditFacilityMembersrt:MinimumMember2023-01-012023-12-310001508655Equity 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%2023-12-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. 633,376 Warrants Initial Acquisition Date 9/21/20182022-12-310001508655Non-controlled Affiliated Investments MD America Energy, LLC2021-12-310001508655Debt 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 Internet Services SMA Technologies Holdings, LLC Class B Units (923,250 shares) Initial Acquisition Date 11/21/20222022-12-310001508655Debt Investments Hotel, Gaming and Leisure2022-12-310001508655Debt Investments Hotel, Internet Services Lithium Technologies, LLC First-lien revolving loan ($1,320 par, due 1/2024) Initial Acquisition Date 10/3/2017 Reference Rate Spread SOFR + 8.00% Interest Rate 12.06%2022-01-012022-12-310001508655tslx:ConvertibleSeniorNotesDueTwentyNineteenMember2015-12-310001508655Debt 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% PIK2023-01-012023-12-310001508655srt:MaximumMembertslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputComparabilityAdjustmentMemberus-gaap:MarketApproachValuationTechniqueMember2022-12-310001508655Debt Investments, Transportation, Project44, Inc, First-lien revolving loan ($35,139 par, due 11/2027), Initial Acquisition Date 11/12/2021, Reference Rate and Spread, SOFR + 6.40%, Interest Rate 11.78%2023-12-3100015086552023-01-012023-12-310001508655Equity 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%2023-01-012023-12-310001508655Debt Investments Retail and Consumer Products American Achievement, Corp. First-lien loan ($1,363 par, due 9/2026) Initial Acquisition Date 6/10/2021 Reference Rate and Spread L + 14.00 % Interest Rate 18.13% (incl. 17.63% PIK)2022-12-310001508655Debt Investments, Manufacturing, Unsecured Note ($1,059 par, due 9/2029), Initial Acquisition Date 8/31/2023, Reference Rate and Spread, 7.50%, Interest Rate 7.50%2023-01-012023-12-310001508655Debt 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%2023-01-012023-12-310001508655Debt Investments Healthcare2023-12-310001508655Debt 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 12.03% (incl. 3.25% PIK)2023-12-310001508655Equity and Other Investments Business Services ReliaQuest, LLC 90,634 Warrants Initial Acquisition Date 12/20/20232023-12-310001508655Equity 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 L + 2.60% Interest Rate 5.11%2022-01-012022-12-310001508655tslx:ValuationTechniqueCostOfInvestmentsMembertslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Member2023-12-310001508655Debt Investments Business services Dye & Durham Corp. First-lien loan (CAD 34,220 par, due 12/2027) Initial Acquisition Date 12/3/2021 Reference Rate and Spread C + 5.75% Interest Rate 10.69%2022-01-012022-12-310001508655us-gaap:SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMembertslx:TwoThousandTwentyEightNotesMember2023-01-012023-12-310001508655Equity and Other Investments Education RMCF IV CIV XXXV, LP. Partnership Interest (11.94% ownership) Initial Acquisition Date 6/8/20212022-12-310001508655Interest Rate Swap, Cash collateral2022-12-310001508655Debt 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%2023-12-310001508655tslx:TwentyTwentyTwoConvertibleNotesMember2017-02-012017-02-280001508655Debt 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 10.02%2022-01-012022-12-310001508655tslx:SupplementalDividendMember2023-11-020001508655tslx:TwentyTwentyFourNotesMember2021-12-310001508655tslx:CrunchtimeInformationSystemsIncMembertslx:DelayedDrawMember2022-12-310001508655Debt 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 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%2023-01-012023-12-3100015086552022-06-300001508655us-gaap:AdditionalPaidInCapitalMember2021-01-012021-12-310001508655us-gaap:FairValueInputsLevel3Member2022-12-310001508655tslx:TwoThousandTwentySixNotesMemberus-gaap:SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember2023-09-252023-09-250001508655Equity and Other Investments Structured Credit Battalion CLO Ltd, Series 2021-21A Structured Product ($1,300 par, due 7/2034) Initial Acquisition Date 7/13/2022 Reference Rate and Spread L + 3.30% Interest Rate 5.81%2022-01-012022-12-310001508655Debt 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:TwoThousandTwentyThreeNotesMember2018-01-310001508655tslx:TwoThousandTwentySixNotesMemberus-gaap:InterestRateSwapMember2023-01-012023-12-310001508655Equity and Other Investments Healthcare Merative L.P. 989,691 Class A-1 Units Initial Acquisition Date 6/30/20222022-01-012022-12-310001508655Debt 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%2023-12-310001508655tslx:MezzanineDebtInvestmentsMember2022-01-012022-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:TangoManagementConsultingLLCMember2022-12-310001508655Derivative Interest Rate Swap2023-01-012023-12-310001508655Debt 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%2023-12-310001508655tslx:MezzanineDebtInvestmentsMember2022-12-310001508655tslx:InterestRateSwapTenMember2022-01-012022-12-310001508655tslx:SupplementalDividendMember2021-05-040001508655Equity 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%2023-01-012023-12-310001508655Equity and Other Investments Education2022-12-310001508655Equity 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 L + 6.25% Interest Rate 8.96%2022-12-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. 280,000 Warrants Initial Acquisition Date 2/28/20202022-12-310001508655Debt 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)2023-12-3100015086552023-06-300001508655Equity and Other Investments Structured Credit Signal Peak CLO LLC, Series 2018-5A Structured Product ($1,000 par, due 4/2031) Initial Acquisition Date 8/9/2022 Reference Rate and Spread L + 5.65% Interest Rate 8.43%2022-12-3100015086552023-07-012023-09-300001508655Equity and Other Investments Structured Credit Benefit Street Partners CLO Ltd, Series 2015-BR Structured Product ($2,500 par, due 7/2034) Initial Acquisition Date 7/13/2022 Reference Rate and Spread L + 3.85% Interest Rate 6.56%2022-12-310001508655us-gaap:RevolvingCreditFacilityMemberus-gaap:BaseRateMembersrt:MinimumMember2023-12-310001508655tslx:BaseDividendMember2021-02-170001508655Equity 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 L + 6.20% Interest Rate 8.98%2022-01-012022-12-310001508655Controlled Affiliated Investments IRGSE Holding Corp.2023-01-012023-12-310001508655Equity and Other Investments Human Resource Support Services2022-12-310001508655tslx:MidwestMember2022-12-310001508655tslx:RealizedCapitalGainsAccruedBeginningAprilFirstTwoThousandFourteenMembertslx:InvestmentAdvisoryAgreementMember2011-04-152011-04-150001508655Debt Investments Healthcare BCTO Ace Purchaser, Inc. First-lien loan ($63,565 par, due 11/2026) Initial Acquisition Date 11/23/2020 Reference Rate and Spread SOFR + 7.70% Interest Rate 12.10 %2022-01-012022-12-310001508655srt:MaximumMemberus-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:SecondLienDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMember2023-12-310001508655tslx:BaseDividendMember2021-02-172021-02-170001508655us-gaap:OverAllotmentOptionMember2023-06-120001508655Debt Investments Financial Services Ibis Intermediate Co. First-lien loan ($1,526 par, due 5/2027) Initial Acquisition Date 5/28/2021 Reference Rate and Spread L + 5.00% Interest Rate 9.73%2022-01-012022-12-310001508655Debt Investments Human Resource Support Services Workwell Acquisition Co. First-lien loan ($23,798 par, due 10/2025) Initial Acquisition Date 10/19/2020 Reference Rate and Spread SOFR + 7.40% Interest Rate 11.38%2022-01-012022-12-310001508655tslx:FirstLienDebtInvestmentsMember2023-01-012023-12-310001508655tslx:RevolverMembertslx:DiscoParentIncMember2023-12-310001508655Equity 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 L + 6.60% Interest Rate 9.11%2022-01-012022-12-310001508655tslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel2Member2022-12-310001508655Debt 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%2023-12-310001508655us-gaap:LetterOfCreditMember2023-12-310001508655Equity 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%2023-01-012023-12-310001508655Equity and Other Investments Retail and Consumer Products American Achievement, Corp. Class A Units (687 units) Initial Acquisition Date 3/16/20212023-12-310001508655tslx:TwoThousandTwentyEightNotesMember2023-08-140001508655Debt 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:TwoThousandTwentyFourNotesMember2022-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:BtrsHoldingIncMember2022-12-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. 106,592 Warrants Initial Acquisition Date 4/8/20212022-01-012022-12-310001508655tslx:ManufacturingMember2022-12-310001508655Equity 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%2023-12-310001508655Equity and Other Investments Internet Services2023-12-310001508655tslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel2Member2023-12-310001508655us-gaap:FairValueInputsLevel3Membertslx:SecondLienDebtInvestmentsMember2022-12-310001508655Debt 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%2023-01-012023-12-310001508655Equity and Other Investments Financial Services Newport Parent Holdings, LP Class A-2 Units (131,569 units) Initial Acquisition Date 12/10/20202022-12-310001508655Interest Rate Swap Company Receives 4.50% Maturity Date 8/1/20222022-12-310001508655Debt Investments Hotel, Internet Services Workwell CrunchTime Information, Systems, Inc First-lien loan ($53,121 par, due 6/2028) Initial Acquisition Date 6/17/2022 Reference Rate Spread SOFR + 6.00% Interest Rate 10.32%2022-01-012022-12-3100015086552022-01-012022-03-310001508655Debt Investments Communications IntelePeer Holdings, Inc. First-lien loan ($34,677 par, due 12/2024) Initial Acquisition date 12/2/2019 Reference Rate and Spread L + 8.25% Interest Rate 12.63%2022-12-310001508655Debt 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%2023-01-012023-12-3100015086552023-09-300001508655Equity 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 L + 3.52% Interest Rate 6.23%2022-12-310001508655Debt 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%2023-12-310001508655Equity and Other Investments Hotel, Gaming and Leisure IRGSE Holding Corp. Class C-1 Units (8,800,000 units) Initial Acquisition Date 12/21/20182022-01-012022-12-310001508655Equity 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%2023-12-310001508655Equity and Other Investments Internet Services Bayshore Intermediate #2, L.P. Common Units (12,330,709 units) Initial Acquisition Date 10/1/20212022-01-012022-12-310001508655Equity 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 L + 2.85% Interest Rate 5.36%2022-01-012022-12-310001508655Debt Investments2023-12-310001508655Debt Investments Business services TIBCO Software Inc. First-lien note ($13,000 par, due 3/2029) Initial Acquisition Date 9/20/2022 Reference Rate and Spread 6.50% Interest Rate 6.5%2022-01-012022-12-310001508655Equity and Other Investments Structured Credit Gulf Stream Meridian, Series 2021-6A Structured Product ($2,000 par, due 1/2037) Initial Acquisition Date 9/12/2022 Reference Rate and Spread L + 6.36% Interest Rate 8.87%2022-12-310001508655Interest Rate Swap Company Pays 4.50% Maturity Date 8/1/20222022-12-310001508655Equity and Other Investments Human Resource Support Services Bswift LLC Class A-1 Units (2,393,509 units) Initial Acquisition Date 11/7/20222022-12-310001508655Debt Investments Retail and Consumer Products American Achievement, Corp. First-lien loan ($27,171 par, due 9/2026) Initial Acquisition Date 9/30/2015 Reference Rate and Spread L + 6.25 % Interest Rate 10.38% (incl. 9.88% PIK)2022-12-310001508655Debt 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 Healthcare Merative L.P. 989,691 Class A-1 Units Initial Acquisition Date 6/30/20222022-12-310001508655tslx:BaseDividendMember2023-02-162023-02-160001508655Equity 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 L + 6.58% Interest Rate 9.35%2022-01-012022-12-310001508655Debt Investments Human Resource Support Services Modern Hire, Inc First-lien loan ($28,878 par, due 5/2024) Initial Acquisition Date 5/15/2019 Reference Rate and Spread L + 7.00% Interest Rate 11.38%2022-01-012022-12-310001508655us-gaap:AdditionalPaidInCapitalMember2021-12-310001508655tslx:LeverageWaiverMembertslx:InvestmentAdvisoryAgreementMember2011-04-152011-04-150001508655Equity and Other Investments Structured Credit Benefit Street Partners CLO Ltd, Series 2015-8A Structured Product ($1,425 par, due 1/2031) Initial Acquisition Date 9/13/2022 Reference Rate and Spread L + 2.75% Interest Rate 5.46%2022-12-310001508655Debt Investments Mach Resource, First-lien loan ($5,000 par, due 12/2026) Initial Acquisition Date 12/28/2023 Reference Rate and Spread SOFR + 6.50% Interest Rate 12.00%2023-12-310001508655Equity and Other Investments Internet Services Lucidworks, Inc. Series F Preferred Shares (199,054 shares) Initial Acquisition Date 8/2/20192023-12-310001508655Debt 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 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%2023-12-310001508655Debt 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%2023-12-310001508655Debt Investments Communications2023-12-310001508655Equity and Other Investments Oil, Gas and Consumable Fuels Murchison Oil and Gas, LLC 13,355 Preferred Units Initial Acquisition Date 6/30/20222023-01-012023-12-310001508655Debt 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)2023-01-012023-12-310001508655Equity and Other Investments Structured Credit Carlyle Global Market Strategies CLO Ltd, Series 2014-4RA Structured Product ($1,000 par, due 7/2030) Initial Acquisition Date 3/26/2022 Reference Rate and Spread L + 2.90% Interest Rate 5.41%2022-12-310001508655Equity and Other Investments Structured Credit Eaton CLO Ltd, Series 2020-1A Structured Product ($1,000 par, due 10/2034) Initial Acquisition Date 8/11/2022 Reference Rate and Spread L + 6.25% Interest Rate 8.76%2022-12-310001508655Equity 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%2023-12-310001508655Debt Investments Financial Services BlueSnap, Inc. First-lien loan ($42,000 par, due 10/2024) Initial Acquisition Date 10/25/2019 Reference Rate and Spread L + 6.75% Interest Rate 11.48%2022-12-310001508655tslx:StructuredCreditInvestmentsMember2022-12-310001508655Equity 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%2023-12-310001508655Equity and Other Investments Hotel, Gaming and Leisure IRGSE Holding Corp. Class A Units (33,790,171 units) Initial Acquisition Date 12/21/20182023-12-310001508655Hedge Accounting Swaps2023-12-310001508655Debt Investments Human Resource Support Services2023-12-310001508655Equity and Other Investments Retail and Consumer Products Copper Bidco, LLC Trust Certificates (132,928 Certificates) Initial Acquisition Date 12/7/20202023-01-012023-12-310001508655Debt 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%2023-01-012023-12-310001508655us-gaap:RevolvingCreditFacilityMember2023-01-012023-12-310001508655Equity and Other Investments Financial Services2022-12-310001508655tslx:NonControlledNonAffiliatedInvestmentsMember2022-12-310001508655srt:MaximumMembertslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputComparabilityAdjustmentMemberus-gaap:MarketApproachValuationTechniqueMember2023-12-310001508655Debt Investments Hotel, Gaming and Leisure IRGSE Holding Corp First-lien loan ($30,261 par, due 6/2023) Initial Acquisition Date 9/29/2015 Reference Rate and Spread L + 9.50% Interest Rate 14.19%2022-12-310001508655Non Hedge Accounting Swaps2022-12-310001508655Debt Investments Retail and Consumer Products Tango Management Consulting, LLC First-lien loan ($44,674 par, due 12/2027) Initial Acquisition Date 12/1/2021 Reference Rate and Spread L + 6.75% Interest Rate 10.49%2022-01-012022-12-310001508655us-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMember2022-12-310001508655Debt 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%2023-01-012023-12-310001508655us-gaap:DomesticCountryMember2023-12-310001508655Debt Investments Business services TIBCO Software Inc. First-lien loan ($12,000 par, due 3/2029) Initial Acquisition Date 9/20/2022 Reference Rate and Spread SOFR + 4.60% Interest Rate 9.19%2022-01-012022-12-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. Series C Preferred Shares (1,816,295 shares) Initial Acquisition Date 4/8/20212023-01-012023-12-310001508655Equity 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 8.36%2023-12-3100015086552019-01-012019-12-310001508655Debt Investments Automotive Carlstar Group, LLC First-lien loan ($33,575 par, due 7/2027) Initial Acquisition Date 7/8/2022 Reference Rate and Spread SOFR + 6.60% Interest Rate 10.92%2022-12-310001508655Equity and Other Investments Retail and Consumer Products Neuintel, LLC Class A Units (1,176,494 units) Initial Acquisition Date 12/21/20212022-01-012022-12-310001508655Debt Investments, Transportation, 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 Retail and Consumer Products Project P Intermediate 2, LLC ABL FILO term loan ($73,125 par, due 5/2026) Initial Acquisition Date 11/8/2021 Reference Rate and Spread L + 8.00% Interest Rate 12.41%2022-12-310001508655Equity 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 L + 5.25% Interest Rate 7.76%2022-12-310001508655tslx:SupplementalDividendMember2023-08-032023-08-030001508655tslx:TwoThousandTwentyFourNotesMember2020-02-052020-02-050001508655tslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Member2022-12-310001508655Debt 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:DelayedDrawMembertslx:EDBParentLLCMember2022-12-310001508655Debt Investments Internet Services2023-12-310001508655Debt Investments Business services Netwrix Corp. First-lien loan ($36,119 par, due 6/2029) Initial Acquisition Date 6/9/2022 Reference Rate and Spread SOFR + 5.00% Interest Rate 9.7%2022-12-310001508655tslx:TwoThousandTwentyTwoConvertibleNotesMember2018-06-300001508655tslx:DelayedDrawAndRevolverMembertslx:PassportLabsIncMember2022-12-310001508655Debt Investments Human Resource Support Services Elysian Finco Ltd First-lien loan ($17,314 par, due 1/2028) Initial Acquisition Date 1/31/2022 Reference Rate and Spread SOFR + 6.65% Interest Rate 10.99%2022-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:ErlingLuxBidcoSarlMember2022-12-310001508655Debt 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 11.26%2023-01-012023-12-3100015086552021-03-310001508655tslx:ConvertibleSeniorNotesDueTwentyTwentyTwoMember2019-12-310001508655tslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Member2022-01-012022-12-310001508655tslx:TwoThousandTwentySixNotesMember2023-12-310001508655Hedge Accounting Swaps2023-01-012023-12-310001508655tslx:TwentyTwentyThreeNotesMember2018-12-310001508655tslx:DelayedDrawMembertslx:AxonifyIncMember2022-12-310001508655Equity 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 8.51%2023-12-310001508655tslx:ConvertibleSeniorNotesDueTwentyNineteenMember2014-12-310001508655tslx:MezzanineDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Member2022-01-012022-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:ForeScoutTechnologiesIncMember2022-12-310001508655tslx:TwoThousandTwentyFourNotesMemberus-gaap:InterestRateSwapMember2022-01-012022-12-310001508655Debt Investments Oil, Gas and Consumable Fuels Murchison Oil and Gas, LLC First-lien loan ($26,873 par, due 6/2026) Initial Acquisition Date 6/30/2022 Reference Rate Spread SOFR + 8.65% Interest Rate 13.23%2022-12-310001508655Debt 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%2023-01-012023-12-310001508655Equity 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 L + 5.25% Interest Rate 7.76%2022-01-012022-12-310001508655Derivative Interest Rate Swap2022-12-310001508655tslx:TwoThousandTwentyThreeTwentyFourTwentySixAndTwentyEightNotesMember2022-01-012022-12-310001508655tslx:WestMember2023-12-310001508655Equity and Other Investments Business Services Dye & Durham, Ltd. Common Shares (126,968 shares) Initial Acquisition Date 12/3/20212023-01-012023-12-310001508655Controlled Affiliated Investments IRGSE Holding Corp.2021-12-310001508655Non Hedge Accounting Swaps2022-01-012022-12-310001508655Equity and Other Investments Internet Services Piano Software, Inc. Series C-2 Preferred Shares (27,588 shares) Initial Acquisition Date 11/18/20222022-01-012022-12-310001508655Equity and Other Investments Pharmaceuticals2022-12-310001508655us-gaap:FairValueInputsLevel1Member2023-12-310001508655srt:MaximumMemberus-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMember2022-12-310001508655Equity 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%2023-01-012023-12-310001508655Debt Investments Hotel, Internet Services LeanTaaS Holdings, Inc. First-lien loan ($27,782 par, due 7/2028) Initial Acquisition Date 7/12/2022 Reference Rate Spread SOFR + 7.50% Interest Rate 12.08%2022-01-012022-12-310001508655Equity 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 Hotel, Internet Services Lucidworks, Inc. First-lien loan ($8,330 par, due 2/2027) Initial Acquisition Date 2/11/2022 Reference Rate Spread SOFR + 7.50% Interest Rate 11.82% (incl. 3.50% PIK)2022-01-012022-12-310001508655Interest Rate Swap Company Pays L + 1.60% Maturity Date 8/1/20222022-12-310001508655Equity 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 9.20%2023-01-012023-12-310001508655Equity and Other Investments Business Services Sprinklr, Inc. Common Shares (484,700 shares) Initial Acquisition Date 6/24/20212022-12-310001508655Equity and Other Investments Financial Services AvidXchange, Inc. Common Shares (200,721 shares) Initial Acquisition Date 10/15/20212022-12-310001508655Equity 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 L + 3.52% Interest Rate 6.23%2022-01-012022-12-310001508655Debt 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 Financial Services Kyriba Corp. First-lien loan ($19,051 par, due 4/2025) Initial Acquisition Date 4/9/2019 Reference Rate and Spread L + 9.00% Interest Rate 13.73% (incl. 9.00% PIK)2022-12-310001508655us-gaap:CommonStockMember2023-12-310001508655Equity and Other Investments Structured Credit Wind River CLO Ltd, Series 2017-1A Structured Product ($3,000 par, due 4/2036) Initial Acquisition Date 7/14/2022 Reference Rate and Spread L + 3.72% Interest Rate 6.46%2022-01-012022-12-310001508655Debt Investments Human Resource Support Services Workwell Acquisition Co. First-lien loan ($23,798 par, due 10/2025) Initial Acquisition Date 10/19/2020 Reference Rate and Spread SOFR + 7.40% Interest Rate 11.38%2022-12-310001508655us-gaap:InvestmentAffiliatedIssuerControlledMember2023-01-012023-12-310001508655tslx:HotelGamingAndLeisureMember2023-12-3100015086552015-01-012015-12-310001508655Equity 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%2023-12-310001508655tslx:BaseDividendMember2022-11-012022-11-010001508655tslx:SpecialDividendMember2021-02-170001508655tslx:RevolverMembertslx:WranglerTopcoLlcMember2023-12-310001508655tslx:MezzanineDebtInvestmentsMemberus-gaap:FairValueInputsLevel2Member2023-12-310001508655tslx:DelayedDrawMembertslx:OutsystemsLuxcoMember2022-12-310001508655tslx:CommunicationsMember2022-12-310001508655tslx:RevolvingCreditsFacilitiesMember2020-12-310001508655Equity and Other Investments Internet Services Piano Software, Inc. Series C-2 Preferred Shares (27,588 shares) Initial Acquisition Date 11/18/20222022-12-310001508655tslx:InterestRateSwapElevenMember2022-01-012022-12-310001508655Debt 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%2023-12-310001508655tslx:DelayedDrawMembertslx:LucidworksIncMember2022-12-310001508655Controlled Affiliated Investments2021-12-310001508655tslx:EquityAndOtherInvestmentsMember2022-01-012022-12-310001508655tslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Member2022-01-012022-12-310001508655Debt 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%2023-12-310001508655Debt 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 S + 5.10% Interest Rate 10.45%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%2023-12-3100015086552021-04-012021-06-300001508655Debt 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%2023-01-012023-12-310001508655tslx:StructuredCreditInvestmentsMember2022-01-012022-12-310001508655Interest Rate Swap Company Pays 3.875% Maturity Date 11/1/20242022-12-310001508655Debt 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 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%2023-01-012023-12-310001508655Equity and Other Investments Hotel, Gaming and Leisure2023-12-310001508655Debt 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:RetailAndConsumerProductsMember2023-12-310001508655Equity and Other Investments Pharmaceuticals TherapeuticsMD, Inc. 14,256 Warrants Initial Acquisition Date 8/5/20202022-01-012022-12-310001508655Debt 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% (PIK)2023-12-310001508655tslx:DelayedDrawMembertslx:Project44IncMember2023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:ErlingLuxBidcoSarlMember2023-12-310001508655Equity and Other Investments Structured Credit Ares Loan Funding I Ltd, Series 2021-ALFA, Class E StructuredProduct ($1,000par,due10/2034) Initial Acquisition Date 6/24/2022 Reference Rate and Spread SOFR+6.96% Interest Rate 12.36%2023-12-310001508655Controlled Affiliated Investments2022-12-310001508655tslx:SupplementalDividendMember2021-08-030001508655Debt Investments Business services ForeScout Technologies, Inc. First-lien loan ($6,502 par, due 8/2026) Initial Acquisition Date 8/17/2020 Reference Rate and Spread L + 9.50% Interest Rate 14.23% (incl. 9.50% PIK)2022-01-012022-12-310001508655Equity and Other Investments Financial Services TradingScreen, Inc. Class A Units (600,000 units) Initial Acquisition Date 5/14/20212023-12-310001508655tslx:PingIdentityCorporationMembertslx:RevolverMember2023-12-310001508655Debt 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%2023-12-3100015086552014-12-310001508655Debt Investments Oil, Gas and Consumable Fuels Murchison Oil and Gas, LLC First-lien loan ($26,873 par, due 6/2026) Initial Acquisition Date 6/30/2022 Reference Rate Spread SOFR + 8.65% Interest Rate 13.23%2022-01-012022-12-310001508655Equity and Other Investments Business Services ReliaQuest, LLC Series A Preferred Sotck (1,667 Units) Initial Acquisition Date 12/20/20232023-01-012023-12-310001508655tslx:RevolverMembertslx:AvalaraIncMember2022-12-310001508655tslx:RevolvingCreditsFacilitiesMember2019-12-310001508655Equity 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 Financial Services Kyriba Corp. First-lien revolving loan ($1,411 par, due 4/2025) Initial Acquisition Date 4/9/2019 Reference Rate and Spread L + 7.25% Interest Rate 11.98%2022-01-012022-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:EdgeBidcoBVMember2023-12-310001508655Equity and Other Investments Business Services Dye & Durham, Ltd. Common Shares (126,968 shares) Initial Acquisition Date 12/3/20212022-01-012022-12-310001508655Debt Investments Financial Services BlueSnap, Inc. First-lien loan ($42,000 par, due 10/2024) Initial Acquisition Date 10/25/2019 Reference Rate and Spread L + 6.75% Interest Rate 11.48%2022-01-012022-12-310001508655Equity and Other Investments Internet Services Piano Software, Inc. Series C-2 Preferred Shares (27,588 shares) Initial Acquisition Date 11/18/20222023-12-310001508655Equity and Other Investments Structured Credit Wind River CLO Ltd, Series 2014-2A Structured Product ($1,500 par, due 1/2031) Initial Acquisition Date 6/23/2022 Reference Rate and Spread L + 2.90% Interest Rate 5.41%2022-01-012022-12-310001508655Equity and Other Investments Human Resource Support Services Axonify, Inc . Class A-1 Units (3,780,000 units) Initial Acquisition Date 5/5/20212022-12-310001508655tslx:SecondLienDebtInvestmentsMember2023-01-012023-12-310001508655tslx:TwoThousandTwentyThreeNotesMembertslx:ThreeMonthLiborMember2022-01-012022-12-3100015086552023-03-310001508655Equity and Other Investments Business Services Mitnick TA Aggregator, LP Membership Interest (0.43% ownership) Initial Acquisition Date 5/2/20222022-12-310001508655Equity and Other Investments Business Services Sprinklr, Inc. Common Shares (484,700 shares) Initial Acquisition Date 6/24/20212022-01-012022-12-3100015086552023-10-012023-12-310001508655us-gaap:AdditionalPaidInCapitalMember2023-12-310001508655Equity 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%2023-01-012023-12-310001508655Debt Investments Chemicals Erling Lux Bidco SARL First-lien loan (GBP 10,217 par, due 9/2028) Initial Acquisition Date 9/6/2022 Reference Rate and Spread S + 6.75% Interest Rate 10.20%2022-12-310001508655Debt 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%2023-12-310001508655us-gaap:TreasuryStockCommonMember2023-12-310001508655tslx:TwentyTwentyFourNotesMember2022-12-310001508655us-gaap:CommonStockMember2021-12-310001508655Debt Investments Human Resource Support Services PayScale Holdings, Inc. First-lien loan ($68,775 par, due 5/2024) Initial Acquisition Date 5/3/2019 Reference Rate and Spread L + 5.75% Interest Rate 10.48%2022-12-310001508655tslx:FutureRealizedCapitalGainsPriorToAprilFirstTwoThousandFourteenMembertslx:InvestmentAdvisoryAgreementMember2020-03-312020-03-310001508655Equity and Other Investments Internet Services Bayshore Intermediate #2, L.P. Co-Invest Common Units (8,837,008 units) Initial Acquisition Date 10/1/20212023-12-310001508655tslx:SecondLienDebtInvestmentsMember2023-12-310001508655Interest Rate Swap Company Pays L + 1.91% Maturity Date 8/1/20262022-12-310001508655Equity 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%2023-12-310001508655tslx:AlaskaBidcoOyMembertslx:DelayedDrawAndRevolverMember2023-12-310001508655tslx:MezzanineDebtInvestmentsMember2022-01-012022-12-310001508655tslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputComparabilityAdjustmentMemberus-gaap:MarketApproachValuationTechniqueMembersrt:WeightedAverageMember2023-12-310001508655Debt 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 12.11%2023-12-310001508655us-gaap:CommonStockMember2021-02-230001508655tslx:PrimeRevenueIncMembertslx:RevolverMember2023-12-310001508655Equity 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 L + 3.05% Interest Rate 6.06%2022-01-012022-12-310001508655tslx:AdviserMemberus-gaap:GeneralAndAdministrativeExpenseMembertslx:AdministrationAgreementMember2022-01-012022-12-310001508655Interest Rate Swap Company Receives 2.50% Maturity Date 8/1/20262022-12-310001508655Equity 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 11.93%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 8.73%2022-01-012022-12-310001508655us-gaap:RetainedEarningsMember2023-01-012023-12-310001508655tslx:EducationMember2023-12-310001508655Equity 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 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%2023-01-012023-12-310001508655us-gaap:RevolvingCreditFacilityMember2023-06-120001508655Equity 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 L + 6.05% Interest Rate 8.76%2022-12-310001508655tslx:TwentyTwentyThreeNotesMember2022-12-310001508655Equity and Other Investments Hotel, Gaming and Leisure2022-12-3100015086552020-12-310001508655tslx:ConvertibleSeniorNotesDueTwentyNineteenMember2017-12-310001508655Interest Rate Swap2 Company Pays 4.50% Maturity Date 8/1/20222022-12-310001508655tslx:InterestRateSwapThreeMember2023-01-012023-12-310001508655us-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMembertslx:SecondLienDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMember2023-12-310001508655Equity and Other Investments Financial Services Oxford Square Capital Corp. Common Shares (1,620 shares) Initial Acquisition Date 8/5/20152023-12-310001508655Debt 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%2023-12-310001508655tslx:TwentyTwentyThreeNotesMember2021-12-310001508655srt:MaximumMemberus-gaap:IncomeApproachValuationTechniqueMembertslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputDiscountRateMember2022-12-310001508655Debt Investments, Transportation, Marcura Equities LTD, Inc, First-lien revolving loan ($32,007 par, due 8/2029), Initial Acquisition Date 8/11/2023, Reference Rate and Spread, SOFR + 7.00%, Interest Rate 12.18%2023-01-012023-12-310001508655Equity and Other Investments Business Services WideOrbit, Inc. 1,567,807 Warrants Initial Acquisition Date 7/8/20202022-12-310001508655Debt 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% 2023-01-012023-12-310001508655tslx:InvestmentAdvisoryAgreementMember2023-01-012023-12-310001508655Equity and Other Investments Retail and Consumer Products Copper Bidco, LLC Trust Certificates (996,958 Certificates) Initial Acquisition Date 1/30/20212022-12-310001508655Equity and Other Investments Financial Services Newport Parent Holdings, LP Class A-2 Units (131,569 units) Initial Acquisition Date 12/10/20202022-01-012022-12-310001508655tslx:TwoThousandTwentyFourNotesMemberus-gaap:InterestRateSwapMember2023-01-012023-12-310001508655Equity and Other Investments Education Astra 2L Holdings II LLC Membership Interest (10.17% ownership) Initial Acquisition Date 1/13/20222022-01-012022-12-310001508655Equity and Other Investments Financial Services CLGF Holdco 2, LLC 334,682 Warrants Initial Acquisition Date 11/7/20232023-12-310001508655tslx:EquityAndOtherInvestmentsMember2022-12-310001508655us-gaap:HealthcareSectorMember2023-12-310001508655Debt 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 12.11%2023-01-012023-12-310001508655tslx:NonControlledNonAffiliatedInvestmentsMember2023-12-310001508655Debt 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%2023-12-310001508655Equity and Other Investments Structured Credit Dryden Senior Loan Fund, Series 2018-55A Structured Product ($1,000 par, due 4/2031) Initial Acquisition Date 7/25/2022 Reference Rate and Spread L + 2.85% Interest Rate 5.36%2022-01-012022-12-310001508655Debt 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 12.60%2023-12-310001508655tslx:ControlledAffiliatedInvestmentsMember2023-12-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. Series D Preferred Shares (1,240,740 shares) Initial Acquisition Date 5/11/20212023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:ElysianFincoLtdMember2023-12-310001508655us-gaap:FairValueInputsLevel1Member2022-12-310001508655Equity and Other Investments Hotel, Gaming and Leisure IRGSE Holding Corp. Class C-1 Units (8,800,000 units) Initial Acquisition Date 12/21/20182022-12-310001508655tslx:TiccCapitalCorporationMember2014-12-310001508655tslx:RevolvingCreditsFacilitiesMember2014-12-310001508655Debt Investments Financial Services Jonas Collections and Recovery, Inc. First-lien loan ($19,125 par, due 6/2026) Initial Acquisition Date 6/21/2021 Reference Rate and Spread L + 5.25% Interest Rate 10.40%2022-01-012022-12-310001508655tslx:AutomotiveMember2023-12-310001508655srt:MaximumMembertslx:PharmaceuticalsMember2022-12-310001508655Equity and Other Investments Structured Credit Whitebox CLO I Ltd, Series 2020-2A Structured Product ($1,125 par, due 10/2034) Initial Acquisition Date 7/12/2022 Reference Rate and Spread L + 3.35% Interest Rate 6.13%2022-01-012022-12-310001508655tslx:AdministrationAgreementMember2023-11-012023-11-300001508655Hedge Accounting Swaps2022-01-012022-12-310001508655Debt Investments Automotive Carlstar Group, LLC First-lien loan ($33,575 par, due 7/2027) Initial Acquisition Date 7/8/2022 Reference Rate and Spread SOFR + 6.60% Interest Rate 10.92%2022-01-012022-12-310001508655tslx:InternetServicesMember2023-12-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. 569,991 Warrants Initial Acquisition Date 4/2/20202023-01-012023-12-310001508655us-gaap:FairValueInputsLevel3Membertslx:SecondLienDebtInvestmentsMember2023-01-012023-12-310001508655Debt Investments Hotel, Internet Services Higher Logic, LLC First-lien loan ($55,820 par, due 1/2025) Initial Acquisition Date 6/18/2018 Reference Rate Spread SOFR + 7.25% Interest Rate 11.83%2022-12-310001508655tslx:TwentyTwentyFourNotesMember2019-11-012019-11-300001508655us-gaap:CommonStockMember2020-12-310001508655Equity 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%2023-12-310001508655Interest Rate Swap Company Receives 3.875% Company Pays SOFR + 2.72% Maturity Date 11/1/20242023-01-012023-12-310001508655Debt Investments Hotel, Internet Services Piano Software, Inc First-lien loan ($51,312 par, due 2/2026) Initial Acquisition Date 2/25/2021 Reference Rate Spread SOFR + 7.10% Interest Rate 11.42%2022-01-012022-12-310001508655us-gaap:OverAllotmentOptionMember2023-06-122023-06-120001508655Debt 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 10.02%2022-12-310001508655Equity and Other Investments Structured Credit Ares Loan Funding I Ltd, Series 2021-ALFA, Class E StructuredProduct ($1,000par,due10/2034) Initial Acquisition Date 6/24/2022 Reference Rate and Spread SOFR+6.96% Interest Rate 12.36%2023-01-012023-12-310001508655us-gaap:RevolvingCreditFacilityMembersrt:MinimumMember2023-12-310001508655Equity and Other Investments Structured Credit Wind River CLO Ltd, Series 2014-2A Structured Product ($1,500 par, due 1/2031) Initial Acquisition Date 6/23/2022 Reference Rate and Spread L + 2.90% Interest Rate 5.41%2022-12-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. Series C Preferred Shares (1,915,114 shares) Initial Acquisition Date 10/13/20202023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:KyribaCorpMember2022-12-310001508655tslx:RevolvingCreditsFacilitiesMember2022-12-310001508655tslx:ControlledAffiliatedInvestmentsMember2022-12-310001508655Equity and Other Investments Pharmaceuticals TherapeuticsMD, Inc. 65,250 Warrants Initial Acquisition Date 7/29/20222022-01-012022-12-310001508655Debt Investments Communications Banyan Software Holdings, LLC First-lien loan ($29,739 par, due 10/2026) Initial Acquisition Date 1/7/2023 Reference Rate and Spread SOFR + 7.35% Interest Rate 12.71%2023-12-310001508655Equity and Other Investments Structured Credit Dryden Senior Loan Fund, Series 2018-55A Structured Product ($1,000 par, due 4/2031) Initial Acquisition Date 7/25/2022 Reference Rate and Spread L + 2.85% Interest Rate 5.36%2022-12-310001508655Debt 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%2023-12-310001508655Equity and Other Investments Internet Services Bayshore Intermediate #2, L.P. Co-Invest Common Units (8,837,008 units) Initial Acquisition Date 10/1/20212023-01-012023-12-310001508655Equity 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 L + 6.05% Interest Rate 8.76%2022-01-012022-12-310001508655Interest Rate Swap Company Receives 3.875% Company Pays SOFR + 2.72% Maturity Date 11/1/20242023-12-310001508655Equity 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%2023-01-012023-12-3100015086552023-05-152023-05-150001508655Equity and Other Investments Business Services ReliaQuest, LLC Class A-1 Units (637,713 units) Initial Acquisition Date 11/23/20212023-01-012023-12-310001508655us-gaap:TreasuryStockCommonMember2022-01-012022-12-310001508655tslx:RevolverMembertslx:IRGSEHoldingCorpMember2023-12-310001508655us-gaap:DomesticCountryMember2022-12-310001508655tslx:MezzanineDebtInvestmentsMember2021-12-310001508655Equity and Other Investments Financial Services2023-12-310001508655us-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:SecondLienDebtInvestmentsMembersrt:MinimumMemberus-gaap:MeasurementInputDiscountRateMember2022-12-310001508655Debt Investments Healthcare Raptor US Buyer II Corp. First-lien loan ($15,569 par,due3/2029) 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 12/8/20202023-01-012023-12-310001508655Debt Investments Business services ForeScout Technologies, Inc. First-lien loan ($6,502 par, due 8/2026) Initial Acquisition Date 8/17/2020 Reference Rate and Spread L + 9.50% Interest Rate 14.23% (incl. 9.50% PIK)2022-12-310001508655srt:MaximumMembercountry:FI2022-12-310001508655Debt Investments Chemicals2023-12-310001508655Debt 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%2023-01-012023-12-310001508655tslx:BlackScholesModelMembertslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Member2022-12-310001508655Debt 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%2023-12-310001508655us-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:SecondLienDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMembersrt:WeightedAverageMember2022-12-310001508655Interest Rate Swap Company Receives 2.50% Company Pays L + 1.91% Maturity Date 8/1/20262022-12-310001508655Debt 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%2023-01-012023-12-310001508655Debt Investments Other Omnigo Software, LLC First-lien loan ($40,353 par, due 3/2026) Initial Acquisition Date 12/3/2021 Reference Rate Spread SOFR + 6.60% Interest Rate 10.92%2022-01-012022-12-310001508655Equity and Other Investments Business Services Mitnick TA Aggregator, L.P. Membership Interest (0.43% ownership) Initial Acquisition Date 5/2/20222023-12-310001508655Equity 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 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 L + 3.33% Interest Rate 6.04%2022-12-310001508655tslx:HotelGamingAndLeisureMember2022-12-310001508655tslx:LeverageWaiverMembertslx:InvestmentAdvisoryAgreementMember2021-01-012021-12-310001508655Debt 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)2023-01-012023-12-3100015086552023-04-012023-12-310001508655Equity 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 L + 6.60% Interest Rate 9.11%2022-12-310001508655tslx:MezzanineDebtInvestmentsMember2023-01-012023-12-310001508655us-gaap:RetainedEarningsMember2022-12-310001508655Controlled Affiliated Investments2022-01-012022-12-310001508655Equity 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:PingIdentityCorporationMembertslx:RevolverMember2022-12-310001508655Debt 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 7.74%2022-01-012022-12-310001508655Debt Investments Hotel, Internet Services2022-12-310001508655Equity and Other Investments Business Services ReliaQuest, LLC Class A-1 Units (567,683 units) Initial Acquisition Date 11/23/20212022-01-012022-12-310001508655Equity and Other Investments Structured Credit Ares 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 L + 6.70% Interest Rate 9.21%2022-12-310001508655tslx:MidwestMember2023-12-310001508655Equity 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 8.51%2023-01-012023-12-310001508655Interest Rate Swap Company Receives L+2.28% Maturity Date 11/1/20242022-12-3100015086552021-01-012021-03-310001508655tslx:InterestRateSwapSixMember2022-01-012022-12-310001508655us-gaap:OverAllotmentOptionMember2021-03-240001508655tslx:ArtisanBidcoIncMembertslx:RevolverMember2023-12-310001508655Debt 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 PIK%2023-01-012023-12-310001508655tslx:TwoThousandTwentyTwoConvertibleNotesMember2022-08-010001508655Debt Investments Mach Natural Resource 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%2023-01-012023-12-3100015086552015-08-042015-08-040001508655Debt Investments Hotel, Internet Services Lithium Technologies, LLC First-lien loan ($54,700 par, due 1/2024) Initial Acquisition Date 10/3/2017 Reference Rate Spread SOFR + 8.00% Interest Rate 12.06%2022-01-012022-12-310001508655Equity and Other Investments Education2023-12-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. Series D Preferred Shares (1,598,874 shares) Initial Acquisition Date 4/8/20212022-12-310001508655Debt Investments Business services Mitnick Corporate Purchaser, Inc. First-lien loan ($333 par, due 5/2029) Initial Acquisition Date 5/2/2022 Reference Rate and Spread SOFR + 4.85% Interest Rate 8.94%2022-01-012022-12-310001508655Equity 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 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%2023-01-012023-12-310001508655us-gaap:TreasuryStockCommonMember2021-12-310001508655tslx:TwoThousandTwentyFourNotesMember2020-01-012020-12-310001508655us-gaap:UnfundedLoanCommitmentMember2023-12-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. 569,991 Warrants Initial Acquisition Date 4/2/20202022-12-310001508655Equity and Other Investments Structured Credit Crown Point CLO Ltd, Series 2021-10A Structured Product ($1,000 par, due 7/2034) Initial Acquisition Date 6/14/2022 Reference Rate and Spread L + 6.85% Interest Rate 9.56%2022-01-012022-12-310001508655tslx:NonControlledAffiliatedInvestmentsMember2022-01-012022-12-310001508655tslx:RevolverMembertslx:BayshoreIntermediate2LPMember2022-12-310001508655Debt 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%2023-01-012023-12-310001508655Equity and Other Investments Oil, Gas and Consumable Fuels Murchison Oil and Gas, LLC 13,355 Preferred Units Initial Acquisition Date 6/30/20222022-01-012022-12-310001508655tslx:TwentyTwentyFourNotesMember2023-12-310001508655Debt Investments Business services Information Clearinghouse, LLC and MS Market Service, LLC First-lien loan ($17,820 par, due 12/2026) Initial Acquisition Date 12/20/2021 Reference Rate and Spread SOFR + 6.65% Interest Rate 11.16%2022-01-012022-12-310001508655Equity and Other Investments Education RMCF IV CIV XXXV, LP. Partnership Interest (11.94% ownership) Initial Acquisition Date 6/8/20212022-01-012022-12-310001508655us-gaap:RevolvingCreditFacilityMembersrt:MaximumMember2023-01-012023-12-310001508655Controlled Affiliated Investments IRGSE Holding Corp.2022-01-012022-12-310001508655Debt 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 Internet Services Bayshore Intermediate #2, L.P. Common Units (12,330,709 units) Initial Acquisition Date 10/1/20212022-12-310001508655tslx:BaseDividendMember2022-05-032022-05-030001508655Equity 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:TwoThousandTwentyThreeNotesMember2018-01-012018-01-310001508655Equity and Other Investments Business Services ReliaQuest, LLC Class A-3 Units (16,957 units) Initial Acquisition Date 11/10/20232023-01-012023-12-310001508655tslx:RevolverMembertslx:GalileoParentincMember2023-12-310001508655Debt Investments Business services Dye & Durham Corp. First-lien loan (CAD 34,220 par, due 12/2027) Initial Acquisition Date 12/3/2021 Reference Rate and Spread C + 5.75% Interest Rate 10.69%2022-12-310001508655tslx:DelayedDrawMembertslx:AlphaMidcoIncMember2022-12-310001508655tslx:TwoThousandTwentyTwoConvertibleNotesMember2022-01-260001508655Debt Investments Education Astra Acquisition Corp. Second-lien loan ($43,479 par, due 10/2029) Initial Acquisition Date 10/25/2021 Reference Rate and Spread L + 8.88% Interest Rate 13.26%2022-12-310001508655Debt Investments Healthcare Caris Life Sciences, Inc. Convertible note ($2,602 par, due 9/2023) Initial Acquisition Date 9/21/2018 Reference Rate and Spread 8.00% Interest Rate 8.00%2022-01-012022-12-310001508655Equity and Other Investments Structured Credit Gulf Stream Meridian, Series 2021-6A Structured Product ($2,000 par, due 1/2037) Initial Acquisition Date 9/12/2022 Reference Rate and Spread L + 6.36% Interest Rate 8.87%2022-01-012022-12-310001508655tslx:EquityAndOtherInvestmentsMember2023-01-012023-12-310001508655tslx:TwentyTwentyNineNotesMember2024-01-082024-01-080001508655Debt 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%2023-12-310001508655Equity and Other Investments Structured Credit Whitebox CLO I Ltd, Series 2020-2A Structured Product ($1,125 par, due 10/2034) Initial Acquisition Date 7/12/2022 Reference Rate and Spread L + 3.35% Interest Rate 6.13%2022-12-310001508655Debt 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%2023-12-310001508655us-gaap:FairValueInputsLevel3Member2022-01-012022-12-310001508655Equity and Other Investments Business Services ReliaQuest, LLC Class A-1 Units (637,713 units) Initial Acquisition Date 11/23/20212023-12-310001508655Debt 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%2023-01-012023-12-310001508655Debt Investments Oil, Gas and Consumable Fuels TRP Assets, LLC First-lien loan ($57,818 par, due 12/2025) Initial Acquisition Date 12/3/2021 Reference Rate Spread SOFR + 7.76% Interest Rate 12.34%2022-12-310001508655tslx:ReliaQuestHoldingsLLCMembertslx:DelayedDrawRevolverPreferredEquityMember2022-12-310001508655tslx:DelayedDrawMembertslx:ArrowbuyerIncMember2023-12-310001508655Equity 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 Communications IntelePeer Holdings, Inc. Series D Preferred Shares (1,598,874 shares) Initial Acquisition Date 4/8/20212023-12-310001508655us-gaap:OverAllotmentOptionMember2021-03-242021-03-240001508655Debt 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%2023-12-310001508655Debt Investments Retail and Consumer Products Project P Intermediate 2, LLC ABL FILO term loan ($73,125 par, due 5/2026) Initial Acquisition Date 11/8/2021 Reference Rate and Spread L + 8.00% Interest Rate 12.41%2022-01-012022-12-310001508655tslx:RevolvingCreditsFacilitiesMember2021-12-310001508655Debt 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%2023-12-310001508655Equity and Other Investments Structured Credit Wind River CLO Ltd, Series 2018-3A Structured Product ($2,000 par, due 1/2031) Initial Acquisition Date 12/12/2022 Reference Rate and Spread L + 5.65% Interest Rate 6.46%2022-01-012022-12-310001508655Equity and Other Investments Structured Credit GoldenTree CLO Ltd, Series 2020-7A Structured Product ($1,000 par, due 4/2034) Initial Acquisition Date 6/17/2022 Reference Rate and Spread L + 6.50% Interest Rate 9.21%2022-01-012022-12-310001508655Debt 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 PIK%2023-12-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. 280,000 Series C Warrants Initial Acquisition Date 2/28/20202023-01-012023-12-310001508655tslx:AmericanAchievementCorpMembertslx:RevolverMember2022-12-310001508655tslx:RevolvingCreditFacilityMaturityOnJuneTwelveTwoThousandAndTwentyEightMember2023-01-012023-12-310001508655tslx:EquityAndOtherInvestmentsMembertslx:AssetValuationWaterfallMemberus-gaap:FairValueInputsLevel3Member2022-12-310001508655Debt Investments Business services Dye & Durham Corp. First-lien revolving loan (CAD 1,448 par, due 12/2026) Initial Acquisition Date 12/3/2021 Reference Rate and Spread P + 6.75% Interest Rate 11.2%2022-01-012022-12-310001508655Debt 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 10.39%2023-01-012023-12-310001508655Debt 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%2023-01-012023-12-310001508655Equity and Other Investments Internet Services Lucidworks, Inc. Series F Preferred Shares (199,054 shares) Initial Acquisition Date 8/2/20192022-12-310001508655Interest Rate Swap Company Receives 4.50% Company Pays L + 2.37% Maturity Date 8/1/20222022-01-012022-12-310001508655Debt 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%2023-12-310001508655us-gaap:FairValueInputsLevel3Member2023-01-012023-12-310001508655Equity and Other Investments Internet Services SMA Technologies Holdings, LLC Class B Units (923,250 shares) Initial Acquisition Date 11/21/20222022-01-012022-12-310001508655tslx:TwoThousandTwentyThreeTwentyFourTwentySixAndTwentyEightNotesMember2023-01-012023-12-310001508655tslx:DelayedDrawMembertslx:LaramieEnergyLLCMember2023-12-310001508655Debt 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%2023-01-012023-12-310001508655us-gaap:CommonStockMember2022-01-012022-12-310001508655tslx:BlueSnapIncMembertslx:RevolverMember2022-12-310001508655tslx:BaseDividendMember2022-08-020001508655Equity 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:MezzanineDebtInvestmentsMember2023-12-310001508655tslx:FirstLienDebtInvestmentsMember2023-12-310001508655Debt Investments Business services TIBCO Software Inc. First-lien loan ($12,000 par, due 3/2029) Initial Acquisition Date 9/20/2022 Reference Rate and Spread SOFR + 4.60% Interest Rate 9.19%2022-12-310001508655Equity and Other Investments Retail and Consumer Products American Achievement, Corp. Class A Units (687 units) Initial Acquisition Date 3/16/20212023-01-012023-12-310001508655tslx:SpecialDividendMember2021-11-022021-11-020001508655Equity and Other Investments Structured Credit CIFC CLO Ltd, Series 2018-3A Structured Product ($1,000 par, due 7/2031) Initial Acquisition Date 6/16/2022 Reference Rate and Spread L + 5.50% Interest Rate 8.24%2022-01-012022-12-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. 633,376 Warrants Initial Acquisition Date 9/21/20182023-01-012023-12-310001508655country:LU2023-12-310001508655Equity 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 L + 2.85% Interest Rate 5.36%2022-12-310001508655tslx:ControlledAffiliatedInvestmentsMember2021-01-012021-12-310001508655Equity 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 L + 5.75% Interest Rate 8.26%2022-01-012022-12-310001508655Equity 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%2023-12-310001508655tslx:RevolvingCreditsFacilitiesMember2016-12-310001508655Equity and Other Investments Retail and Consumer Products Neuintel, LLC Class A Units (1,176,494 units) Initial Acquisition Date 12/21/20212022-12-310001508655us-gaap:RevolvingCreditFacilityMember2023-12-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. 106,592 Warrants Initial Acquisition Date 4/8/20212022-12-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. 280,000 Series C Warrants Initial Acquisition Date 2/28/20202023-12-310001508655tslx:ConvertibleSeniorNotesDueTwentyNineteenMember2018-12-310001508655Debt Investments Healthcare Caris Life Sciences, Inc. First-lien loan ($5,000 par, due 9/2023) Initial Acquisition Date 9/21/2018 Reference Rate and Spread 11.30% Interest Rate 11.30%2022-01-012022-12-3100015086552023-12-310001508655Interest Rate Swap Company Receives 3.875% Company SOFR + 2.51% Maturity Date 11/1/20242023-12-310001508655Debt 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 + 6.50% Interest Rate 9.77%2022-01-012022-12-310001508655tslx:DelayedDrawMembertslx:AsgIiLlcMember2023-12-310001508655Equity 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%2023-01-012023-12-310001508655us-gaap:TreasuryStockCommonMember2020-12-310001508655tslx:MezzanineDebtInvestmentsMember2022-12-310001508655Controlled Affiliated Investments Mississippi Resources, LLC2022-01-012022-12-310001508655tslx:TwentyTwentySixNotesMember2023-01-012023-12-310001508655Equity and Other Investments Business Services Warrior TopCo LP Class A Units (423,728 units) Initial Acquisition Date 7/7/20232023-12-310001508655tslx:GeneralRiskFactorsMember2023-01-012023-12-310001508655tslx:FirstLienDebtInvestmentsMember2022-12-310001508655tslx:DelayedDrawMembertslx:Project44IncMember2022-12-310001508655Equity and Other Investments Structured Credit Wind River CLO Ltd, Series 2017-1A Structured Product ($3,000 par, due 4/2036) Initial Acquisition Date 7/14/2022 Reference Rate and Spread L + 3.72% Interest Rate 6.46%2022-12-310001508655tslx:ChemicalsMember2023-12-310001508655Equity and Other Investments Pharmaceuticals TherapeuticsMD, Inc. 14,256 Warrants Initial Acquisition Date 8/5/20202023-12-310001508655Debt Investments Education EMS Linq, Inc. First-lien loan ($56,216 par, due 12/2027) Initial Acquisition Date 12/22/2021 Reference Rate and Spread L + 6.25% Interest Rate 10.63%2022-12-310001508655tslx:TwoThousandTwentyEightNotesMember2023-01-012023-12-310001508655Debt 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%2023-01-012023-12-310001508655Debt 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 11.32%2022-01-012022-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:RapidDataGmbhUnternehmensberatungMember2023-12-310001508655Equity and Other Investments Structured Credit CIFC CLO Ltd, Series 2021-4A Structured Product ($1,000 par, due 7/2033) Initial Acquisition Date 7/14/2022 Reference Rate and Spread L + 6.00% Interest Rate 8.51%2022-01-012022-12-310001508655Equity and Other Investments Financial Services AF Eagle Parent, L.P. Partnership (121,329 units) Initial Acquisition Date 11/27/20232023-01-012023-12-310001508655tslx:SupplementalDividendMember2021-02-172021-02-170001508655Equity and Other Investments Healthcare2022-12-310001508655Equity and Other Investments Structured Credit Eaton CLO Ltd, Series 2020-1A Structured Product ($1,000 par, due 10/2034) Initial Acquisition Date 8/11/2022 Reference Rate and Spread L + 6.25% Interest Rate 8.76%2022-01-012022-12-310001508655Equity and Other Investments Financial Services Passport Labs, Inc. 17,534 Warrants Initial Acquisition Date 4/28/20212022-12-310001508655Equity 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%2023-12-310001508655Equity 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%2023-12-310001508655Equity and Other Investments Internet Services Piano Software, Inc. Series C-1 Preferred Shares (418,527 shares) Initial Acquisition Date 12/22/20212022-01-012022-12-310001508655Interest Rate Swap Company Receives 3.875% Maturity Date 11/1/20242022-12-310001508655Debt Investments Human Resource Support Services2022-12-310001508655Debt Investments Retail and Consumer Products American Achievement, Corp. First-lien loan ($1,363 par, due 9/2026) Initial Acquisition Date 6/10/2021 Reference Rate and Spread L + 14.00 % Interest Rate 18.13% (incl. 17.63% PIK)2022-01-012022-12-310001508655Equity and Other Investments Internet Services Piano Software, Inc. Series C-1 Preferred Shares (418,527 shares) Initial Acquisition Date 12/22/20212022-12-310001508655tslx:BaseDividendMember2023-08-030001508655Debt 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%2023-12-310001508655Equity 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%2023-12-310001508655country:AU2023-12-310001508655Debt 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 L + 8.50 % Interest Rate 13.23%2022-12-310001508655us-gaap:FairValueInputsLevel2Member2022-12-3100015086552020-01-012020-12-310001508655Equity 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%2023-01-012023-12-310001508655tslx:BlueSnapIncMembertslx:RevolverMember2023-12-310001508655Debt Investments Communications IntelePeer Holdings, Inc. Convertible note ($4,382 par, due 5/2028) Initial Acquisition Date 5/12/2021 Reference Rate and Spread 6.50% Interest Rate 6.50% PIK2022-01-012022-12-310001508655tslx:DelayedDrawMembertslx:GTreasurySSLLCMember2022-12-310001508655Debt 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%2023-12-310001508655Equity and Other Investments Financial Services Passport Labs, Inc. 17,534 Warrants Initial Acquisition Date 4/28/20212022-01-012022-12-310001508655tslx:ConvertibleSeniorNotesDueTwentyTwentyTwoMember2017-12-310001508655tslx:DelayedDrawMembertslx:AxonifyIncMember2023-12-310001508655Debt Investments Education2023-12-310001508655Equity and Other Investments Retail and Consumer Products Copper Bidco, LLC Trust Certificates (132,928 Certificates) Initial Acquisition Date 12/7/20202022-01-012022-12-310001508655Debt Investments Human Resource Support Services PageUp People, Ltd. First-lien loan (GBP 3,766 par, due 12/2025) Initial Acquisition Date 10/28/2021 Reference Rate and Spread S + 5.62% Interest Rate 8.55%2022-12-310001508655Equity and Other Investments Communications Celtra Technologies, Inc. Class A Units (1,250,000 units) Initial Acquisition Date 11/19/20212022-12-310001508655tslx:CordanceOperationsLlcMembertslx:RevolverMember2023-12-310001508655Debt Investments Communications IntelePeer Holdings, Inc. Convertible note ($4,382 par, due 5/2028) Initial Acquisition Date 5/12/2021 Reference Rate and Spread 6.50% Interest Rate 6.50% PIK2022-12-310001508655us-gaap:IncomeApproachValuationTechniqueMembertslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputDiscountRateMember2022-12-310001508655Debt Investments Healthcare Caris Life Sciences, Inc. First-lien loan ($3,750 par, due 4/2025) Initial Acquisition Date 4/2/2020 Reference Rate and Spread 11.30% Interest Rate 11.30%2022-12-310001508655tslx:ControlledAffiliatedInvestmentsMember2022-01-012022-12-310001508655Debt Investments Healthcare BCTO Ace Purchaser, Inc. First-lien loan ($63,565 par, due 11/2026) Initial Acquisition Date 11/23/2020 Reference Rate and Spread SOFR + 7.70% Interest Rate 12.10 %2022-12-310001508655tslx:RevolverMembertslx:DyeDurhamCorpMember2023-12-310001508655srt:MaximumMemberus-gaap:IncomeApproachValuationTechniqueMembertslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputDiscountRateMember2023-12-310001508655Debt Investments Human Resource Support Services PageUp People, Ltd. First-lien loan (AUD 14,520 par, due 12/2025) Initial Acquisition Date 1/11/2018 Reference Rate and Spread B + 5.50% Interest Rate 9.28%2022-12-310001508655Debt Investments Financial Services Kyriba Corp. First-lien loan (EUR 9,924 par, due 4/2025) Initial Acquisition Date 4/9/2019 Reference Rate and Spread E + 9.00% Interest Rate 11.20% (incl. 9.00% PIK)2022-01-012022-12-310001508655tslx:AdviserMemberus-gaap:GeneralAndAdministrativeExpenseMembertslx:AdministrationAgreementMember2021-01-012021-12-310001508655Debt Investments Transportation Project44, Inc. First-lien loan ($35,139 par, due 11/2027) Initial Acquisition Date 11/12/2021 Reference Rate and Spread L + 6.25% Interest Rate 11.41%2022-12-310001508655tslx:BaseDividendMember2021-05-040001508655tslx:TransportationMember2023-12-310001508655Debt 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%2023-01-012023-12-310001508655tslx:EquityAndOtherInvestmentsMember2023-12-310001508655Equity 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%2023-12-3100015086552018-01-012018-12-310001508655Debt 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%2023-12-310001508655Debt Investments Financial Services G Treasury SS, LLC First-lien loan ($65,859 par, due 4/2024) Initial Acquisition Date 4/9/2018 Reference Rate and Spread SOFR + 8.40% Interest Rate 12.94%2022-12-310001508655tslx:TwoThousandTwentyThreeTwentyFourTwentySixAndTwentyEightNotesMember2021-01-012021-12-310001508655Equity 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%2023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:HornetsecurityHoldingGmbhMember2022-12-310001508655Equity and Other Investments Structured Credit Jefferson Mill CLO Ltd, Series 2015-1A Structured Product ($1,000 par, due 10/2031) Initial Acquisition Date 5/23/2022 Reference Rate and Spread L + 3.55% Interest Rate 6.26%2022-01-012022-12-310001508655Equity and Other Investments Communications Celtra Technologies, Inc. Class A Units (1,250,000 units) Initial Acquisition Date 11/19/20212022-01-012022-12-310001508655tslx:TwentyTwentyEightNotesMember2023-01-012023-12-310001508655tslx:SupplementalDividendMember2021-11-020001508655Equity 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%2023-12-310001508655Debt 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% PIK2023-01-012023-12-310001508655tslx:RevolverMembertslx:AvalaraIncMember2023-12-310001508655Debt 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%2023-12-310001508655us-gaap:NondesignatedMemberus-gaap:InterestRateSwapMember2022-01-012022-12-310001508655Debt Investments Business services Alpha Midco, Inc. First-lien loan ($68,720 par, due 8/2025) Initial Acquisition Date 8/15/2019 Reference Rate and Spread SOFR + 7.63% Interest Rate 12.21%2022-01-012022-12-310001508655Debt Investments Financial Services TradingScreen, Inc. First-lien loan ($44,663 par, due 4/2027) Initial Acquisition Date 4/30/2021 Reference Rate and Spread L + 6.25% Interest Rate 10.66%2022-01-012022-12-310001508655Debt 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%2023-01-012023-12-310001508655Equity 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 L + 2.70% Interest Rate 5.44%2022-01-012022-12-310001508655tslx:BaseDividendMember2023-05-082023-05-080001508655tslx:TwentyTwentyFourNotesMember2020-12-310001508655Equity and Other Investments Internet Services SMA Technologies Holdings, LLC Class B Units (923,250 shares) Initial Acquisition Date 11/21/20222023-12-310001508655Debt Investments Oil, Gas and Consumable Fuels2023-12-310001508655us-gaap:FinancialServicesSectorMember2022-12-310001508655us-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:SecondLienDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMembersrt:WeightedAverageMember2023-12-310001508655tslx:InterestRateSwapEightMember2022-01-012022-12-310001508655Equity and Other Investments Communications2022-12-310001508655tslx:AssetValuationWaterfallMembertslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Member2022-12-310001508655Equity 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 11.93%2023-12-310001508655Equity 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 Services2023-12-310001508655Debt 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%2023-12-310001508655Equity and Other Investments Business Services2023-12-310001508655tslx:SecondLienDebtInvestmentsMember2022-12-310001508655Equity and Other Investments Marketing Services Validity, Inc. Series A Preferred Shares (3,840,000 shares) Initial Acquisition Date 5/31/20182023-01-012023-12-310001508655tslx:BaseDividendMember2021-08-030001508655tslx:KangarooBidcoASMembertslx:DelayedDrawMember2023-12-310001508655tslx:MezzanineDebtInvestmentsMember2023-12-310001508655Equity and Other Investments Human Resource Support Services ClearCompany, LLC Series A Preferred Units (1,429,228 units) Initial Acquisition Date 8/24/20182022-12-310001508655Debt Investments Financial Services PrimeRevenue, Inc. First-lien loan ($22,507 par, due 12/2023) Initial Acquisition Date 12/31/2018 Reference Rate and Spread L + 7.00% Interest Rate 11.38%2022-12-310001508655Debt Investments Mach Resource, First-lien loan ($5,000 par, due 12/2026) Initial Acquisition Date 12/28/2023 Reference Rate and Spread SOFR + 6.50% Interest Rate 12.00%2023-01-012023-12-310001508655us-gaap:IncomeApproachValuationTechniqueMembertslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputDiscountRateMembersrt:WeightedAverageMember2023-12-310001508655Debt Investments Human Resource Support Services Axonify, Inc First-lien loan ($47,122 par, due 5/2026) Initial Acquisition Date 5/5/2021 Reference Rate and Spread SOFR + 7.65% Interest Rate 11.83%2022-01-012022-12-310001508655us-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:SecondLienDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMember2023-12-310001508655tslx:TwentyTwentyFourNotesMember2023-01-012023-12-310001508655Debt 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%2023-01-012023-12-310001508655Debt 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 11.32%2022-12-310001508655Equity and Other Investments Structured Credit Crown Point CLO Ltd, Series 2021-10A Structured Product ($1,000 par, due 7/2034) Initial Acquisition Date 6/14/2022 Reference Rate and Spread L + 6.85% Interest Rate 9.56%2022-12-310001508655Debt Investments Financial Services Ibis US Blocker Co. First-lien loan ($13,957 par, due 5/2028) Initial Acquisition Date 5/28/2021 Reference Rate and Spread L + 8.25% Interest Rate 12.98% PIK2022-12-310001508655Equity and Other Investments Business Services ReliaQuest, LLC Class A-1 Units (567,683 units) Initial Acquisition Date 11/23/20212022-12-310001508655Debt 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%2023-12-310001508655Equity and Other Investments Business Services Dye & Durham, Ltd. Common Shares (126,968 shares) Initial Acquisition Date 12/3/20212023-12-310001508655Equity 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 11.02%2023-12-310001508655tslx:DelayedDrawMembertslx:LeantaasHoldingsIncMember2023-12-310001508655Debt 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 + 6.50% Interest Rate 9.77%2022-12-310001508655Debt 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%2023-12-310001508655tslx:DelayedDrawAndMembershipInterestMembertslx:TRPAssetsLLCMember2023-12-310001508655Equity and Other Investments Business Services ReliaQuest, LLC Class A-2 Units (2,989 units) Initial Acquisition Date 6/21/20222023-12-310001508655tslx:RevolvingCreditFacilityMaturityOnJanuary312025Member2023-12-310001508655Debt 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 Marketing Services Validity, Inc. Series A Preferred Shares (3,840,000 shares) Initial Acquisition Date 5/31/20182022-01-012022-12-310001508655Equity and Other Investments Structured Credit Benefit Street Partners CLO Ltd, Series 2015-8A Structured Product ($1,425 par, due 1/2031) Initial Acquisition Date 9/13/2022 Reference Rate and Spread L + 2.75% Interest Rate 5.46%2022-01-012022-12-310001508655tslx:RevolverMembertslx:BayshoreIntermediate2LPMember2023-12-310001508655tslx:InterestRateSwapThreeMember2022-01-012022-12-310001508655Debt 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%2023-01-012023-12-3100015086552017-12-310001508655tslx:TwoThousandTwentySixNotesMember2022-01-012022-12-310001508655Debt 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%2023-12-310001508655us-gaap:TreasuryStockCommonMember2022-12-310001508655Equity and Other Investments Structured Credit2023-12-310001508655tslx:RevolvingCreditFacilityMaturityOnFebruary42026Member2023-12-310001508655Debt 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%2023-01-012023-12-3100015086552017-01-012017-12-310001508655Debt 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 L + 14.10% Interest Rate 18.94% (PIK)2023-12-310001508655Debt Investments, Manufacturing,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%2023-12-310001508655tslx:InterestRateSwapOneMember2022-01-012022-12-310001508655Equity and Other Investments Internet Services Lucidworks, Inc. Series F Preferred Shares (199,054 shares) Initial Acquisition Date 8/2/20192022-01-012022-12-310001508655Debt 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%2023-01-012023-12-3100015086552021-04-012021-12-310001508655Debt 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%2023-01-012023-12-310001508655Debt 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 11.84%2022-01-012022-12-310001508655Debt Investments Business services WideOrbit, Inc. First-lien loan ($35,548 par, due 7/2025) Initial Acquisition Date 7/8/2020 Reference Rate and Spread L + 8.50% Interest Rate 12.88%2022-01-012022-12-310001508655tslx:TwentyTwentySixNotesMember2023-12-310001508655Equity 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%2023-12-310001508655Interest Rate Swap Company Receives 3.875% Company Pays L + 2.25% Maturity Date 11/1/20242022-01-012022-12-310001508655tslx:AutomotiveMember2022-12-310001508655Equity and Other Investments Structured Credit Gulf Stream Meridian, Series 2021-4A Structured Product ($1,015 par, due 7/2034) Initial Acquisition Date 6/3/2022 Reference Rate and Spread L + 6.35% Interest Rate 8.86%2022-12-310001508655tslx:RevolvingCreditFacilityMaturityOnJanuary312025Member2023-01-012023-12-310001508655us-gaap:AssetPledgedAsCollateralMember2023-12-310001508655Debt 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 12.02%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 10.70%2023-01-012023-12-310001508655Equity and Other Investments Business Services WideOrbit, Inc. 1,567,807 Warrants Initial Acquisition Date 7/8/20202022-01-012022-12-310001508655Equity and Other Investments Oil, Gas and Consumable Fuels2023-12-310001508655tslx:OtherMember2023-12-310001508655tslx:BaseDividendMember2022-11-010001508655Equity and Other Investments Internet Services Bayshore Intermediate #2, L.P. Co-Invest 2 Common Units (3,493,701 units) Initial Acquisition Date 10/1/20212023-01-012023-12-310001508655tslx:BaseDividendMember2022-08-022022-08-020001508655tslx:InvestmentAdvisoryAgreementMember2021-01-012021-12-310001508655Debt 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 L + 8.50 % Interest Rate 13.23%2022-01-012022-12-310001508655Equity and Other Investments Business Services2022-12-310001508655Debt 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%2023-12-310001508655Debt Investments Hotel, Manufacturing Avalara, Inc First-lien loan ($38,636 par, due 10/2028) Initial Acquisition Date 10/19/2022 Reference Rate Spread SOFR + 7.25% Interest Rate 11.83%2022-01-012022-12-310001508655us-gaap:RetainedEarningsMember2020-12-310001508655Debt Investments Education Astra Acquisition Corp. Second-lien loan ($43,479 par, due 10/2029) Initial Acquisition Date 10/25/2021 Reference Rate and Spread L + 8.88% Interest Rate 13.26%2022-01-012022-12-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. 569,991 Warrants Initial Acquisition Date 4/2/20202023-12-310001508655us-gaap:RevolvingCreditFacilityMembersrt:MaximumMember2023-12-310001508655us-gaap:AssetPledgedAsCollateralMember2022-12-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. 569,991 Warrants Initial Acquisition Date 4/2/20202022-01-012022-12-310001508655Debt Investments Financial Services BTRS Holdings, Inc. First-lien loan ($1,205 par, due 12/2028) Initial Acquisition Date 12/16/2022 Reference Rate and Spread SOFR + 7.25% Interest Rate 12.63%2023-01-012023-12-310001508655Controlled Affiliated Investments IRGSE Holding Corp.2023-12-310001508655Debt Investments Business services TIBCO Software Inc. First-lien note ($13,000 par, due 3/2029) Initial Acquisition Date 9/20/2022 Reference Rate and Spread 6.50% Interest Rate 6.5%2022-12-310001508655Debt 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%2023-01-012023-12-310001508655us-gaap:AdditionalPaidInCapitalMember2022-12-310001508655Equity and Other Investments Communications IntelePeer Holdings, Inc. 280,000 Warrants Initial Acquisition Date 2/28/20202022-01-012022-12-310001508655Interest Rate Swap Company Receives L Company Pays 4.50% Maturity Date 8/1/20222022-12-310001508655Debt 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%2023-01-012023-12-310001508655us-gaap:InterestRateSwapMember2022-12-310001508655Debt 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%2023-12-310001508655Debt 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%2023-01-012023-12-310001508655country:GB2023-12-310001508655Debt 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%2023-12-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. Series C Preferred Shares (362,319 shares) Initial Acquisition Date 10/13/20202022-12-310001508655Equity 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%2023-12-3100015086552023-01-012023-03-310001508655us-gaap:AdditionalPaidInCapitalMember2022-01-012022-12-310001508655Debt Investments Human Resource Support Services Axonify, Inc First-lien loan ($44,806 par, due 11/2028) Initial Acquisition Date 11/7/2022 Reference Rate and Spread SOFR + 6.63% Interest Rate 10.81%2022-01-012022-12-310001508655Debt Investments Hotel, Internet Services Workwell Bayshore Intermediate #2, L. First-lien loan ($32,194 par, due 10/2028) Initial Acquisition Date 10/1/2021 Reference Rate Spread L + 7.75% Interest Rate 12.04% PIK2022-01-012022-12-310001508655Equity 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%2023-01-012023-12-310001508655tslx:RevolvingCreditFacilityMaturityOnJuneTwelveTwoThousandAndTwentyEightMember2023-12-310001508655country:FI2023-12-310001508655Debt Investments Business services Mitnick Corporate Purchaser, Inc. First-lien loan ($333 par, due 5/2029) Initial Acquisition Date 5/2/2022 Reference Rate and Spread SOFR + 4.85% Interest Rate 8.94%2022-12-310001508655Equity and Other Investments Structured Credit Ares CLO Ltd, Series 2021-59A Structured Product ($1,000 par, due 4/2034) Initial Acquisition Date 6/23/2022 Reference Rate and Spread L + 6.25% Interest Rate 9.03%2022-12-310001508655Debt 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 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:DelayedDrawMembertslx:ExtraHopNetworksIncMember2022-12-3100015086552018-12-310001508655Debt 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%2023-01-012023-12-310001508655tslx:EMSLinqIncMembertslx:RevolverMember2022-12-310001508655Interest Rate Swap Company Receives L Company Pays 4.50% Maturity Date 8/1/20222022-01-012022-12-3100015086552022-03-310001508655Debt 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%2023-01-012023-12-310001508655us-gaap:HealthcareSectorMember2022-12-310001508655Debt 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% 2023-12-310001508655Interest Rate Swap Company Pays L + 2.46% Maturity Date 11/1/20242022-12-310001508655Equity and Other Investments Communications Celtra Technologies, Inc. Class A Units (1,250,000 units) Initial Acquisition Date 11/19/20212023-12-310001508655tslx:BaseDividendMember2022-05-030001508655Equity 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 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%2023-12-310001508655us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InterestRateSwapMember2023-01-012023-12-310001508655Debt 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 L + 14.10% Interest Rate 18.94% (PIK)2023-01-012023-12-310001508655us-gaap:InvestmentAffiliatedIssuerControlledMember2022-01-012022-12-310001508655Debt 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:IncomeApproachValuationTechniqueMembertslx:MezzanineDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputDiscountRateMembersrt:WeightedAverageMember2023-12-310001508655country:CA2023-12-310001508655Interest Rate Swap3 Company Pays 4.50% Maturity Date 8/1/20222022-12-310001508655us-gaap:RetainedEarningsMember2021-12-310001508655Equity and Other Investments Human Resource Support Services Axonify, Inc. Class A-1 Units (3,780,000 units) Initial Acquisition Date 5/5/20212023-01-012023-12-310001508655tslx:EquityAndOtherInvestmentsMember2023-01-012023-12-310001508655Debt 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%2023-01-012023-12-310001508655us-gaap:UnfundedLoanCommitmentMember2022-12-310001508655Equity and Other Investments Business Services Newark FP Co-Invest, L.P. Partnership (2,527,719 units) Initial Acquisition Date 11/8/20232023-01-012023-12-310001508655tslx:AssetValuationWaterfallMembertslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Member2023-12-310001508655Debt 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%2023-12-3100015086552015-12-310001508655Debt 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%2023-01-012023-12-310001508655Equity 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 8.56%2023-01-012023-12-310001508655Equity and Other Investments Healthcare2023-12-310001508655Debt Investments Retail and Consumer Products2022-12-310001508655tslx: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 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%2023-01-012023-12-310001508655us-gaap:RetainedEarningsMember2021-01-012021-12-310001508655Equity 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 L + 2.70% Interest Rate 5.44%2022-12-310001508655Equity and Other Investments Internet Services Piano Software, Inc. Series C-1 Preferred Shares (418,527 shares) Initial Acquisition Date 12/22/20212023-12-310001508655Equity and Other Investments Pharmaceuticals TherapeuticsMD, Inc. 65,250 Warrants Initial Acquisition Date 7/29/20222022-12-310001508655us-gaap:IncomeApproachValuationTechniqueMembertslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputDiscountRateMember2023-12-310001508655Derivative Interest Rate Swap2023-12-310001508655Equity and Other Investments Oil, Gas and Consumable Fuels TRP Assets, LLC Partnership Interest (1.89% ownership) Initial Acquisition Date 8/25/20222022-01-012022-12-310001508655Debt Investments Business services ExtraHop Networks, Inc. First-lien loan ($57,950 par, due 7/2027) Initial Acquisition Date 7/22/2021 Reference Rate and Spread L + 7.50% Interest Rate 12.23%2022-12-310001508655tslx:TwentyTwentySixNotesMember2021-12-310001508655us-gaap:IncomeApproachValuationTechniqueMembertslx:MezzanineDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMemberus-gaap:MeasurementInputDiscountRateMember2023-12-310001508655tslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputComparabilityAdjustmentMembersrt:WeightedAverageMemberus-gaap:MarketApproachValuationTechniqueMember2022-12-310001508655us-gaap:IncomeApproachValuationTechniqueMembertslx:FirstLienDebtInvestmentsMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMemberus-gaap:MeasurementInputDiscountRateMember2022-12-310001508655tslx:RealizedCapitalGainsAccruedPriorToMarchThirtyFirstTwoThousandFourteenMembertslx:InvestmentAdvisoryAgreementMember2011-04-152011-04-150001508655tslx:DelayedDrawAndRevolverMembertslx:KyribaCorpMember2023-12-310001508655Debt 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%2023-01-012023-12-310001508655Equity and Other Investments Structured Credit Bain Capital Credit CLO Ltd, Series 2018-1A Structured Product ($500 par, due 4/2031) Initial Acquisition Date 10/15/2020 Reference Rate and Spread L + 5.35% Interest Rate 8.13%2022-12-310001508655Debt 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%2023-12-310001508655Equity and Other Investments Structured Credit Wind River CLO Ltd, Series 2018-3A Structured Product ($2,000 par, due 1/2031) Initial Acquisition Date 12/12/2022 Reference Rate and Spread L + 5.65% Interest Rate 6.46%2022-12-310001508655Debt Investments Financial Services Kyriba Corp. First-lien loan (EUR 9,924 par, due 4/2025) Initial Acquisition Date 4/9/2019 Reference Rate and Spread E + 9.00% Interest Rate 11.20% (incl. 9.00% PIK)2022-12-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. Series D Preferred Shares (1,240,740 shares) Initial Acquisition Date 5/11/20212022-01-012022-12-310001508655Debt Investments Business services WideOrbit, Inc. First-lien loan ($35,548 par, due 7/2025) Initial Acquisition Date 7/8/2020 Reference Rate and Spread L + 8.50% Interest Rate 12.88%2022-12-310001508655tslx:SecondLienDebtInvestmentsMember2023-01-012023-12-310001508655Debt 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 12.60%2023-01-012023-12-310001508655Debt 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%2023-01-012023-12-310001508655tslx:SecondLienDebtInvestmentsMember2022-12-310001508655tslx:FirstLienDebtInvestmentsMember2023-12-310001508655Debt Investments Financial Services2022-12-310001508655Interest Rate Swap Company Pays SOFR + 2.72% Maturity Date 11/1/20242023-12-310001508655Equity and Other Investments Education RMCF IV CIV XXXV, LP. Partnership Interest (11.94% ownership) Initial Acquisition Date 6/8/20212023-12-310001508655tslx:EquityAndOtherInvestmentsMember2023-12-310001508655Debt 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 8.26%2022-12-310001508655Debt 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%2023-12-310001508655Non-controlled, Affiliated Investments2021-12-3100015086552022-01-012022-12-310001508655Debt 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% (PIK)2023-01-012023-12-310001508655Equity and Other Investments Retail and Consumer Products American Achievement, Corp. Class A Units (687 units) Initial Acquisition Date 3/16/20212022-01-012022-12-310001508655Debt Investments Hotel, Internet Services SMA Technologies Holdings, LLC First-lien loan ($36,833 par, due 10/2028) Initial Acquisition Date 10/31/2022 Reference Rate Spread SOFR + 6.75% Interest Rate 11.07%2022-12-310001508655Debt Investments Hotel, Internet Services Piano Software, Inc First-lien loan ($51,312 par, due 2/2026) Initial Acquisition Date 2/25/2021 Reference Rate Spread SOFR + 7.10% Interest Rate 11.42%2022-12-310001508655tslx:TwoThousandTwentyTwoConvertibleNotesMember2017-02-280001508655Debt 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%2023-12-310001508655Equity and Other Investments Retail and Consumer Products Copper Bidco, LLC Trust Certificates (132,928 Certificates) Initial Acquisition Date 12/7/20202023-12-310001508655Debt Investments Retail and Consumer Products Neuintel, LLC First-lien loan ($56,400 par, due 12/2026) Initial Acquisition Date 12/20/2021 Reference Rate and Spread L + 6.25% Interest Rate 10.76%2022-01-012022-12-3100015086552024-02-150001508655Equity and Other Investments Retail and Consumer Products Copper Bidco, LLC Trust Certificates (996,958 Certificates) Initial Acquisition Date 1/30/20212023-01-012023-12-310001508655Equity 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%2023-01-012023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:EmploymentHeroHoldingsPtyLtdMember2022-12-310001508655us-gaap:RevolvingCreditFacilityMembersrt:ObligorGroupMembersrt:MinimumMember2023-12-310001508655us-gaap:SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMembertslx:TwoThousandTwentyNineNotesMember2023-01-012023-12-310001508655tslx:RevolverMembertslx:IRGSEHoldingCorpMember2022-12-310001508655us-gaap:CommonStockMember2023-05-150001508655tslx:DelayedDrawMembertslx:SlBuyerCorpMember2023-12-310001508655us-gaap:FairValueInputsLevel3Membertslx:SecondLienDebtInvestmentsMember2023-12-310001508655Debt Investments Financial Services TradingScreen, Inc. First-lien loan ($44,663 par, due 4/2027) Initial Acquisition Date 4/30/2021 Reference Rate and Spread L + 6.25% Interest Rate 10.66%2022-12-310001508655tslx:MezzanineDebtInvestmentsMember2023-01-012023-12-310001508655Debt Investments Hotel, Internet Services Workwell Bayshore Intermediate #2, L. First-lien revolving loan ($780 par, due 10/2027) Initial Acquisition Date 10/1/2021 Reference Rate Spread L + 7.75% Interest Rate 10.89%2022-01-012022-12-310001508655Debt Investments Hotel, Gaming and Leisure ASG II, LLC First-lien loan ($58,048 par, due 5/2028) Initial Acquisition Date 5/25/2022 Reference Rate and Spread SOFR + 6.35% Interest Rate 10.67%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 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%2023-12-310001508655Debt 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:SupplementalDividendMember2021-05-042021-05-040001508655Equity and Other Investments Structured Credit Eaton CLO Ltd, Series 2015-1A Structured Product ($2,500 par, due 1/2030) Initial Acquisition Date 6/23/2022 Reference Rate and Spread L + 2.50% Interest Rate 5.21%2022-01-012022-12-310001508655tslx:TwentyTwentyThreeNotesMember2018-01-012018-01-310001508655Equity 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 Human Resource Support Services Employment Hero Holdings Pty Ltd. Series E Preferred Shares (113,250 shares) Initial Acquisition Date 3/1/20222023-12-310001508655Debt Investments2022-12-310001508655Equity and Other Investments Structured Credit Battalion CLO Ltd, Series 2021-21A Structured Product ($1,300 par, due 7/2034) Initial Acquisition Date 7/13/2022 Reference Rate and Spread L + 3.30% Interest Rate 5.81%2022-12-310001508655Debt Investments, Transportation, Project44, Inc, First-lien revolving 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:CarlstarGroupLLCMembertslx:RevolverMember2022-12-310001508655srt:MaximumMembertslx:TwoThousandTwentyThreeNotesMember2022-12-310001508655Debt Investments Financial Services G Treasury SS, LLC First-lien loan ($65,859 par, due 4/2024) Initial Acquisition Date 4/9/2018 Reference Rate and Spread SOFR + 8.40% Interest Rate 12.94%2022-01-012022-12-310001508655tslx:EquityAndOtherInvestmentsMembertslx:AssetValuationWaterfallMemberus-gaap:FairValueInputsLevel3Member2023-12-310001508655Debt 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%2023-12-310001508655Equity 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 8.56%2023-12-310001508655tslx:RevolverMembertslx:EMSLinqIncMember2023-12-310001508655tslx:SupplementalDividendMember2023-05-080001508655Debt Investments Education2022-12-310001508655us-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMembersrt:MinimumMemberus-gaap:MeasurementInputDiscountRateMember2022-12-310001508655Equity and Other Investments Structured Credit Ares CLO Ltd, Series 2021-59A StructuredProduct ($1,000par,due4/2034) Initial Acquisition Date 6/23/2022 Reference Rate and Spread SOFR+6.51% Interest Rate 11.89%2023-12-310001508655Debt 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% PIK2023-12-310001508655Debt 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 Healthcare Caris Life Sciences, Inc. First-lien loan ($5,000 par, due 9/2023) Initial Acquisition Date 9/21/2018 Reference Rate and Spread 11.30% Interest Rate 11.30%2022-12-310001508655Debt 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%2023-01-012023-12-310001508655tslx:TwoThousandTwentyFourNotesMember2023-12-310001508655tslx:TwentyTwentyTwoConvertibleNotesMember2023-01-012023-12-310001508655Equity and Other Investments Pharmaceuticals TherapeuticsMD, Inc. 14,256 Warrants Initial Acquisition Date 8/5/20202022-12-310001508655Debt Investments, Manufacturing, 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%2023-12-310001508655tslx:OfficeProductsMember2022-12-310001508655tslx:ConvertibleSeniorNotesDueTwentyTwentyTwoMember2020-12-310001508655Interest Rate Swap Company Receives L + 2.11% Company Pays 4.50% Maturity Date 8/1/2022 One2022-01-012022-12-310001508655tslx:SupplementalDividendMember2023-02-162023-02-160001508655Debt 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%2023-01-012023-12-310001508655us-gaap:CommonStockMember2021-01-012021-12-310001508655Equity and Other Investments Marketing Services Validity, Inc. Series A Preferred Shares (3,840,000 shares) Initial Acquisition Date 5/31/20182022-12-310001508655Debt 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 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 Hotel, Gaming and Leisure ASG II, LLC First-lien loan ($58,048 par, due 5/2028) Initial Acquisition Date 5/25/2022 Reference Rate and Spread SOFR + 6.35% Interest Rate 10.67%2022-01-012022-12-310001508655Debt 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%2023-12-310001508655us-gaap:CommonStockMember2022-12-310001508655Equity and Other Investments Structured Credit CarVal CLO III Ltd, Series 2019-2A Structured Product ($1,000 par, due 7/2032) Initial Acquisition Date 6/30/2022 Reference Rate and Spread L + 6.44% Interest Rate 9.15%2022-01-012022-12-310001508655tslx:FirstLienDebtInvestmentsMember2022-01-012022-12-310001508655Debt 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)2023-01-012023-12-310001508655Debt 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:TwentyTwentyNineNotesMember2023-01-012023-12-310001508655tslx:DelayedDrawMembertslx:BanyanSoftwareHoldingsLlcMember2023-12-310001508655Debt 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 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%2023-12-310001508655Debt 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)2023-01-012023-12-310001508655tslx:RevolverMembertslx:DyeDurhamCorpMember2022-12-310001508655Debt Investments Financial Services Jonas Collections and Recovery, Inc. First-lien loan ($19,125 par, due 6/2026) Initial Acquisition Date 6/21/2021 Reference Rate and Spread L + 5.25% Interest Rate 10.40%2022-12-310001508655us-gaap:IncomeApproachValuationTechniqueMemberus-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMemberus-gaap:MeasurementInputDiscountRateMembersrt:WeightedAverageMember2022-12-310001508655country:DE2023-12-310001508655Debt Investments Financial Services Kyriba Corp. First-lien loan ($19,051 par, due 4/2025) Initial Acquisition Date 4/9/2019 Reference Rate and Spread L + 9.00% Interest Rate 13.73% (incl. 9.00% PIK)2022-01-012022-12-310001508655tslx:SupplementalDividendMember2022-02-170001508655tslx:SupplementalDividendMember2023-05-082023-05-080001508655tslx:SupplementalDividendMember2021-02-170001508655tslx:RisksRelatedToOurBusinessAndStructureMember2023-01-012023-12-310001508655Debt Investments Business services ReliaQuest Holdings, LLC First-lien loan ($63,477 par, due 10/2026) Initial Acquisition Date 10/8/2020 Reference Rate and Spread SOFR + 7.25% Interest Rate 11.83%2022-01-012022-12-310001508655Debt Investments Human Resource Support Services PageUp People, Ltd. First-lien loan (GBP 3,766 par, due 12/2025) Initial Acquisition Date 10/28/2021 Reference Rate and Spread S + 5.62% Interest Rate 8.55%2022-01-012022-12-310001508655Equity and Other Investments Hotel, Gaming and Leisure IRGSE Holding Corp. Class A Units (33,790,171 units) Initial Acquisition Date 12/21/20182022-12-3100015086552021-02-232021-02-230001508655Debt Investments Financial Services2023-12-310001508655Interest Rate Swap Company Pays SOFR + 2.99% Maturity Date 8/14/20282023-12-310001508655Debt Investments Business services Netwrix Corp. First-lien loan ($36,119 par, due 6/2029) Initial Acquisition Date 6/9/2022 Reference Rate and Spread SOFR + 5.00% Interest Rate 9.7%2022-01-012022-12-310001508655tslx:DelayedDrawMembertslx:AlphaMidcoIncMember2023-12-310001508655Debt Investments Business Services Wrangler TopCo, LLC First-lien loan ($4,043,546 par, due 7/2029) Initial Acquisition Date 7/7/2023 Reference Rate and Spread SOFR + 7.50% Interest Rate 12.88%2023-01-012023-12-310001508655Equity 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%2023-12-310001508655Equity and Other Investments Structured Credit CIFC CLO Ltd, Series 2021-4A Structured Product ($1,000 par, due 7/2033) Initial Acquisition Date 7/14/2022 Reference Rate and Spread L + 6.00% Interest Rate 8.51%2022-12-310001508655Debt Investments Hotel, Gaming and Leisure2023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:NetwrixCorpMember2022-12-310001508655Debt Investments Communications Banyan Software Holdings, LLC First-lien loan ($29,739 par, due 10/2026) Initial Acquisition Date 1/7/2023 Reference Rate and Spread SOFR + 7.35% Interest Rate 12.71%2023-01-012023-12-310001508655tslx:TwoThousandTwentySixNotesMembertslx:ThreeMonthLiborMember2022-01-012022-12-310001508655tslx:SecondLienDebtInvestmentsMember2022-01-012022-12-310001508655Equity 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%2023-01-012023-12-310001508655Debt Investments Business services Alpha Midco, Inc. First-lien loan ($68,720 par, due 8/2025) Initial Acquisition Date 8/15/2019 Reference Rate and Spread SOFR + 7.63% Interest Rate 12.21%2022-12-310001508655Equity and Other Investments Communications2023-12-310001508655Interest Rate Swap Company Pays L + 1.99% Maturity Date 1/22/20232022-12-310001508655tslx:ReliaQuestHoldingsLLCMembertslx:DelayedDrawRevolverPreferredEquityMember2023-12-310001508655tslx:StructuredCreditInvestmentsMember2023-01-012023-12-310001508655Debt 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%2023-12-310001508655tslx:TwoThousandTwentyFourNotesMemberus-gaap:SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember2023-01-012023-12-310001508655Interest Rate Swap2 Company Receives L + 2.11% Maturity Date 8/1/20222022-12-310001508655Debt Investments Education Destiny Solutions Parent Holding Company First-lien loan ($60,000 par, due 6/2026) Initial Acquisition Date 6/8/2021 Reference Rate and Spread L + 5.75% Interest Rate 10.13%2022-01-012022-12-310001508655Equity and Other Investments Structured Credit Benefit Street Partners CLO Ltd, Series 2015-BR Structured Product ($2,500 par, due 7/2034) Initial Acquisition Date 7/13/2022 Reference Rate and Spread L + 3.85% Interest Rate 6.56%2022-01-012022-12-310001508655Equity and Other Investments Business Services ReliaQuest, LLC Class A-2 Units (2,580 units) Initial Acquisition Date 6/21/20222022-12-310001508655Debt 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%2023-01-012023-12-310001508655Debt 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)2023-12-310001508655Debt Investments Education Destiny Solutions Parent Holding Company First-lien loan ($60,000 par, due 6/2026) Initial Acquisition Date 6/8/2021 Reference Rate and Spread L + 5.75% Interest Rate 10.13%2022-12-310001508655Interest Rate Swap Company Receives SOFR + 2.54% Maturity Date 11/1/20242023-01-012023-12-310001508655Equity and Other Investments Structured Credit Jefferson Mill CLO Ltd, Series 2015-1A Structured Product ($1,000 par, due 10/2031) Initial Acquisition Date 5/23/2022 Reference Rate and Spread L + 3.55% Interest Rate 6.26%2022-12-310001508655tslx:DelayedDrawMembertslx:BearOpCoLLCMember2023-12-310001508655tslx:NortheastMember2022-12-310001508655Equity and Other Investments Structured Credit GoldenTree CLO Ltd, Series 2020-7A Structured Product ($1,000 par, due 4/2034) Initial Acquisition Date 6/17/2022 Reference Rate and Spread L + 6.50% Interest Rate 9.21%2022-12-310001508655tslx:DelayedDrawAndMembershipInterestMembertslx:TRPAssetsLLCMember2022-12-310001508655Controlled Affiliated Investments IRGSE Holding Corp.2022-12-310001508655Debt Investments Hotel, Internet Services Higher Logic, LLC First-lien loan ($55,820 par, due 1/2025) Initial Acquisition Date 6/18/2018 Reference Rate Spread SOFR + 7.25% Interest Rate 11.83%2022-01-012022-12-310001508655us-gaap:FairValueInputsLevel3Member2023-12-310001508655Debt Investments Healthcare Raptor US Buyer II Corp. First-lien loan ($15,569 par,due3/2029) Initial Acquisition Date 3/24/2023 Reference Rate and Spread SOFR + 6.75% Interest Rate 12.10%2023-01-012023-12-310001508655tslx:DelayedDrawMembertslx:OutsystemsLuxcoMember2023-12-310001508655tslx:InterestRateSwapTwoMember2023-01-012023-12-310001508655tslx:ChemicalsMember2022-12-310001508655Debt Investments Hotel, Internet Services LeanTaaS Holdings, Inc. First-lien loan ($27,782 par, due 7/2028) Initial Acquisition Date 7/12/2022 Reference Rate Spread SOFR + 7.50% Interest Rate 12.08%2022-12-310001508655tslx:RetailAndConsumerProductsMember2022-12-310001508655tslx:ConvertibleSeniorNotesDueTwentyTwentyTwoMember2021-12-310001508655tslx:AdviserMemberus-gaap:GeneralAndAdministrativeExpenseMembertslx:AdministrationAgreementMember2023-01-012023-12-310001508655Equity 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%2023-01-012023-12-310001508655tslx:TwoThousandTwentySixNotesMember2021-02-030001508655tslx:NonControlledNonAffiliatedInvestmentsMember2023-01-012023-12-310001508655tslx:SupplementalDividendMember2022-05-030001508655tslx:HirevueIncMembertslx:RevolverMember2023-12-310001508655tslx:InterestRateSwapNineMember2022-01-012022-12-310001508655Debt 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%2023-12-310001508655Debt Investments Education EMS Linq, Inc. First-lien loan ($56,216 par, due 12/2027) Initial Acquisition Date 12/22/2021 Reference Rate and Spread L + 6.25% Interest Rate 10.63%2022-01-012022-12-3100015086552022-09-300001508655us-gaap:RetainedEarningsMembersrt:CumulativeEffectPeriodOfAdoptionAdjustmentMember2020-12-310001508655tslx:AssetValuationWaterfallMemberus-gaap:FairValueInputsLevel3Membertslx:MezzanineDebtInvestmentsMember2022-12-310001508655tslx:WideOrbitIncMembertslx:RevolverMember2022-12-310001508655Debt Investments Healthcare2022-12-310001508655Debt Investments Hotel, Gaming and Leisure IRGSE Holding Corp First-lien revolving loan ($16,747 par, due 6/2023) Initial Acquisition Date 9/29/2015 Reference Rate and Spread L + 9.50% Interest Rate 14.23%2022-01-012022-12-310001508655Equity and Other Investments2023-12-310001508655Total Investments2022-12-310001508655tslx:EquityAndOtherInvestmentsMemberus-gaap:FairValueInputsLevel3Member2023-01-012023-12-310001508655Equity and Other Investments Education Astra 2L Holdings II LLC Membership Interest (10.17% ownership) Initial Acquisition Date 1/13/20222023-12-310001508655tslx:TwentyTwentyThreeNotesMember2020-12-310001508655Interest Rate Swap Company Receives 3.875% Company SOFR + 2.51% Maturity Date 11/1/20242023-01-012023-12-310001508655Equity and Other Investments Financial Services Passport Labs, Inc. 17,534 Warrants Initial Acquisition Date 4/28/20212023-12-310001508655country:AU2022-12-310001508655tslx:TwentyTwentyFourNotesMember2020-02-052020-02-050001508655Equity 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%2023-12-310001508655Interest Rate Swap Company Receives 4.50% Company Pays L + 199% Maturity Date 1/22/20232022-01-012022-12-310001508655Equity and Other Investments Business Services Dye & Durham, Ltd. Common Shares (126,968 shares) Initial Acquisition Date 12/3/20212022-12-310001508655tslx:SupplementalDividendMember2023-02-160001508655Equity 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 L + 2.60% Interest Rate 5.11%2022-12-310001508655Equity and Other Investments Healthcare Raptor US Buyer II Corp. 20,268 Ordinary Shares Initial Acquisition Date 3/24/20232023-12-310001508655tslx:BaseDividendMember2023-11-020001508655Debt Investments Financial Services Ibis US Blocker Co. First-lien loan ($13,957 par, due 5/2028) Initial Acquisition Date 5/28/2021 Reference Rate and Spread L + 8.25% Interest Rate 12.98% PIK2022-01-012022-12-310001508655Interest Rate Swap Company Pays L + 2.37% Maturity Date 8/1/20222022-12-310001508655Debt 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%2023-12-310001508655tslx:DelayedDrawAndRevolverMembertslx:ElysianFincoLtdMember2022-12-310001508655Debt 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% (PIK)2023-01-012023-12-310001508655Debt Investments Human Resource Support Services PageUp People, Ltd. First-lien loan (AUD 14,520 par, due 12/2025) Initial Acquisition Date 1/11/2018 Reference Rate and Spread B + 5.50% Interest Rate 9.28%2022-01-012022-12-310001508655Debt Investments Communications2022-12-310001508655Debt Investments Chemicals Erling Lux Bidco SARL First-lien loan (GBP 10,217 par, due 9/2028) Initial Acquisition Date 9/6/2022 Reference Rate and Spread S + 6.75% Interest Rate 10.20%2022-01-012022-12-310001508655tslx:DelayedDrawMembertslx:SkylarkUkDebtcoLimitedMember2023-12-310001508655us-gaap:NondesignatedMemberus-gaap:InterestRateSwapMember2023-01-012023-12-310001508655Debt Investments Mach Natural Resource 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 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, Manufacturing,2023-12-310001508655Equity 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 L + 8.00% Interest Rate 10.17%2022-12-310001508655Debt Investments Financial Services PrimeRevenue, Inc. First-lien loan ($22,507 par, due 12/2023) Initial Acquisition Date 12/31/2018 Reference Rate and Spread L + 7.00% Interest Rate 11.38%2022-01-012022-12-310001508655tslx:RevolvingCreditFacilityMaturityOnApril232027Member2023-01-012023-12-310001508655tslx:CapitalGainsAccrueFollowingMarchThirtyFirstTwoThousandFourteenMembertslx:InvestmentAdvisoryAgreementMember2011-04-152011-04-150001508655us-gaap:RevolvingCreditFacilityMember2022-12-310001508655Debt Investments Business services Information Clearinghouse, LLC and MS Market Service, LLC First-lien loan ($17,820 par, due 12/2026) Initial Acquisition Date 12/20/2021 Reference Rate and Spread SOFR + 6.65% Interest Rate 11.16%2022-12-310001508655Equity and Other Investments Structured Credit RR Ltd, Series 2020-8A Structured Product ($1,000 par, due 4/2033) Initial Acquisition Date 8/22/2022 Reference Rate and Spread L + 6.40% Interest Rate 8.91%2022-12-310001508655Equity and Other Investments Structured Credit Gulf Stream Meridian, Series 2021-4A Structured Product ($1,015 par, due 7/2034) Initial Acquisition Date 6/3/2022 Reference Rate and Spread L + 6.35% Interest Rate 8.86%2022-01-012022-12-310001508655Equity and Other Investments Healthcare Caris Life Sciences, Inc. Series D Preferred Shares (1,240,740 shares) Initial Acquisition Date 5/11/20212022-12-310001508655tslx:FirstLienDebtInvestmentsMember2022-12-310001508655Debt Investments Retail and Consumer Products American Achievement, Corp. First-lien loan ($27,171 par, due 9/2026) Initial Acquisition Date 9/30/2015 Reference Rate and Spread L + 6.25 % Interest Rate 10.38% (incl. 9.88% PIK)2022-01-012022-12-310001508655Debt Investments Business services Acceo Solutions, Inc. First-lien loan (CAD 57,353 par, due 10/2025) Initial Acquisition Date 7/6/2018 Reference Rate and Spread C + 4.75% Interest Rate 9.49%2022-12-310001508655Equity and Other Investments Structured Credit Carlyle Global Market Strategies CLO Ltd, Series 2018-1A Structured Product ($1,550 par, due 4/2031) Initial Acquisition Date 8/11/2020 Reference Rate and Spread L + 5.75% Interest Rate 8.46%2022-01-012022-12-310001508655Debt 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 12.60%2023-12-310001508655tslx:InvestmentAdvisoryAgreementMember2022-01-012022-12-310001508655Equity and Other Investments Business Services Newark FP Co-Invest, L.P. Partnership (2,527,719 units) Initial Acquisition Date 11/8/20232023-12-310001508655Equity 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%2023-01-012023-12-310001508655Debt 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 7.74%2022-12-310001508655Debt 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%2023-01-012023-12-310001508655tslx:TwoThousandTwentyFourNotesMember2020-12-3100015086552021-10-012021-12-310001508655Debt 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%2023-12-31iso4217:AUDiso4217:EURxbrli:purexbrli:sharesiso4217:CADiso4217:GBPiso4217:USDxbrli:sharesiso4217:USDtslx:Investment