10-K 1 bcsf-20231231.htm 10-K 10-K
Jun. 16, 2021false0001655050Jun. 28, 2022FYApr. 02, 2019Mar. 22, 2021May 03, 2019Feb. 05, 2021Feb. 28, 2023Dec. 22, 2020Mar. 23, 2021Oct. 01, 20185.50Sep. 03, 2019Mar. 08, 2022Aug. 28, 2018--12-31http://fasb.org/us-gaap/2023#ForeignExchangeForwardMemberhttp://fasb.org/us-gaap/2023#ForeignExchangeForwardMember333P2DP2D0001655050bcsf:NonControlledAffiliatedEntityMemberbcsf:FirstLienSeniorSecuredLoanDelayedDrawMemberbcsf:DirectTravelIncMember2022-12-310001655050Non-controlled/Non-Affiliated Investments High Tech Industries CB Nike IntermediateCo Ltd First Lien Senior Secured Loan - Revolver Maturity Date 10/31/20252023-12-3100016550502020-03-202020-03-200001655050Non-controlled/Non-Affiliated Investments Services: Business Darcy Partners First Lien Senior Secured Loan - Revolver2022-12-310001655050bcsf:InterestRateFloorFiveMember2023-12-310001655050Non-controlled/Non-Affiliated Investments Capital Equipment AXH Air Coolers First Lien Senior Secured Loan - Delayed Draw Maturity Date 10/31/20292023-12-310001655050Investment MZR Aggregator Acquisition Date 12/22/20202023-01-012023-12-310001655050bcsf:NonControlledAffiliatedEntityMemberbcsf:DirectTravelIncOneMemberbcsf:FirstLienSeniorSecuredLoanDelayedDrawMember2023-01-012023-12-310001655050Controlled Affiliate Investments Investment Vehicles International Senior Loan Program, LLC Subordinated Note Investment Vehicles SOFR Spread 8.00% Interest Rate 13.55% Maturity Date 2/22/20282023-12-3100016550502020-03-200001655050bcsf:InternationalSeniorLoanProgramLlcMemberCanadian Dollar Retail New Look Vision Group First Lien Senior Secured Loan - Delayed Draw CDOR Spread 5.50% Interest Rate 10.93% Maturity Date 5/26/20282023-12-310001655050Non-controlled/Non-Affiliate Investments Healthcare & Pharmaceuticals CB Titan Holdings, Inc. 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First Lien Senior Secured Loan – Revolver Maturity Date 5/12/20252023-12-310001655050DC Blox Inc,Preferred Equity2023-01-012023-06-300001655050bcsf:NonControlledAffiliatedEntityMemberbcsf:EquityInterestMemberbcsf:DirectTravelIncMember2022-01-012022-12-310001655050bcsf:LegacyCorporateLendingHoldcoLlcMemberbcsf:ControlledAffiliatedEntityMemberbcsf:EquityInterestMember2023-12-310001655050us-gaap:InvestmentAffiliatedIssuerNoncontrolledMember2022-01-012022-12-310001655050Non-controlled/Non-Affiliated Investments Chemicals, Plastics & Rubber V Global Holdings LLC First Lien Senior Secured Loan - Revolver SOFR Spread 5.85% Interest Rate 11.21% Maturity Date 12/22/20252023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMember2023-12-310001655050us-gaap:EquitySecuritiesMemberus-gaap:FairValueInputsLevel3Member2022-12-310001655050bcsf:ValuationTechniqueCollateralCoverageAnalysisMemberbcsf:FirstLienSeniorSecuredLoansFiveMemberus-gaap:FairValueInputsLevel3Memberbcsf:MeasurementInputRecoveryRateMember2022-12-310001655050Non-controlled/Non-Affiliate Investments FIRE: Insurance Paisley Bidco Limited First Lien Senior Secured Loan- Revolver EURIBOR Spread 5.50 % Interest Rate 7.11% Maturity Date 11/26/20282022-12-310001655050Non-controlled/Non-Affiliate Investments High Tech Industries Appriss Holdings, Inc. 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First Lien Senior Secured Loan - Revolver Maturity Date 7/6/20282022-12-310001655050Non-controlled/Non-Affiliated Investments FIRE: Insurance Paisley Bidco Limited First Lien Senior Secured Loan - Revolver EURIBOR Spread 5.50% Interest Rate 9.45% Maturity Date 11/26/20282023-12-310001655050bcsf:FirstLienSeniorSecuredLoanMemberbcsf:NonControlledAffiliatedEntityMemberbcsf:BlackbrushOilGasL.pMember2021-12-310001655050Non-controlled/Non-Affiliated Investments Automotive American Trailer Rental Group Subordinated Debt Spread 9.00% (4.50% PIK) Interest Rate 13.50% Maturity Date 12/1/20272023-12-310001655050us-gaap:FairValueInputsLevel2Memberbcsf:Notes2.55PercentDueOctober2026Member2023-12-310001655050Non-controlled/Non-Affiliated Investments Media: Advertising, Printing & Publishing Kpler First Lien Senior Secured Loan SONIA Spread 6.50% Interest Rate 11.69% Maturity Date 3/3/20302023-12-310001655050Investment Insigneo Financial Group LLC Acquisition Date 8/1/20222022-01-012022-12-310001655050Non-controlled/Non-Affiliated Investments Transportation: Cargo Grammer Purchaser, Inc. First Lien Senior Secured Loan LIBOR Spread 4.50% Interest Rate 9.72% Maturity Date 9/30/20242022-12-310001655050Non-controlled/Non-Affiliate Investments Titan Cloud Software, Inc First Lien Senior Secured Loan - Revolver Maturity Date 9/7/20282022-12-310001655050Non-controlled/Non-Affiliated Investments Construction & Building Service Master Equity Interest2023-12-310001655050bcsf:DelayedDrawCommitmentMemberbcsf:GillsPointSMember2023-12-310001655050Non-controlled/Non-Affiliate Investments FIRE: Finance Parmenion First Lien Senior Secured Loan SONIA Spread 5.75% Interest Rate 8.68% Maturity Date 5/11/20292022-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Three Morgan Stanley Settlement Date 01/17/20242023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Morgan Stanley Settlement Date 06/12/20252023-12-310001655050country:LU2023-01-012023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMember2023-01-012023-12-310001655050Non-controlled/Non-Affiliated Investments Transportation: Cargo A&R Logistics, Inc. First Lien Senior Secured Loan - Revolver SOFR Spread 6.00% Interest Rate 9.99% Maturity Date 5/5/20252022-12-310001655050Non-controlled/Non-Affiliate Investments Healthcare & Pharmaceuticals CPS Group Holdings, Inc. First Lien Senior Secured Loan - Revolver Maturity Date 3/3/20252022-12-3100016550502021-07-302021-07-300001655050bcsf:InternationalSeniorLoanProgramLlcMemberForward Foreign Currency Exchange Contracts Counterparty Standard Chartered Settlement Date 3/9/20232022-01-012022-12-310001655050Non-controlled/Non-Affiliated Investments Services: Business Elevator Holdco Inc. Equity Interest2023-12-310001655050Non-controlled/Non-Affiliated Investments Aerospace & Defense Forming Machining Industries Holdings, LLC First Lien Senior Secured Loan LIBOR Spread 8.25% Interest Rate 12.98% Maturity Date 10/9/20262022-12-310001655050Investment Lightning Holdings B, LLC Acquisition Date 1/2/20202023-01-012023-12-310001655050bcsf:BCSFAdvisorsLpMember2022-12-310001655050Non-controlled/Non-Affiliated Investments Transportation: Cargo RoadOne First Lien Senior Secured Loan SOFR Spread 6.25% Interest Rate 10.81% Maturity Date 12/29/20282022-12-310001655050bcsf:ElevenSoftwareMemberbcsf:RevolverCommitmentMember2022-12-310001655050bcsf:ControlledAffiliatedEntityMemberbcsf:GaleAviationOffshoreCoMemberbcsf:EquityInterestMember2022-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Bank of New York Mellon Settlement Date 7/28/20252023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Three Bank of New York Mellon Settlement Date 3/3/20232022-12-310001655050Non-controlled/Non-Affiliated Investments Services: Business SumUp Holdings Luxembourg S.à.r.l. First Lien Senior Secured Loan EURIBOR Spread 8.25% Interest Rate 12.21% Maturity Date 2/17/20262023-12-310001655050bcsf:Notes8.50PercentDue2023Member2022-09-060001655050Investment Appriss Holdings, Inc. Acquisition Date 5/3/20212022-01-012022-12-310001655050Non-controlled/Non-Affiliated Investments Services: Business Spring Finco BV First Lien Senior Secured Loan - Delayed Draw Maturity Date 7/15/20292023-12-310001655050Non-controlled/Non-Affiliated Investments Media: Diversified & Production 9 Story Media Group Inc. First Lien Senior Secured Loan CDOR Spread 5.25% Interest Rate 10.74% Maturity Date 4/30/20262023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Bank of New York Mellon Settlement Date 5/17/20242023-12-310001655050Controlled Affiliate Investments FIRE: Finance Legacy Corporate Lending HoldCo, LLC Preferred Equity2023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty One Standard Chartered Settlement Date 01/17/20242023-01-012023-12-310001655050Non-controlled/Non-Affiliated Investments Capital Equipment Ergotron Acquisition LLC First Lien Senior Secured Loan SOFR Spread 5.75% Interest Rate 10.18% Maturity Date 7/6/20282022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberU.S. Dollar Media: Diversified & Production Aptus 1724 Gmbh First Lien Senior Secured Loan LIBOR Spread 6.25% Interest Rate 10.97% Maturity Date 2/23/20282022-12-310001655050country:AU2023-01-012023-12-310001655050bcsf:TelecommunicationsSectorMemberbcsf:BainCapitalSeniorLoanProgramLlcMember2023-12-310001655050Non-controlled/Non-Affiliated Investments Automotive Cardo First Lien Senior Secured Loan SOFR Spread 5.15% Interest Rate 10.54% Maturity Date 5/12/20282023-12-310001655050Controlled Affiliate Investments Aerospace & Defense BCC Jetstream Holdings Aviation (On II), LLC First Lien Senior Secured Loan Spread 10.00% Interest Rate 10.00% Maturity Date 6/2/20242023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberBritish Pound FIRE: Finance Parmenion First Lien Senior Secured Loan SONIA Spread 5.50% Interest Rate 10.69% Maturity Date 5/11/20292023-12-310001655050bcsf:PreferredEquityInterestInvestmentVehicleMember2023-12-310001655050Consumer Goods: Non-Durable WU Holdco, Inc. First Lien Senior Secured Loan LIBOR Spread 5.50% Interest Rate 10.23% Maturity Date 3/26/2026 Onebcsf:BainCapitalSeniorLoanProgramLlcMember2022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberus-gaap:RelatedPartyMember2022-01-012022-12-310001655050FIRE: Insurance Margaux Acquisition Inc. First Lien Senior Secured Loan LIBOR Spread 5.75% Interest Rate 9.49% Maturity Date 12/19/2024bcsf:BainCapitalSeniorLoanProgramLlcMember2022-12-310001655050bcsf:TransportationCargoSectorMember2023-01-012023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberForward Foreign Currency Exchange Contracts Counterparty Morgan Stanley Settlement Date 3/27/20232022-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty One Morgan Stanley Settlement Date 06/10/20252023-01-012023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberForward Foreign Currency Exchange Contracts Counterparty One Morgan Stanley Settlement Date 3/27/20232022-01-012022-12-310001655050us-gaap:RevolvingCreditFacilityMember2020-05-150001655050Non-controlled/Non-Affiliated Investments Services: Business Parcel2Go Equity Interest2023-12-310001655050Non-controlled/Non-Affiliated Investments Telecommunications Meriplex Communications, Ltd. First Lien Senior Secured Loan - Delayed Draw SOFR Spread 5.10% Interest Rate 10.42% Maturity Date 7/17/20282023-12-310001655050Investment Armor Group, LP Acquisition Date 8/28/20182022-01-012022-12-310001655050Non-controlled/Non-Affiliated Investments Aerospace & Defense Forward Slope First Lien Senior Secured Loan – Revolver SOFR Spread 6.85% Interest Rate 12.17% Maturity Date 8/22/20292023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberTransportation: Cargo Omni Logistics, LLC First Lien Senior Secured Loan SOFR Spread 9.00% Interest Rate 13.69% Maturity Date 12/30/20272022-12-310001655050bcsf:BccJetstreamHoldingsAviationOffILlcMemberbcsf:ControlledAffiliatedEntityMemberbcsf:EquityInterestMember2022-12-310001655050bcsf:Notes8.50PercentDue2023Member2022-08-242022-08-240001655050bcsf:InterestRateFloorOneMember2023-12-310001655050Non-controlled/Non-Affiliated Investments Capital Equipment ClockSpring Second Lien Senior Secured Loan SOFR Spread 6.50% (5.00% PIK) Interest Rate 16.08% Maturity Date 8/1/20252022-12-310001655050Non-controlled/Non-Affiliated Investments Services: Business ImageTrend First Lien Senior Secured Loan - Revolver Maturity Date 1/31/20292023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Bank of New York Mellon Settlement Date 1/9/20252023-12-310001655050us-gaap:InvestmentAffiliatedIssuerNoncontrolledMember2023-12-310001655050Non-controlled/Non-Affiliated Investments Services: Business AMCP Clean Acquisition Company, LLC First Lien Senior Secured Loan - Delayed Draw SOFR Spread 4.40% Interest Rate 9.79% Maturity Date 6/16/20252023-12-310001655050bcsf:TelecommunicationsSectorMember2023-12-310001655050Non-controlled/Non-Affiliated Investments Automotive JHCC Holdings, LLC First Lien Senior Secured Loan - Revolver Maturity Date 9/9/20252023-12-310001655050Non-controlled/Non-Affiliated Investments High Tech Industries Onventis First Lien Senior Secured Loan - Delayed Draw EURIBOR Spread 7.50% Interest Rate 11.47% Maturity Date 1/12/20302023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberServices: Business Avalon Acquiror, Inc. First Lien Senior Secured Loan SOFR Spread 6.25% Interest Rate 10.83% Maturity Date 3/10/20282022-12-310001655050Investment HealthDrive Acquisition Date 8/18/20232023-01-012023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberServices: Business Avalon Acquiror, Inc. First Lien Senior Secured Loan SOFR Spread 6.25% Interest Rate 11.60% Maturity Date 3/10/20282023-12-310001655050Investment International Senior Loan Program, LLC Acquisition Date 2/22/20212022-01-012022-12-310001655050bcsf:FirstLienSeniorSecuredLoanMemberbcsf:NonControlledAffiliatedEntityMemberbcsf:AnsettAviationTrainingMember2023-01-012023-12-310001655050bcsf:SolarayLLCMemberbcsf:RevolverCommitmentMember2023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberHotel, Gaming & Leisure Pyramid Global Hospitality First Lien Senior Secured Loan SOFR Spread 8.00% Interest Rate 13.41% Maturity Date 1/19/20272023-12-310001655050Non-controlled/Non-Affiliated Investments Transportation: Cargo Omni Intermediate First Lien Senior Secured Loan SOFR Spread 5.15% Interest Rate 10.54% Maturity Date 11/23/20262023-12-310001655050bcsf:SimplicityMemberbcsf:RevolverCommitmentMember2023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberbcsf:ISLPCreditFacilityTrancheBMember2022-08-310001655050bcsf:Notes8.50PercentDue2023Member2021-07-160001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberbcsf:ContainersPackagingAndGlassMember2022-12-310001655050Non-controlled/Non-Affiliated Investments Consumer Goods: Durable Tangent Technologies Acquisition, LLC Second Lien Senior Secured Loan SOFR Spread 8.75% Interest Rate 12.95% Maturity Date 5/30/20282022-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberbcsf:InvestmentsOperationsMemberbcsf:InvestmentConcentrationRiskMemberbcsf:FiveLargestInvesteeMember2023-12-310001655050bcsf:PreferredEquityInterestInvestmentVehicleMember2023-01-012023-12-310001655050us-gaap:InvestmentAffiliatedIssuerNoncontrolledMember2022-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberHotel, Gaming & Leisure Saltoun First Lien Senior Secured Loan Spread 13.75% PIK Interest Rate 13.75% Maturity Date 4/11/20282023-12-310001655050bcsf:DelayedDrawCommitmentMemberbcsf:TaoglasMember2023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Four Standard Chartered Settlement Date 01/17/20242023-01-012023-12-310001655050currency:USDbcsf:InternationalSeniorLoanProgramLlcMemberbcsf:HighTechIndustriesMember2023-12-310001655050bcsf:ChemicalsPlasticsAndRubberMember2023-01-012023-12-3100016550502022-07-292022-07-290001655050Non-controlled/Non-Affiliate Investments FIRE: Insurance MRHT First Lien Senior Secured Loan EURIBOR Spread 5.50 % Interest Rate 7.06% Maturity Date 7/26/20282022-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Two Bank of New York Mellon Settlement Date 3/3/20232022-12-310001655050bcsf:NonControlledAffiliatedEntityMemberbcsf:DirectTravelIncOneMemberbcsf:FirstLienSeniorSecuredLoanDelayedDrawMember2022-12-310001655050bcsf:RevolverCommitmentMemberbcsf:MachAcquisitionRCMember2022-12-310001655050currency:USDbcsf:InternationalSeniorLoanProgramLlcMemberbcsf:ChemicalsPlasticsAndRubberMember2023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberbcsf:AerospaceAndDefenseSectorMember2022-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberHigh Tech Industries NearMap First Lien Senior Secured Loan SOFR Spread 7.25% Interest Rate 12.61% Maturity Date 12/9/20292023-12-310001655050Non-controlled/Non-Affiliated Investments Aerospace & Defense Saturn Purchaser Corp First Lien Senior Secured Loan – Revolver Maturity Date 7/22/20292023-12-310001655050Non-controlled/Non-Affiliated Investments Consumer Goods: Non-Durable Fineline Technologies, Inc. Equity Interest2022-12-310001655050Non-controlled/Non-Affiliated Investments High Tech Industries Revalize, Inc. Preferred Equity2023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberU.S. Dollar Consumer goods: Durable Stanton Carpet Second Lien Senior Secured Loan SOFR Spread 9.15% Interest Rate 14.56% Maturity Date 3/31/20282023-12-310001655050bcsf:MM222CreditFacilityMemberbcsf:BainCapitalSeniorLoanProgramLlcMember2022-08-240001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberbcsf:ClassCNotesTwoZeroTwoThreeOneNotesMember2023-12-310001655050Investment Elk Parent Holdings, LP Acquisition Date 11/1/20192023-01-012023-12-310001655050Non-controlled/Non-Affiliated Investments Capital Equipment Ergotron Acquisition LLC First Lien Senior Secured Loan SOFR Spread 5.75% Interest Rate 11.17% Maturity Date 7/6/20282023-12-3100016550502021-04-302021-04-300001655050bcsf:TransportationCargoMember2022-12-310001655050Non-controlled/Non-Affiliated Investments Media: Publishing OGH Bidco Limited First Lien Senior Secured Loan SONIA Spread 6.25% Interest Rate 7.44% Maturity Date 6/29/20292022-12-310001655050bcsf:NonControlledAffiliatedEntityMemberbcsf:EquityInterestMemberbcsf:AnsettAviationTrainingMember2023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberHealthcare & Pharmaceuticals Apollo Intelligence First Lien Senior Secured Loan SOFR Spread 5.75% Interest Rate 11.12% Maturity Date 5/31/20282023-12-310001655050Non-controlled/Non-Affiliate Investments High Tech Industries Access First Lien Senior Secured Loan SONIA Spread 5.25% Interest Rate 8.68% Maturity Date 6/4/20292022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberForward Foreign Currency Exchange Contracts Counterparty Three Standard Chartered Settlement Date 1/18/20232022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberbcsf:InterestRateFloorTwoMember2023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberBritish Pound Services: Business Opus2 First Lien Senior Secured Loan SONIA Spread 5.00% Interest Rate 7.96% Maturity Date 5/5/20282022-12-310001655050Investment DC Blox Inc. Acquisition Date 3/23/20212023-01-012023-12-310001655050Non-controlled/Non-Affiliated Investments Aerospace & Defense Mach Acquisition R/C First Lien Senior Secured Loan - Revolver LIBOR Spread 7.50% Interest Rate 11.96% Maturity Date 10/18/20262022-12-310001655050bcsf:FirstLienSeniorSecuredLoansFourMemberus-gaap:ValuationTechniqueDiscountedCashFlowMembersrt:MaximumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputDiscountRateMember2022-12-310001655050bcsf:FirstLienSeniorSecuredLoansMember2023-01-012023-12-310001655050Non-controlled/Non-Affiliated Investments Transportation: Cargo RoadOne First Lien Senior Secured Loan - Revolver SOFR Spread 6.25% Interest Rate 11.72% Maturity Date 12/29/20282023-12-310001655050Non-controlled/Non-Affiliated Investments Hotel, Gaming & Leisure Saltoun First Lien Senior Secured Loan - Revolver Spread 13.75% PIK Interest Rate 13.75% Maturity Date 4/11/20282023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberForward Foreign Currency Exchange Contracts Counterparty Nine Standard Chartered Settlement Date 1/18/20232022-12-310001655050Non-controlled/Non-Affiliated Investments High Tech Industries Revalize, Inc. First Lien Senior Secured Loan - Delayed Draw SOFR Spread 5.90% Interest Rate 11.25% Maturity Date 4/15/20272023-12-310001655050bcsf:Notes8.50PercentDue2023Member2020-06-102020-06-100001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberConsumer Goods: Durable TLC Purchaser, Inc First Lien Senior Secured Loan LIBOR Spread 6.25% (2.00% PIK) Interest Rate 11.02 Maturity Date 10/13/20252022-12-310001655050Non-controlled/Non-Affiliated Investments Containers, Packaging & Glass Iris Holding, Inc. First Lien Senior Secured Loan SOFR Spread 4.75% Interest Rate 10.23% Maturity Date 6/28/20282023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberCanadian Dollar Retail New Look Vision Group First Lien Senior Secured Loan - Delayed Draw CDOR Spread 5.50% Interest Rate 10.38% Maturity Date 5/26/20282022-12-310001655050bcsf:ServicesConsumerMember2022-01-012022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberus-gaap:RelatedPartyMember2023-01-012023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Seven Standard Chartered Settlement Date 01/17/20242023-12-310001655050Non-controlled/Non-Affiliated Investments High Tech Industries AQ Software Corporation Preferred Equity2023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberNorwegian Krone Services: Business Spring Finco BV First Lien Senior Secured Loan NIBOR Spread 5.50% Interest Rate 10.12% Maturity Date 7/15/20292023-12-310001655050bcsf:StructuredProductsMemberus-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputComparabilityAdjustmentMember2023-12-310001655050Investment Elk Parent Holdings, LP Acquisition Date 11/1/20192022-01-012022-12-310001655050bcsf:ApolloIntelligenceMemberbcsf:DelayedDrawCommitmentMember2022-12-310001655050Non-controlled/Non-Affiliated Investments Services: Consumer MZR Aggregator Equity Interest2022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberEuropean Currency FIRE: Insurance Paisley Bidco Limited First Lien Senior Secured Loan- Revolver EURIBOR Spread 5.50% Interest Rate 7.11% Maturity Date 11/26/20282022-12-310001655050bcsf:NonControlledAffiliatedEntityMemberbcsf:EquityInterestMemberbcsf:BlackbrushOilGasL.pMember2023-01-012023-12-3100016550502021-03-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberServices: Business WCI Gigawatt Purchaser First Lien Senior Secured Loan - Delayed Draw SOFR Spread 5.76% Interest Rate 11.13% Maturity Date 11/19/20272023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Bank of New York Mellon Settlement Date 6/21/20242023-01-012023-12-310001655050bcsf:GrammerPurchaserIncMemberbcsf:RevolverCommitmentMember2023-12-310001655050Investment Darcy Partners Acquisition Date 6/1/20222023-01-012023-12-310001655050bcsf:FirstLienSeniorSecuredLoanMemberbcsf:ControlledAffiliatedEntityMemberbcsf:BccJetstreamHoldingsAviationOnIiLlcMember2022-01-012022-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberbcsf:ClassBOneNotesTwoZeroTwoThreeOneNotesMember2023-01-012023-12-310001655050us-gaap:InvestmentUnaffiliatedIssuerMember2021-01-012021-12-310001655050us-gaap:ForeignExchangeForwardMemberbcsf:BankOfNewYorkMember2022-12-310001655050Non-controlled/Non-Affiliated Investments Automotive American Trailer Rental Group Subordinated Debt Spread 9.00% (2.00%PIK) Interest Rate 11.00% Maturity Date 12/1/2027 Two2022-12-310001655050bcsf:TLCPurchaserIncMemberbcsf:RevolverCommitmentMember2022-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Citibank Settlement Date 1/9/20232022-01-012022-12-310001655050Non-controlled/Non-Affiliated Investments Healthcare & Pharmaceuticals Datix Bidco Limited First Lien Senior Secured Loan - Revolver SONIA Spread 4.50% Interest Rate 9.69% Maturity Date 10/28/20242023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Bank of New York Mellon Settlement Date 5/17/20242022-12-310001655050us-gaap:RevolvingCreditFacilityMemberbcsf:LiborMember2021-01-012021-03-110001655050bcsf:ClasscRSeniorDeferrableFloatingRateNotesMember2021-11-302021-11-300001655050Controlled Affiliate Investments Cash Equivalents Goldman Sachs Financial Square Government Fund Institutional Share Class Cash Equivalents Interest Rate 5.25%2023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberBritish Pound Services: Business Brook Bidco First Lien Senior Secured Loan SONIA Spread 3.00% (4.25% PIK) Interest Rate 10.16% Maturity Date 7/7/20282022-12-310001655050us-gaap:EquitySecuritiesMember2022-01-012022-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberbcsf:HighTechIndustriesMember2023-12-310001655050Investment East BCC Coinvest II, LLC Acquisition Date 7/23/20192023-01-012023-12-310001655050Non-controlled/Non-Affiliated Investments High Tech Industries Superna Inc. First Lien Senior Secured Loan - Revolver Maturity Date 3/6/20282023-12-310001655050bcsf:MeriplexCommunicationsLtd.Memberbcsf:RevolverCommitmentMember2023-12-310001655050bcsf:ChemicalsPlasticsAndRubberMember2023-12-310001655050Consumer Goods: Non-Durable Solaray, LLC First Lien Senior Secured Loan SOFR Spread 5.75% Interest Rate 10.43% Maturity Date 9/9/2023bcsf:BainCapitalSeniorLoanProgramLlcMember2022-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Six Standard Chartered Settlement Date 01/17/20242023-01-012023-12-310001655050Non-controlled/Non-Affiliated Investments Construction & Building YLG Holdings, Inc. First Lien Senior Secured Loan - Delayed Draw LIBOR Spread 5.00% Interest Rate 9.21% Maturity Date 10/31/20252022-12-310001655050Non-controlled/Non-Affiliated Investments Services: Business iBanFirst First Lien Senior Secured Loan EURIBOR Spread 10.00% PIK Interest Rate 13.91% Maturity Date 7/13/2028 Two2023-12-310001655050bcsf:FirstLienSeniorSecuredLoanMemberbcsf:NonControlledAffiliatedEntityMemberbcsf:DirectTravelIncOneMember2021-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberAutomotive JHCC Holdings, LLC First Lien Senior Secured Loan LIBOR Spread 5.75% Interest Rate 10.48% Maturity Date 9/9/20252022-12-310001655050bcsf:RisksRelatingToCommonStockMember2023-01-012023-12-3100016550502020-01-012020-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberForward Foreign Currency Exchange Contracts Counterparty One Morgan Stanley Settlement Date 2/17/20232022-01-012022-12-310001655050bcsf:VentivHoldcoIncMemberbcsf:RevolverCommitmentMember2023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMember2021-02-090001655050Forward Foreign Currency Exchange Contracts Counterparty Morgan Stanley Settlement Date 03/25/20242023-01-012023-12-310001655050bcsf:FirstLienSeniorSecuredLoanMemberbcsf:NonControlledAffiliatedEntityMemberbcsf:DirectTravelIncOneMember2022-01-012022-12-310001655050us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberbcsf:EquitySecuritiesOneMemberus-gaap:MeasurementInputDiscountRateMembersrt:WeightedAverageMember2023-12-310001655050us-gaap:FairValueInputsLevel3Memberbcsf:ValuationTechniqueComparableCompanyMultipleMemberbcsf:FirstLienSeniorSecuredLoansThreeMember2022-12-310001655050bcsf:CPSGroupHoldingsIncMemberbcsf:RevolverCommitmentMember2022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberBritish Pound Services: Business Brook Bidco First Lien Senior Secured Loan SONIA Spread 7.37% PIK Interest Rate 12.56% Maturity Date 7/10/20282023-12-310001655050bcsf:SumitomoCreditFacilityMemberbcsf:BorrowingBaseEqualToOrGreaterThanProductOf1.60AndRevolvingCreditExposureMemberbcsf:RiskFreeRateMember2021-12-242021-12-240001655050Non-controlled/Non-Affiliated Investments Environmental Industries Titan Cloud Software, Inc First Lien Senior Secured Loan - Revolver Maturity Date 9/7/20282023-12-310001655050bcsf:VGlobalHoldingsLLCMemberbcsf:RevolverCommitmentMember2022-12-310001655050bcsf:ControlledAffiliatedEntityMemberbcsf:EquityInterestMemberbcsf:InternationalSeniorLoanProgramLlcMember2023-01-012023-12-310001655050Non-controlled/Non-Affiliated Investments FIRE: Insurance Margaux Acquisition Inc. First Lien Senior Secured Loan - Revolver SOFR Spread 5.90% Interest Rate 11.29% Maturity Date 12/19/20252023-12-310001655050Non-controlled/Non-Affiliated Investments Telecommunications Meriplex Communications, Ltd. First Lien Senior Secured Loan SOFR Spread 5.00% Interest Rate 9.42% Maturity Date 7/17/20282022-12-310001655050Non-controlled/Non-Affiliated Investments Telecommunications DC Blox Inc. First Lien Senior Secured Loan - Delayed Draw LIBOR Spread 2.00% (6.00% PIK) Interest Rate 11.74% Maturity Date 3/22/20262022-12-310001655050Non-controlled/Non-Affiliated Investments Aerospace & Defense Precision Ultimate Holdings, LLC Equity Interest2022-12-310001655050Non-controlled/Non-Affiliated Investments Media: Diversified & Production Aptus 1724 Gmbh First Lien Senior Secured Loan LIBOR Spread 6.25% Interest Rate 10.97% Maturity Date 2/23/20282022-12-310001655050bcsf:HighTechIndustriesMember2022-01-012022-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberHealthcare & Pharmaceuticals SunMed Group Holdings, LLC First Lien Senior Secured Loan SOFR Spread 5.60% Interest Rate 10.96% Maturity Date 6/16/20282023-12-3100016550502022-12-310001655050bcsf:BCSFAdvisorsLpMember2021-01-012021-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberbcsf:FireFinanceMembercurrency:GBP2023-12-310001655050srt:MinimumMember2023-01-012023-12-310001655050bcsf:McLarensAcquisitionIncMemberbcsf:DelayedDrawCommitmentMember2023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberEuropean Currency Media: Diversified & Production 9 Story Media Group Inc. First Lien Senior Secured Loan EURIBOR Spread 5.25% Interest Rate 9.21% Maturity Date 4/30/20262023-12-310001655050bcsf:HospitalityHoldingsMember2022-01-012022-12-310001655050Investment WSP LP Interest Acquisition Date 8/31/20212022-01-012022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberForward Foreign Currency Exchange Contracts Counterparty Three Morgan Stanley Settlement Date 2/17/20232022-01-012022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberBritish Pound Environmental Industries Reconomy First Lien Senior Secured Loan Delayed Draw SONIA Spread 6.25% Interest Rate 11.44% Maturity Date 6/25/20292023-12-310001655050us-gaap:InvestmentAffiliatedIssuerControlledMember2023-01-012023-12-310001655050us-gaap:InvestmentAffiliatedIssuerControlledMember2021-01-012021-12-310001655050us-gaap:InvestmentAffiliatedIssuerControlledMember2023-12-310001655050srt:MaximumMemberbcsf:MeasurementInputProbabilityWeightingOfAlternativeOutcomesMemberus-gaap:FairValueInputsLevel3Memberbcsf:FirstLienSeniorSecuredLoansThreeMember2022-12-310001655050us-gaap:SubordinatedDebtMember2023-01-012023-12-310001655050Non-controlled/Non-Affiliated Investments High Tech Industries Element Buyer, Inc. First Lien Senior Secured Loan SOFR Spread 6.00% Interest Rate 11.46% Maturity Date 7/19/20262023-12-310001655050Non-controlled/Non-Affiliated Investments Services: Business Parcel2Go Equity Interest2022-12-3100016550502021-01-012023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty One Bank of New York Mellon Settlement Date 6/10/20252023-01-012023-12-310001655050us-gaap:SubordinatedDebtMember2021-12-310001655050us-gaap:ValuationTechniqueDiscountedCashFlowMembersrt:MaximumMemberus-gaap:FairValueInputsLevel3Memberbcsf:EquitySecuritiesOneMemberus-gaap:MeasurementInputDiscountRateMember2022-12-310001655050Non-controlled/Non-Affiliated Investments Consumer Goods: Non-Durable WU Holdco, Inc. First Lien Senior Secured Loan - Revolver SOFR Spread 5.65% Interest Rate 11.00% Maturity Date 3/26/20252023-12-310001655050Non-controlled/Non-Affiliated Investments Services: Business Elevator Holdco Inc. Equity Interest2022-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty One Morgan Stanley Settlement Date 3/27/2023bcsf:InternationalSeniorLoanProgramLlcMember2022-12-310001655050bcsf:SumitomoCreditFacilityMember2023-01-012023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberForward Foreign Currency Exchange Contracts Counterparty Three Standard Chartered Settlement Date 1/18/20232022-01-012022-12-310001655050bcsf:InterestRateFloorFourMember2023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberbcsf:ClassENotesTwoZeroTwoThreeOneNotesMember2023-01-012023-12-310001655050bcsf:FireFinanceSectorMember2023-12-310001655050Investment Ventiv Topco, Inc. Acquisition Date 9/3/20192023-01-012023-12-310001655050bcsf:BCSFAdvisorsLpMemberbcsf:PreIncentiveFeeNetInvestmentIncomeExceedsCatchUpAmountMember2023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberRetail Thrasio, LLC First Lien Senior Secured Loan SOFR Spread 9.26% Interest Rate 14.61% Maturity Date 12/18/20262023-12-310001655050bcsf:InternationalSeniorLoanProgramLLCMember2023-12-140001655050bcsf:IncentiveFeeBasedOnIncomeMember2021-01-012021-12-310001655050bcsf:TwentyTwentyThreeNotesMember2021-12-310001655050Investment NPC International, Inc. Acquisition Date 4/1/20212023-01-012023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberbcsf:ClassENotesTwoZeroTwoThreeOneNotesMember2023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Bank of New York Mellon Settlement Date 7/28/20252023-01-012023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberEuropean Currency Chemicals, Plastics, & Rubber V Global Holdings LLC First Lien Senior Secured Loan EURIBOR Spread 5.75% Interest Rate 8.04% Maturity Date 12/22/20272022-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberHigh Tech Industries AMI US Holdings Inc. First Lien Senior Secured Loan SOFR Spread 5.25% Interest Rate 10.71% Maturity Date 4/1/2025 One2023-12-310001655050bcsf:NineStoryMediaGroupIncMemberbcsf:RevolverCommitmentMember2023-12-310001655050bcsf:PreferredStockOneMemberus-gaap:MeasurementInputEbitdaMultipleMemberus-gaap:FairValueInputsLevel3Memberbcsf:ValuationTechniqueComparableCompanyMultipleMember2023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Bank of New York Mellon Settlement Date 1/24/20242023-01-012023-12-310001655050country:US2023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Bank of New York Mellon Settlement Date 3/16/20232022-01-012022-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberHigh Tech Industries Applitools First Lien Senior Secured Loan SOFR Spread 6.25% Interest Rate 11.61% Maturity Date 5/25/20292023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberbcsf:ConsumerNonDurableMember2022-12-310001655050bcsf:WSPRevolvingLoanMemberbcsf:RevolverCommitmentMember2022-12-310001655050Non-controlled/Non-Affiliated Investments Automotive Gills Point S First Lien Senior Secured Loan – Revolver Maturity Date 5/17/20292023-12-310001655050bcsf:SumitomoCreditFacilityMemberus-gaap:EurodollarMemberbcsf:BorrowingBaseLessThanProductOf1.60AndRevolvingCreditExposureMember2021-12-242021-12-240001655050bcsf:InternationalSeniorLoanProgramLlcMemberEuropean Currency Services: Business iBanFirst First Lien Senior Secured Loan Spread 10.00% PIK Interest Rate 10.00% Maturity Date 7/13/20282022-12-310001655050us-gaap:ValuationTechniqueDiscountedCashFlowMembersrt:MaximumMemberus-gaap:FairValueInputsLevel3Memberbcsf:EquitySecuritiesOneMemberus-gaap:MeasurementInputDiscountRateMember2023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberbcsf:InvestmentsOperationsMemberbcsf:LargestInvesteeMemberbcsf:InvestmentConcentrationRiskMember2022-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberbcsf:ClassaOneaTwoZeroOneEightOneNotesMember2023-12-310001655050bcsf:NonControlledAffiliatedEntityMemberbcsf:FirstLienSeniorSecuredLoanRevolverMemberbcsf:WalkerEdisonFirstFurnitureCompanyLlcMember2023-01-012023-12-310001655050bcsf:NonControlledAffiliatedEntityMemberbcsf:EquityInterestMemberbcsf:DirectTravelIncMember2022-12-310001655050us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberbcsf:SecondLienSeniorSecuredLoanMemberus-gaap:MeasurementInputComparabilityAdjustmentMember2022-12-310001655050Investment Eagle Rock Capital Corporation Acquisition Date 7/23/20192022-01-012022-12-310001655050Non-controlled/Non-Affiliated Investments Media: Broadcasting & Subscription Lightning Finco Limited First Lien Senior Secured Loan EURIBOR Spread 5.50% Interest Rate 9.39% Maturity Date 8/31/20282023-12-310001655050Non-controlled/Non-Affiliated Investments Aerospace & Defense Kellstrom Aerospace Group, Inc Equity Interest 2023-12-310001655050bcsf:NonControlledAffiliatedEntityMemberbcsf:FirstLienSeniorSecuredLoanDelayedDrawMemberbcsf:DirectTravelIncTwoMember2022-01-012022-12-310001655050bcsf:InterestRateFloorSixMember2022-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberConsumer Goods: Durable TLC Purchaser, Inc. First Lien Senior Secured Loan SOFR Spread 2.26% (6.25% PIK) Interest Rate 14.15% Maturity Date 10/13/20252023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberHigh Tech Industriess AMI US Holdings Inc First Lien Senior Secured Loan LIBOR Spread 5.25% Interest Rate 9.63% Maturity Date 4/1/20252022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberEuropean Currency Healthcare & Pharmaceuticals Pharmathen First Lien Senior Secured Loan- Revolver EURIBOR Spread 5.73% Interest Rate 9.62% Maturity Date 10/25/20282023-12-310001655050Non-controlled/Non-Affiliated Investments Aerospace & Defense GSP Holdings, LLC First Lien Senior Secured Loan LIBOR Spread 5.75% (0.25%PIK) Interest Rate 10.48% Maturity Date 11/6/20252022-12-310001655050Non-controlled/Non-Affiliated Investments Transportation: Cargo ARL Holdings, LLC Equity Interest One2022-12-310001655050Non-controlled/Non-Affiliate Investments Healthcare & Pharmaceuticals Mertus 522. GmbH First Lien Senior Secured Loan EURIBOR Spread 6.25% Interest Rate 8.11% Maturity Date 5/28/20262022-12-310001655050Investment BCC Jetstream Holdings Aviation (Off I), LLC Acquisition Date 6/1/20172022-01-012022-12-310001655050Non-controlled/Non-Affiliated Investments Hotel, Gaming & Leisure Aimbridge Acquisition Co., Inc. Second Lien Senior Secured Loan LIBOR Spread 7.50% Interest Rate 11.62% Maturity Date 2/1/20272022-12-310001655050us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberbcsf:FirstLienSeniorSecuredLoansOneMemberus-gaap:MeasurementInputComparabilityAdjustmentMember2022-12-310001655050bcsf:RevolvingAdvisorLoanMember2022-01-012022-12-310001655050Non-controlled/Non-Affiliated Investments Services: Business Refine Intermediate, Inc. First Lien Senior Secured Loan SOFR Spread 4.60% Interest Rate 9.95% Maturity Date 3/3/20272023-12-310001655050Non-controlled/Non-Affiliated Investments Transportation: Cargo A&R Logistics, Inc. First Lien Senior Secured Loan - Revolver SOFR Spread 6.00% Interest Rate 11.45% Maturity Date 5/5/20252023-12-310001655050bcsf:TotalSeniorSecuritiesMember2019-12-310001655050srt:MaximumMember2020-07-022020-07-020001655050Non-controlled/Non-Affiliated Investments Construction & Building Regan Development Holdings Limited First Lien Senior Secured Loan EURIBOR Spread 6.50% Interest Rate 8.29% Maturity Date 4/18/2023 One2022-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Seven Standard Chartered 07/18/20242023-01-012023-12-310001655050Consumer Goods: Non-Durable RoC Opco LLC First Lien Senior Secured Loan LIBOR Spread 8.00% Interest Rate 12.73% Maturity Date 2/25/2025bcsf:BainCapitalSeniorLoanProgramLlcMember2022-12-310001655050bcsf:MeasurementInputProbabilityWeightingOfAlternativeOutcomesMemberus-gaap:FairValueInputsLevel3Memberbcsf:FirstLienSeniorSecuredLoansThreeMembersrt:MinimumMember2023-12-310001655050bcsf:ResetNotes2019OneCLOMember2023-01-012023-12-310001655050bcsf:EnvironmentalIndustriesSectorMember2023-12-310001655050us-gaap:MeasurementInputEbitdaMultipleMembersrt:MaximumMemberus-gaap:FairValueInputsLevel3Memberbcsf:ValuationTechniqueComparableCompanyMultipleMemberbcsf:EquitySecuritiesTwoMember2023-12-310001655050Non-controlled/Non-Affiliated Investments Transportation: Cargo A&R Logistics, Inc. 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Acquisition Date 2/22/20212023-01-012023-12-310001655050bcsf:IntoxalockMemberbcsf:RevolverCommitmentMember2023-12-310001655050Non-controlled/Non-Affiliated Investments Services: Business Caribou Bidco Limited First Lien Senior Secured Loan SONIA Spread 6.00% Interest Rate 7.19% Maturity Date 1/29/20292022-12-310001655050Non-controlled/Non-Affiliate Investments High Tech Industries Cloud Technology Solutions (CTS) First Lien Senior Secured Loan SONIA Spread 7.50% Interest Rate 11.93% Maturity Date 1/3/20302022-12-310001655050Non-controlled/Non-Affiliated Investments Construction & Building Service Master First Lien Senior Secured Loan SOFR Spread 6.11% (1.00% PIK) Interest Rate 12.47% Maturity Date 8/16/20272023-12-310001655050Non-controlled/Non-Affiliated Investments Environmental Industries Reconomy First Lien Senior Secured Loan SONIA Spread 6.25% Interest Rate 11.44% Maturity Date 6/25/20292023-12-310001655050Non-controlled/Non-Affiliated Investments Aerospace & Defense Precision Ultimate Holdings, LLC Equity Interest 2023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberAustralian Dollar Aerospace & Defense Ansett Aviation Training Equity Interest2023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberAerospace & Defense Whitcraft LLC First Lien Senior Secured Loan SOFR Spread 7.00% Interest Rate 11.73% Maturity Date 4/3/20232022-12-310001655050us-gaap:EquitySecuritiesMember2023-01-012023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberCanadian Dollar Retail New Look Vision Group First Lien Senior Secured Loan - Delayed Draw CDOR Spread 5.50% Interest Rate 10.38% Maturity Date 5/26/2028 One2022-12-310001655050bcsf:FirstLienSeniorSecuredLoansFourMemberus-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputDiscountRateMember2022-12-310001655050Non-controlled/Non-Affiliated Investments High Tech Industries Ventiv Holdco, Inc. 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First Lien Senior Secured Loan - Revolver SOFR Spread 6.25% Interest Rate 10.74% Maturity Date 3/10/20282022-12-310001655050Investment ADT Pizza, LLC Acquisition Date 10/29/20182022-01-012022-12-310001655050Non-controlled/Non-Affiliated Investments Aerospace & Defense Forming Machining Industries Holdings, LLC First Lien Senior Secured Loan SOFR Spread 4.40% Interest Rate 9.79% Maturity Date 10/9/20252023-12-310001655050REP Coinvest III- A Omni, LP Equity Interest2023-01-012023-06-300001655050Energy: Oil & Gas Amspec Services, Inc First Lien Senior Secured Loan LIBOR Spread 5.75% Interest Rate 10.48% Maturity Date 7/2/2024bcsf:BainCapitalSeniorLoanProgramLlcMember2022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberbcsf:FireFinanceMembercurrency:GBP2022-12-310001655050bcsf:ServicesConsumerMember2022-12-310001655050bcsf:FirstLienSeniorSecuredLoansFourMemberus-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputDiscountRateMembersrt:WeightedAverageMember2022-12-310001655050bcsf:NonControlledAffiliatedEntityMemberbcsf:EquityInterestMemberbcsf:DirectTravelIncMember2023-01-012023-12-310001655050Non-controlled/Non-Affiliated Investments Services: Business ACAMS Equity Interest2022-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberbcsf:ConsumerDurableMember2022-12-310001655050bcsf:OghBidcoLimitedMemberbcsf:DelayedDrawCommitmentMember2023-12-310001655050Non-controlled/Non-Affiliated Investments Hotel, Gaming & Leisure Concert Golf Partners Holdco LLC First Lien Senior Secured Loan - Delayed Draw SOFR Spread 5.50% Interest Rate 11.25% Maturity Date 4/2/20292023-12-310001655050bcsf:DelayedDrawCommitmentMemberbcsf:TGISportBidcoPtyLtdMember2022-12-310001655050Investment Service Master Acquisition Date 8/16/20212023-01-012023-12-310001655050bcsf:Notes2018OneMember2023-01-012023-12-310001655050bcsf:InvestmentHoldingsAndCashEquivalentsMember2023-12-310001655050Controlled Affiliate Investments Investment Vehicles International Senior Loan Program, LLC Equity Interest Investment Vehicles2023-12-310001655050bcsf:BankingFinanceInsuranceAndRealEstateMember2023-01-012023-12-310001655050bcsf:ContainersPackagingAndGlassMember2023-01-012023-12-310001655050Non-controlled/Non-Affiliated Investments Transportation: Cargo REP Coinvest III- A Omni, L.P. 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First Lien Senior Secured Loan LIBOR Spread 5.75% Interest Rate 10.48% Maturity Date 12/23/20262022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMembercurrency:CADbcsf:MediaDiversifiedAndProductionMember2022-12-310001655050bcsf:CBNikeIntermediateCoLtdMemberbcsf:RevolverCommitmentMember2022-12-310001655050bcsf:ServicesBusinessMember2023-01-012023-12-310001655050Investment BCC Jetstream Holdings Aviation (On II), LLC Acquisition Date 6/1/20172023-01-012023-12-310001655050bcsf:HealthdriveMemberbcsf:DelayedDrawCommitmentMember2023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberTransportation: Cargo Omni Intermediate First Lien Senior Secured Loan SOFR Spread 5.15% Interest Rate 10.54% Maturity Date 11/23/20262023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Standard Chartered Settlement Date 06/18/20242023-01-012023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberbcsf:InvestmentsOperationsMemberbcsf:InvestmentConcentrationRiskMemberbcsf:FiveLargestInvesteeMember2022-12-310001655050Non-controlled/Non-Affiliated Investments High Tech Industries Continued Superna Inc. 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First Lien Senior Secured Loan SOFR Spread 5.50% Interest Rate 10.18% Maturity Date 9/3/20252022-12-310001655050bcsf:FireFinanceSectorMember2022-01-012022-12-310001655050bcsf:Class2RSeniorSecuredFloatingRateNotesMember2023-12-310001655050bcsf:EnergyOilAndGasMember2022-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberBanking, Finance, Insurance & Real Estate Morrow Sodali Global LLC First Lien Senior Secured Loan SOFR Spread 5.00% Interest Rate 9.21% Maturity Date 4/25/20282022-12-310001655050Non-controlled/Non-Affiliated Investments Retail New Look Vision Group First Lien Senior Secured Loan - Revolver Maturity Date 5/26/20262023-12-310001655050Non-controlled/Non-Affiliated Investments Consumer Goods: Durable Tangent Technologies Acquisition, LLC Second Lien Senior Secured Loan SOFR Spread 9.00% Interest Rate 14.44% Maturity Date 5/30/20282023-12-310001655050country:SE2022-12-310001655050Investment Eagle Rock Capital Corporation Acquisition Date 12/9/20212023-01-012023-12-310001655050British Pound Services: Business Learning Pool First Lien Senior Secured Loan SOFR Spread 7.51% PIK Interest Rate 12.81% Maturity Date 7/7/2028bcsf:InternationalSeniorLoanProgramLlcMember2023-12-310001655050Non-controlled/Non-Affiliated Investments Wholesale SureWerx First Lien Senior Secured Loan - Delayed Draw Maturity Date 12/28/20292023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberRetail New Look (Delaware) Corporation First Lien Senior Secured Loan SOFR Spread 5.65% Interest Rate 11.00% Maturity Date 5/26/20282023-12-310001655050Investment Gills Point S Acquisition Date 5/17/20232023-01-012023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberbcsf:ClassBTwoZeroOneEightOneNotesMember2023-01-012023-12-310001655050bcsf:FirstLienSeniorSecuredLoanMemberbcsf:ControlledAffiliatedEntityMemberbcsf:BccJetstreamHoldingsAviationOnIiLlcMember2023-01-012023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberHigh Tech Industries Ventiv Holdco, Inc. First Lien Senior Secured Loan SOFR Spread 5.50% Interest Rate 10.18% Maturity Date 9/3/20252022-12-3100016550502022-04-012022-06-300001655050us-gaap:ConstructionSectorMember2022-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberus-gaap:AutomotiveSectorMember2023-12-310001655050Non-controlled/Non-Affiliated Investments Capital Equipment TCFIII Owl Finance, LLC Subordinated Debt Spread 12.00% PIK Interest Rate 12.00% Maturity Date 1/30/20272023-12-310001655050Non-controlled/Non-Affiliated Investments Media: Diversified & Production Efficient Collaborative Retail Marketing Company, LLC First Lien Senior Secured Loan SOFR Spread 7.50% (1.50% PIK) Interest Rate 14.45% Maturity Date 12/31/2025 One2023-12-310001655050Non-controlled/Non-Affiliated Investments Transportation: Cargo REP Coinvest III- A Omni, L.P. 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First Lien Senior Secured Loan - Delayed Draw SOFR Spread 5.90% Interest Rate 11.29% Maturity Date 12/19/20242023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberus-gaap:SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember2023-06-300001655050Controlled Affiliate Investments Investment Vehicles Bain Capital Senior Loan Program, LLC Subordinated Note Investment Vehicles Spread 10.00% Interest Rate 10.00% Maturity Date 12/27/20332023-12-310001655050us-gaap:WarrantMember2021-12-3100016550502021-01-012021-03-310001655050Non-controlled/Non-Affiliate Investments Environmental Industries Reconomy First Lien Senior Secured Loan EURIBOR Spread 6.00% Interest Rate 8.20% Maturity Date 6/24/20292022-12-310001655050bcsf:TotalSeniorSecuritiesMember2018-12-310001655050Opus2 Equity Interest2023-01-012023-06-300001655050bcsf:InternationalSeniorLoanProgramLlcMemberDanish Krone High Tech Industries VPARK BIDCO AB First Lien Senior Secured Loan CIBOR Spread 4.00% Interest Rate 7.87% Maturity Date 3/10/20252023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Bank of New York Mellon Settlement Date 12/13/20242023-01-012023-12-310001655050Non-controlled/Non-Affiliated Investments Media: Advertising, Printing & Publishing Ansira Holdings, Inc. First Lien Senior Secured Loan LIBOR Spread 6.50% Interest Rate 10.91% Maturity Date 12/20/20242022-12-310001655050bcsf:FirstLienSeniorSecuredLoanMemberbcsf:NonControlledAffiliatedEntityMemberbcsf:DirectTravelIncTwoMember2022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberbcsf:HealthcareAndPharmaceuticalsMembercurrency:AUD2022-12-310001655050Non-controlled/Non-Affiliated Investments Wholesale Abracon Group Holding, LLC. First Lien Senior Secured Loan - Delayed Draw Maturity Date 7/6/20282022-12-310001655050Non-controlled/Non-Affiliate Investments FIRE: Insurance Margaux Acquisition Inc. First Lien Senior Secured Loan - Delayed Draw LIBOR Spread 5.75 % Interest Rate 9.49% Maturity Date 12/19/20242022-12-310001655050Non-controlled/Non-Affiliated Investments Chemicals, Plastics & Rubber AP Plastics Group, LLC First Lien Senior Secured Loan SOFR Spread 4.75% Interest Rate 10.19% Maturity Date 8/10/20282023-12-310001655050Non-controlled/Non-Affiliate Investments High Tech Industries Gluware Warrants2022-12-310001655050bcsf:TransportationConsumerMember2023-01-012023-12-310001655050 Non-controlled/Non-Affiliated Investments Consumer Goods: Durable Stanton Carpet Second Lien Senior Secured Loan SOFR Spread 9.15% Interest Rate 14.56% Maturity Date 3/31/20282023-12-310001655050bcsf:VGlobalHoldingsLLCMemberbcsf:RevolverCommitmentMember2023-12-310001655050Non-controlled/Non-Affiliated Investments Consumer Goods: Durable TLC Purchaser, Inc. 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First Lien Senior Secured Loan SOFR Spread 6.50% Interest Rate 11.98% Maturity Date 5/5/20252023-12-310001655050us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberbcsf:PreferredEquityInterestInInvestmentVehiclesMember2022-12-310001655050bcsf:MargauxUKFinanceLimitedMemberbcsf:RevolverCommitmentMember2023-12-310001655050srt:MaximumMemberbcsf:MeasurementInputProbabilityWeightingOfAlternativeOutcomesMemberus-gaap:FairValueInputsLevel3Memberbcsf:EquitySecuritiesThreeMember2022-12-310001655050Non-controlled/Non-Affiliated Investments Healthcare & Pharmaceuticals Mertus 522. GmbH First Lien Senior Secured Loan EURIBOR Spread 6.25% (0.75% PIK) Interest Rate 11.03% Maturity Date 5/28/20262023-12-310001655050bcsf:OctoberTwoThousandTwentySixNotesMember2022-12-310001655050us-gaap:InvestmentUnaffiliatedIssuerMember2022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberForward Foreign Currency Exchange Contracts Counterparty One Morgan Stanley Settlement 1/18/20232022-12-310001655050bcsf:IncentiveFeeBasedOnIncomeAfterWaiverMember2023-01-012023-12-310001655050currency:EURbcsf:InternationalSeniorLoanProgramLlcMemberbcsf:ServicesBusinessMember2023-12-310001655050Non-controlled/Non-Affiliated Investments Construction & Building Chase Industries, Inc. First Lien Senior Secured Loan - Delayed Draw SOFR Spread 5.65% (1.50% PIK) Interest Rate 12.50% Maturity Date 5/12/20252023-12-3100016550502021-04-012021-06-300001655050Non-controlled/Affiliated Investments Transportation: Consumer Direct Travel, Inc. 1 First Lien Senior Secured Loan SOFR Spread 6.65% Interest Rate 12.00% Maturity Date 10/2/20252023-12-310001655050bcsf:BccMiddleMarketClo2019LlcMemberbcsf:Notes2019OneMemberus-gaap:SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember2023-06-152023-06-150001655050bcsf:InternationalSeniorLoanProgramLlcMember2021-02-092021-02-090001655050Forward Foreign Currency Exchange Contracts Counterparty Two Morgan Stanley Settlement Date 01/17/20242023-12-3100016550502019-02-020001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberbcsf:InterestRateFloorThreeMember2022-12-310001655050bcsf:YLGHoldingsIncMemberbcsf:RevolverCommitmentMember2023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberbcsf:FireFinanceMember2023-12-310001655050Non-controlled/Non-Affiliate Investments High Tech Industries Element Buyer, Inc. First Lien Senior Secured Loan LIBOR Spread 5.50% Interest Rate 9.89% Maturity Date 7/18/20252022-12-310001655050Investment ARL Holdings, LLC Acquisition Date 5/3/20192022-01-012022-12-310001655050 Investment DC Blox Inc. 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First Lien Senior Secured Loan LIBOR Spread 5.75% Interest Rate 10.48% Maturity Date 7/2/2024 One2022-12-310001655050bcsf:InterestRateFloorFourMemberbcsf:InternationalSeniorLoanProgramLlcMember2023-12-310001655050bcsf:ApolloIntelligenceMemberbcsf:RevolverCommitmentMember2022-12-310001655050Non-controlled/Non-Affiliated Investments High Tech Industries Continued VPARK BIDCO AB First Lien Senior Secured Loan CIBOR Spread 4.00% Interest Rate 6.03% Maturity Date 3/10/20252022-12-310001655050bcsf:Class2RSeniorSecuredFloatingRateNotesMember2021-11-300001655050bcsf:Notes2.55PercentDueOctober2026Member2023-01-012023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Bank of New York Mellon Settlement Date 7/28/20252022-01-012022-12-310001655050bcsf:NonControlledAffiliatedEntityMemberbcsf:EquityInterestMemberbcsf:WalkerEdisonFirstFurnitureCompanyLlcMember2023-12-310001655050bcsf:SurewerxMemberbcsf:RevolverCommitmentMember2023-12-310001655050bcsf:JPMCreditFacilityMemberbcsf:LiborMember2019-04-302019-04-300001655050Forward Foreign Currency Exchange Contracts Counterparty Bank of New York Mellon Settlement Date 7/26/20232022-12-310001655050Healthcare & Pharmaceuticals HealthDrive First Lien Senior Secured Loan SOFR Spread 6.10% Interest Rate 11.46% Maturity Date 8/20/2029bcsf:BainCapitalSeniorLoanProgramLlcMember2023-12-310001655050us-gaap:RetailSectorMember2022-01-012022-12-310001655050bcsf:FirstLienSeniorSecuredLoanMemberbcsf:ControlledAffiliatedEntityMemberbcsf:BccJetstreamHoldingsAviationOnIiLlcMember2022-12-310001655050bcsf:Notes2.95PercentDueMarch2026Member2021-03-100001655050Non-controlled/Non-Affiliated Investments Consumer Goods: Non-Durable RoC Opco LLC First Lien Senior Secured Loan SOFR Spread 7.60% Interest Rate 12.95% Maturity Date 2/25/20252023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Bank of New York Mellon Settlement Date 11/15/20232022-12-310001655050Controlled Affiliate Investments Aerospace & Defense Gale Aviation (Offshore) Co Equity Interest2023-12-310001655050Non-controlled/Non-Affiliate Investments High Tech Industries Element Buyer, Inc. 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GmbH First Lien Senior Secured Loan EURIBOR Spread 6.25% Interest Rate 8.69% Maturity Date 5/28/20262022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberbcsf:PantheonMember2023-12-140001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberbcsf:HotelGamingAndLeisureMember2023-12-310001655050bcsf:InterestRateFloorSixMember2023-12-310001655050Non-controlled/Non-Affiliated Investments Wholesale Abracon Group Holding, LLC. First Lien Senior Secured Loan - Revolver SOFR Spread 6.00% Interest Rate 11.57% Maturity Date 7/6/20282023-12-310001655050Investment TLC Holdco LP Acquisition Date 10/11/20192022-01-012022-12-310001655050bcsf:ControlledAffiliatedEntityMemberbcsf:EquityInterestMemberbcsf:BainCapitalSeniorLoanProgramLlcMember2023-01-012023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberForward Foreign Currency Exchange Contracts Counterparty Standard Chartered Settlement Date 6/14/20232022-01-012022-12-310001655050bcsf:SunmedGroupHoldingsLLCMemberbcsf:RevolverCommitmentMember2023-12-310001655050us-gaap:RetailMember2022-12-310001655050Investment Darcy Partners Acquisition Date 6/1/20222022-01-012022-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberbcsf:BankingFinanceInsuranceAndRealEstateSectorMember2022-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberbcsf:ClassaOneBTwoZeroOneEightOneNotesMember2023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Morgan Stanley Settlement Date 02/14/20242023-12-310001655050bcsf:RevolverCommitmentMemberbcsf:PaisleyBidcoLimitedMember2022-12-310001655050Non-controlled/Non-Affiliated Investments Chemicals, Plastics & Rubber AP Plastics Group, LLC First Lien Senior Secured Loan LIBOR Spread 4.75% Interest Rate 8.97% Maturity Date 8/10/20282022-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberHigh Tech Industries Drilling Info Holdings, Inc First Lien Senior Secured Loan LIBOR Spread 4.25% Interest Rate 8.63% Maturity Date 7/30/20252022-12-310001655050Telecommunications Conterra Ultra Broadband Holdings, Inc First Lien Senior Secured Loan SOFR Spread 4.75% Interest Rate 9.18% Maturity Date 4/27/2027bcsf:BainCapitalSeniorLoanProgramLlcMember2022-12-310001655050bcsf:Notes2019OneMember2021-11-302021-11-300001655050bcsf:OghBidcoLimitedMemberbcsf:DelayedDrawCommitmentMember2022-12-310001655050bcsf:TransportationConsumerMember2023-12-310001655050bcsf:NonControlledAffiliatedEntityMemberbcsf:EquityInterestMemberbcsf:AdtPizzaLlcMember2022-01-012022-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberbcsf:ClassCTwoZeroOneEightOneNotesMember2023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberAerospace & Defense Saturn Purchaser Corp. First Lien Senior Secured Loan SOFR Spread 5.60% Interest Rate 11.01% Maturity Date 7/23/20292023-12-310001655050Non-controlled/Non-Affiliated Investments Media: Diversified & Production International Entertainment Investments Limited First Lien Senior Secured Loan SONIA Spread 4.75% Interest Rate 7.71% Maturity Date 11/30/20252022-12-310001655050Non-controlled/Non-Affiliated Investments High Tech Industries Continued Utimaco Preferred Equity2022-12-310001655050Non-controlled/Non-Affiliated Investments Media: Advertising, Printing & Publishing Ansira Holdings, Inc. First Lien Senior Secured Loan - Delayed Draw Maturity Date 12/20/20242022-12-310001655050Non-controlled/Non-Affiliate Investments High Tech Industries AQ Software Corporation Preferred Equity2022-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty One Morgan Stanley Settlement Date 01/17/2024 2023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberContainers, Packaging & Glas Iris Holding, Inc First Lien Senior Secured Loan SOFR Spread 4.75% Interest Rate 8.94% Maturity Date 6/28/20282022-12-310001655050us-gaap:LetterOfCreditMemberbcsf:GaleAviationOffshoreCoMember2022-01-260001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberHotel, Gaming & Leisure Aimbridge Acquisition Co., Inc. Second Lien Senior Secured Loan SOFR Spread 7.50% Interest Rate 12.97% Maturity Date 2/1/20272023-12-310001655050us-gaap:FairValueInputsLevel3Member2022-12-310001655050Non-controlled/Non-Affiliated Investments Services: Business Learning Pool First Lien Senior Secured Loan SOFR Spread 7.51% PIK Interest Rate 12.81% Maturity Date 7/7/20282023-12-310001655050bcsf:Classa1rSeniorSecuredFloatingRateNotesMember2023-01-012023-12-310001655050bcsf:BankingFinanceInsuranceAndRealEstateMember2022-01-012022-12-310001655050us-gaap:PreferredStockMember2022-12-310001655050Automotive JHCC Holdings, LLC First Lien Senior Secured Loan SOFR Spread 5.25% Interest Rate 10.75% Maturity Date 9/9/2025bcsf:BainCapitalSeniorLoanProgramLlcMember2023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberbcsf:ServicesConsumerMember2022-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Three Standard Chartered Settlement Date 01/17/20242023-01-012023-12-310001655050bcsf:NonControlledAffiliatedEntityMemberbcsf:EquityInterestMemberbcsf:AnsettAviationTrainingMember2022-01-012022-12-3100016550502023-03-310001655050bcsf:Parcel2GoMemberbcsf:DelayedDrawCommitmentMember2023-12-310001655050Non-controlled/Non-Affiliated Investments Hotel, Gaming & Leisure Pyramid Global Hospitality First Lien Senior Secured Loan - Revolver Maturity Date 1/19/20272023-12-310001655050bcsf:MediaPublishingMember2022-12-310001655050bcsf:SecondLienSeniorSecuredLoansMember2023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberbcsf:MediaDiversifiedAndProductionMembercurrency:GBP2023-12-310001655050Non-controlled/Non-Affiliated Investments Retail New Look Vision Group First Lien Senior Secured Loan - Delayed Draw CDOR Spread 5.50% Interest Rate 10.93% Maturity Date 5/26/20282023-12-310001655050bcsf:JPMCreditFacilityMembersrt:MinimumMember2019-04-300001655050us-gaap:ForeignExchangeForwardMemberbcsf:CitibankMember2023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberHigh Tech Industries Ventiv Holdco, Inc. First Lien Senior Secured Loan SOFR Spread 5.60% (1.00% PIK) Interest Rate 11.95% Maturity Date 9/3/20252023-12-310001655050Automotive Intoxalock First Lien Senior Secured Loan SOFR Spread 6.50% Interest Rate 11.96% Maturity Date 11/1/2028bcsf:BainCapitalSeniorLoanProgramLlcMember2023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberRetail Thrasio First Lien Senior Secured Loan LIBOR Spread 7.00% Interest Rate 11.17% Maturity Date 12/18/20262022-12-310001655050Non-controlled/Non-Affiliated Investments Services: Business Darcy Partners First Lien Senior Secured Loan SOFR Spread 7.75% Interest Rate 12.44% Maturity Date 6/1/20282022-12-310001655050bcsf:BeverageFoodandTobaccoSectorMember2023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty One Citibank Settlement Date 1/9/20232022-12-310001655050srt:MaximumMemberbcsf:MeasurementInputProbabilityWeightingOfAlternativeOutcomesMemberus-gaap:FairValueInputsLevel3Memberbcsf:EquitySecuritiesThreeMember2023-12-310001655050Non-controlled/Non-Affiliated Investments Services: Business masLabor First Lien Senior Secured Loan - Revolver Prime Rate Spread 6.50% Interest Rate 13.50% Maturity Date 7/1/20272022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberEuropean Currency FIRE: Insurance MRHT First Lien Senior Secured Loan EURIBOR Spread 6.75% Interest Rate 10.72% Maturity Date 2/1/20292023-12-310001655050us-gaap:DomesticCountryMember2021-01-012021-12-310001655050bcsf:RevolvingAdvisorLoanMember2022-12-310001655050Non-controlled/Non-Affiliated Investments Construction & Building YLG Holdings, Inc. First Lien Senior Secured Loan LIBOR Spread 5.00% Interest Rate 9.93% Maturity Date 10/31/20252022-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberServices: Business Smartronix First Lien Senior Secured Loan SOFR Spread 5.85% Interest Rate 11.57% Maturity Date 11/23/20282023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Bank of New York Mellon Settlement Date 8/15/20232022-01-012022-12-310001655050srt:MinimumMember2020-01-012020-03-310001655050bcsf:Notes8.50PercentDue2023Member2021-01-012021-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Citibank Settlement Date 1/9/20252023-01-012023-12-310001655050us-gaap:MeasurementInputEbitdaMultipleMemberus-gaap:FairValueInputsLevel3Memberbcsf:ValuationTechniqueComparableCompanyMultipleMemberbcsf:FirstLienSeniorSecuredLoansTwoMembersrt:WeightedAverageMember2022-12-310001655050bcsf:FederalIncomeTaxAndOtherTaxRisksMember2023-01-012023-12-310001655050us-gaap:WarrantMember2022-01-012022-12-310001655050bcsf:ConsumerGoodsWholesaleSectorMember2022-01-012022-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberConsumer Goods: Non-Durable WU Holdco, Inc. First Lien Senior Secured Loan SOFR Spread 5.65% Interest Rate 11.00% Maturity Date 3/26/2026 One2023-12-310001655050Non-controlled/Non-Affiliated Investments FIRE: Finance TA/Weg Holdings First Lien Senior Secured Loan - Delayed Draw SOFR Spread 5.85% Interest Rate 11.23% Maturity Date 10/4/20272023-12-310001655050Non-controlled/Non-Affiliated Investments High Tech Industries VPARK BIDCO AB First Lien Senior Secured Loan CIBOR Spread 4.00% Interest Rate 7.87% Maturity Date 03/10/20252023-12-310001655050country:AU2022-01-012022-12-310001655050us-gaap:SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMemberbcsf:BainCapitalSeniorLoanProgramLlcMemberbcsf:MM233CreditFacilityMember2023-09-272023-09-270001655050Non-controlled/Non-Affiliated Investments Services: Business Opus2 First Lien Senior Secured Loan SONIA Spread 5.03% Interest Rate 10.22% Maturity Date 5/5/20282023-12-310001655050Non-controlled/Non-Affiliate Investments High Tech Industries AMI US Holdings Inc. First Lien Senior Secured Loan LIBOR Spread 5.25% Interest Rate 9.63% Maturity Date 4/1/20252022-12-310001655050Non-controlled/Non-Affiliated Investments Retail Walker Edison First Lien Senior Secured Loan LIBOR Spread 5.75% (3.00% PIK) Interest Rate 13.48% Maturity Date 8/5/20272022-12-310001655050bcsf:EnvironmentalIndustriesSectorMember2022-01-012022-12-310001655050country:CA2022-12-310001655050bcsf:InterestRateFloorFourMemberbcsf:BainCapitalSeniorLoanProgramLlcMember2022-12-310001655050bcsf:WhitcraftParadigmMemberbcsf:RevolverCommitmentMember2023-12-310001655050Non-controlled/Non-Affiliated Investments Transportation: Cargo Gulf Winds International First Lien Senior Secured Loan - Revolver Maturity Date 12/16/20282022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberus-gaap:LineOfCreditMember2023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty One Standard Chartered Settlement Date 01/17/20242023-12-310001655050Non-controlled/Non-Affiliated Investments High Tech Industries Eleven Software First Lien Senior Secured Loan - Revolver SOFR Spread 8.10% Interest Rate 13.46% Maturity Date 9/25/20262023-12-310001655050Non-controlled/Non-Affiliated Investments Media: Advertising, Printing & Publishing Kpler First Lien Senior Secured Loan EURIBOR Spread 6.50% Interest Rate 10.46% Maturity Date 3/3/2030 One2023-12-310001655050Non-controlled/Non-Affiliate Investments Healthcare & Pharmaceuticals CPS Group Holdings, Inc. First Lien Senior Secured Loan LIBOR Spread 5.75% Interest Rate 10.48% Maturity Date 3/3/20252022-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty One Morgan Stanley Settlement Date 03/25/20242023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberServices: Consumer MZR Buyer, LLC First Lien Senior Secured Loan SOFR Spread 6.75% Interest Rate 11.72% Maturity Date 12/21/20262022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberForward Foreign Currency Exchange Contracts Counterparty Morgan Stanley Settlement Date 2/17/20232022-01-012022-12-310001655050bcsf:Notes8.50PercentDue2023Member2022-08-240001655050bcsf:RoadoneMemberbcsf:DelayedDrawCommitmentMember2022-12-310001655050Non-controlled/Non-Affiliated Investments High Tech Industries Gluware First Lien Senior Secured Loan Spread 9.00% (5.50% PIK) Interest Rate 14.50% Maturity Date 10/15/20252023-12-310001655050Non-controlled/Non-Affiliated Investments Services: Business Caribou Bidco Limited First Lien Senior Secured Loan - 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First Lien Senior Secured Loan SOFR Spread 6.50% Interest Rate 11.24% Maturity Date 3/6/20282022-12-310001655050Controlled Affiliate Investments Aerospace & Defense BCC Jetstream Holdings Aviation (Off I), LLC Equity Interest2023-12-310001655050Non-controlled/Non-Affiliated Investments Transportation: Cargo A&R Logistics, Inc. First Lien Senior Secured Loan SOFR Spread 6.50% Interest Rate 10.21% Maturity Date 5/5/20252022-12-310001655050us-gaap:MeasurementInputEbitdaMultipleMemberus-gaap:FairValueInputsLevel3Memberbcsf:ValuationTechniqueComparableCompanyMultipleMemberus-gaap:WarrantMembersrt:WeightedAverageMember2022-12-310001655050Non-controlled/Non-Affiliated Investments Transportation: Cargo Grammer Investment Holdings LLC Warrants2023-12-310001655050Non-controlled/Non-Affiliate Investments FIRE: Insurance Margaux Acquisition Inc. 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First Lien Senior Secured Loan CDOR Spread 5.25% Interest Rate 9.98% Maturity Date 4/30/20262022-12-310001655050Investment BCC Middle Market CLO 2018-1, LLC Acquisition Date 2/28/20222023-01-012023-12-310001655050us-gaap:InvestmentUnaffiliatedIssuerMember2023-01-012023-12-310001655050Investment ARL Holdings, LLC Acquisition Date 5/3/20192023-01-012023-12-310001655050bcsf:ServiceMasterMemberbcsf:RevolverCommitmentMember2022-12-310001655050Non-controlled/Non-Affiliated Investments Consumer Goods: Wholesale WSP First Lien Senior Secured Loan SOFR Spread 6.40% (0.75% PIK) Interest Rate 12.53% Maturity Date 4/27/20272023-12-310001655050Non-controlled/Non-Affiliated Investments Wholesale Hultec Equity Interest2023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberHotel, Gaming & Leisure Saltoun First Lien Senior Secured Loan Spread 11.00% Interest Rate 11.00% Maturity Date 4/11/20282022-12-310001655050Non-controlled/Non-Affiliated Investments Services: Business TEI Holdings Inc. First Lien Senior Secured Loan SOFR Spread 5.25% Interest Rate 10.76% Maturity Date 12/23/20262023-12-310001655050Non-controlled/Non-Affiliated Investments Consumer Goods: Non-Durable Solaray, LLC First Lien Senior Secured Loan SOFR Spread 5.75% Interest Rate 10.43% Maturity Date 9/9/20232022-12-310001655050bcsf:RevolverCommitmentMemberbcsf:WUHoldcoIncMember2023-12-310001655050Non-controlled/Non-Affiliated Investments Energy: Electicity WCI Gigawatt Purchaser First Lien Senior Secured Loan SOFR Spread 5.76% Interest Rate 11.13% Maturity Date 11/19/20272023-12-310001655050bcsf:SumitomoCreditFacilityMemberus-gaap:FairValueInputsLevel3Member2022-12-310001655050bcsf:InterestRateFloorThreeMember2023-12-310001655050Non-controlled/Non-Affiliated Investments Transportation: Consumer Toro Private Investments II, L.P. First Lien Senior Secured Loan LIBOR Spread 1.50% (7.25% PIK) Interest Rate 13.48% Maturity Date 2/28/20252022-12-310001655050bcsf:Notes8.50PercentDue2023Member2023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Thirteen Standard Chartered Settlement Date 07/18/20242023-01-012023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Three Bank of New York Mellon Settlement Date 3/5/20242023-01-012023-12-310001655050bcsf:EnergyElecticityMember2023-12-310001655050Non-controlled/Non-Affiliated Investments Environmental Industries Titan Cloud Software, Inc First Lien Senior Secured Loan - Delayed Draw SOFR Spread 6.10% Interest Rate 11.48% Maturity Date 9/7/20292023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberAutomotive JHCC Holdings, LLC First Lien Senior Secured Loan - Delayed Draw SOFR Spread 5.25% Interest Rate 10.75% Maturity Date 9/9/20252023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Five Standard Chartered Settlement Date 1/18/2023bcsf:InternationalSeniorLoanProgramLlcMember2022-12-310001655050Non-controlled/Affiliated Investments Transportation: Consumer Direct Travel, Inc Equity Interest2022-12-310001655050bcsf:EnergyOilAndGasNoncontrolledAffiliateInvestmentsMember2022-12-310001655050bcsf:MediaPublishingMember2023-01-012023-12-310001655050currency:USDbcsf:InternationalSeniorLoanProgramLlcMemberbcsf:MediaDiversifiedAndProductionMember2022-12-310001655050us-gaap:SubordinatedDebtMember2022-01-012022-12-310001655050bcsf:RevolverCommitmentMemberbcsf:DarcyPartnersMember2023-12-310001655050Investment NPC International, Inc. Acquisition Date 4/1/20212022-01-012022-12-310001655050bcsf:AAndRLogisticsIncMemberbcsf:RevolverCommitmentMember2022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberU.S. Dollar High Tech Industries NearMap First Lien Senior Secured Loan SOFR Spread 7.25% Interest Rate 12.61% Maturity Date 12/9/20292023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Bank of New York Mellon Settlement Date 1/18/20242023-01-012023-12-310001655050Investment masLabor Acquisition Date 7/1/20212022-01-012022-12-310001655050bcsf:TransportationCargoSectorMember2022-01-012022-12-310001655050bcsf:JPMCreditFacilityMember2019-04-300001655050bcsf:BccJetstreamHoldingsAviationOffILlcMemberbcsf:ControlledAffiliatedEntityMemberbcsf:EquityInterestMember2022-01-012022-12-310001655050bcsf:AsprPacAcquisitionCoLlcMemberbcsf:RevolverCommitmentMember2023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberForward Foreign Currency Exchange Contracts Counterparty Morgan Stanley Settlement Date 3/15/20232022-12-310001655050us-gaap:FairValueInputsLevel2Memberbcsf:Notes2.95PercentDueMarch2026Member2022-12-310001655050bcsf:EquityInterestInvestmentVehiclesMember2023-01-012023-12-310001655050us-gaap:RevolvingCreditFacilityMember2023-12-310001655050currency:EURbcsf:InternationalSeniorLoanProgramLlcMemberbcsf:HighTechIndustriesMember2022-12-310001655050us-gaap:EquitySecuritiesMemberus-gaap:FairValueInputsLevel3Member2023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Four Standard Chartered Settlement Date 07/18/20242023-12-310001655050bcsf:PrimePlusFivePercentageMember2023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Five Morgan Stanley Settlement Date 2/17/2023bcsf:InternationalSeniorLoanProgramLlcMember2022-01-012022-12-310001655050bcsf:IncentiveFeeBasedOnCapitalGainsMember2023-01-012023-12-310001655050us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputDiscountRateMemberbcsf:PreferredStockThreeMember2023-12-310001655050Non-controlled/Non-Affiliated Investments Construction & Building Elk Parent Holdings, LP Equity Interest2023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberbcsf:InterestRateFloorTwoMember2022-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Two Standard Chartered Settlement Date 01/17/20242023-12-310001655050bcsf:WholesaleMember2022-12-310001655050Non-controlled/Non-Affiliated Investments Media: Diversified & Production Aptus 1724 Gmbh First Lien Senior Secured Loan SOFR Spread 6.25% Interest Rate 11.78% Maturity Date 2/23/20282023-12-310001655050Non-controlled/Non-Affiliate Investments Healthcare & Pharmaceuticals Datix Bidco Limited Second Lien Senior Secured Loan SONIA Spread 7.75% Interest Rate 9.44% Maturity Date 4/27/20262022-12-310001655050Investment BCC BCSF DCB Blocker LP Interest Acquisition Date 5/16/20222022-01-012022-12-310001655050us-gaap:MeasurementInputEbitdaMultipleMemberus-gaap:FairValueInputsLevel3Memberbcsf:ValuationTechniqueComparableCompanyMultipleMemberbcsf:EquitySecuritiesTwoMembersrt:MinimumMember2022-12-310001655050bcsf:IncentiveFeeBasedOnIncomeMemberbcsf:BCSFAdvisorsLpMember2023-01-012023-12-310001655050bcsf:InvestmentHoldingsMember2022-12-310001655050bcsf:BCSFAdvisorsLpMemberbcsf:AssetCoverageRatioBelow200PercentMember2023-01-012023-12-310001655050us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberbcsf:FirstLienSeniorSecuredLoansOneMemberus-gaap:MeasurementInputComparabilityAdjustmentMember2023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberU.S. Dollar Services: Business Avalon Acquiror, Inc. First Lien Senior Secured Loan SOFR Spread 6.25% Interest Rate 10.83% Maturity Date 3/10/20282022-12-310001655050Non-controlled/Non-Affiliated Investments Media: Advertising, Printing & Publishing TGI Sport Bidco Pty Ltd First Lien Senior Secured Loan - Delayed Draw LIBOR Spread 7.00% Interest Rate 11.39% Maturity Date 4/30/20262022-12-310001655050bcsf:DarcyPartnersRCMemberbcsf:FirstLienSeniorSecuredLoanCommitmentMember2022-12-3100016550502022-10-012022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberbcsf:InvestmentsOperationsMemberbcsf:InvestmentConcentrationRiskMember2023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Goldman Sachs Settlement Date 07/18/20242023-12-310001655050Non-controlled/Non-Affiliated Investments Transportation: Cargo A&R Logistics, Inc. First Lien Senior Secured Loan SOFR Spread 6.00% Interest Rate 9.71% Maturity Date 5/5/20252022-12-310001655050bcsf:KellstromCommercialAerospaceIncMemberbcsf:RevolverCommitmentMember2022-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Four Bank of New York Mellon Settlement Date 3/3/20232022-01-012022-12-310001655050Non-controlled/Non-Affiliated Investments Healthcare & Pharmaceuticals Premier Imaging, LLC First Lien Senior Secured Loan - Delayed Draw SOFR Spread 6.00% Interest Rate 11.61% Maturity Date 1/2/20252023-12-310001655050Non-controlled/Non-Affiliated Investments Construction & Building Elk Parent Holdings, LP Equity Interest2022-12-310001655050bcsf:IncentiveFeeBasedOnIncomeAfterWaiverMember2022-01-012022-12-310001655050bcsf:TransportationCargoMember2023-12-310001655050Non-controlled/Non-Affiliate Investments FIRE: Insurance MRHT First Lien Senior Secured Loan EURIBOR Spread 5.50 % Interest Rate 7.41% Maturity Date 7/26/20282022-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Bank of New York Mellon Settlement Date 6/21/20242023-12-310001655050Non-controlled/Non-Affiliated Investments Media: Advertising, Printing & Publishing TGI Sport Bidco Pty Ltd First Lien Senior Secured Loan SOFR Spread 7.11% Interest Rate 12.47% Maturity Date 4/30/20262023-12-310001655050us-gaap:WarrantMember2023-12-310001655050bcsf:RisksRelatingToInvestmentsMember2023-01-012023-12-310001655050bcsf:EquityInterestInvestmentVehiclesMember2023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Two Bank of New York Mellon Settlement Date 3/5/20242023-01-012023-12-310001655050Non-controlled/Non-Affiliated Investments Capital Equipment FCG Acquisitions, Inc. Preferred Equity2023-12-310001655050Non-controlled/Non-Affiliated Investments Retail New Look Vision Group First Lien Senior Secured Loan - Revolver CDOR Spread 5.50% Interest Rate 10.38% Maturity Date 5/26/2026 2022-12-310001655050Non-controlled/Non-Affiliated Investments Services: Business Spring Finco BV First Lien Senior Secured Loan NIBOR Spread 6.00% Interest Rate 9.08% Maturity Date 7/15/20292022-12-310001655050bcsf:BeverageFoodAndTobaccoMember2023-12-310001655050us-gaap:RevolvingCreditFacilityMember2018-05-150001655050Forward Foreign Currency Exchange Contracts Counterparty Morgan Stanley Settlement Date 01/09/20252023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberConsumer Goods: Non-Durable FL Hawk Intermediate Holdings, Inc Second Lien Senior Secured Loan LIBOR Spread 9.00% Interest Rate 13.73% Maturity Date 8/22/20282022-12-310001655050Non-controlled/Non-Affiliated Investments Services: Business WCI Gigawatt Purchaser First Lien Senior Secured Loan - Revolver LIBOR Spread 5.75% Interest Rate 10.04% Maturity Date 11/19/20272022-12-310001655050bcsf:BeverageFoodandTobaccoSectorMember2022-12-310001655050bcsf:JPMCreditFacilityMember2020-03-202020-03-200001655050bcsf:InternationalSeniorLoanProgramLlcMemberU.S. Dollar Automotive Cardo First Lien Senior Secured Loan SOFR Spread 5.15% Interest Rate 10.54% Maturity Date 5/12/20282023-12-310001655050us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberbcsf:EquityInterestInInvestmentVehiclesMember2023-12-310001655050bcsf:NonControlledAffiliatedEntityMember2022-12-310001655050Non-controlled/Non-Affiliate Investments High Tech Industries MRI Software LLC First Lien Senior Secured Loan LIBOR Spread 5.50% Interest Rate 10.23% Maturity Date 2/10/20262022-12-310001655050Non-controlled/Non-Affiliated Investments Containers, Packaging, & Glass Iris Holding, Inc. First Lien Senior Secured Loan SOFR Spread 4.75% Interest Rate 8.94% Maturity Date 6/28/20282022-12-310001655050Non-controlled/Non-Affiliated Investments Banking, Finance, Insurance & Real Estate Morrow Sodali First Lien Senior Secured Loan - Delayed Draw SOFR Spread 5.50% Interest Rate 10.96% Maturity Date 4/25/20282023-12-310001655050Non-controlled/Non-Affiliated Investments Services: Consumer MZR Buyer, LLC First Lien Senior Secured Loan - Revolver SOFR Spread 7.00% Interest Rate 12.18% Maturity Date 12/22/20262023-12-310001655050bcsf:NonControlledAffiliatedEntityMemberbcsf:FirstLienSeniorSecuredLoanDelayedDrawMemberbcsf:WalkerEdisonFirstFurnitureCompanyLlcMember2023-12-310001655050srt:MinimumMember2020-07-022020-07-020001655050bcsf:RevolverCommitmentMemberbcsf:TaoglasMember2023-12-310001655050Non-controlled/Non-Affiliated Investments Containers, Packaging, & Glass ASP-r-pac Acquisition Co LLC First Lien Senior Secured Loan LIBOR Spread 6.00% Interest Rate 10.38% Maturity Date 12/29/20272022-12-310001655050bcsf:SumitomoCreditFacilityMember2022-12-310001655050bcsf:ConsumerGoodsWholesaleSectorMember2023-12-310001655050Investment TLC Holdco LP Acquisition Date 10/11/20192023-01-012023-12-310001655050Non-controlled/Non-Affiliated Investments Services: Consumer Surrey Bidco Limited First Lien Senior Secured Loan SONIA Spread 7.00% PIK Interest Rate 8.97% Maturity Date 5/11/20262022-12-310001655050bcsf:PreferredEquityMemberbcsf:ControlledAffiliatedEntityMemberbcsf:BainCapitalSeniorLoanProgramLlcMember2022-01-012022-12-310001655050Non-controlled/Non-Affiliated Investments Chemicals, Plastics & Rubber V Global Holdings LLC First Lien Senior Secured Loan - Revolver Maturity Date 12/22/20252022-12-310001655050bcsf:MediaBroadcastingAndSubscriptionMember2023-01-012023-12-310001655050Non-controlled/Non-Affiliated Investments FIRE: Insurance Margaux Acquisition Inc. First Lien Senior Secured Loan SOFR Spread 5.75% Interest Rate 11.23% Maturity Date 12/19/20242023-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberServices: Business AMCP Clean Acquisition Company, LLC First Lien Senior Secured Loan - Delayed Draw SOFR Spread 4.40% Interest Rate 9.79% Maturity Date 7/10/20252023-12-310001655050bcsf:MargauxUKFinanceLimitedMemberbcsf:RevolverCommitmentMember2022-12-310001655050bcsf:RocOpcoLlcMemberbcsf:RevolverCommitmentMember2022-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty One Goldman Sachs Settlement Date 07/18/20242023-01-012023-12-310001655050bcsf:NonControlledAffiliatedEntityMemberbcsf:FirstLienSeniorSecuredLoanDelayedDrawMemberbcsf:DirectTravelIncMember2023-12-310001655050Non-controlled/Non-Affiliated Investments High Tech Industries VPARK BIDCO AB First Lien Senior Secured Loan NIBOR Spread 4.00% Interest Rate 8.54% Maturity Date 3/10/20252023-12-310001655050bcsf:OctoberTwoThousandTwentySixNotesMember2023-12-310001655050us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberbcsf:EquitySecuritiesOneMemberus-gaap:MeasurementInputDiscountRateMember2022-12-310001655050bcsf:SunmedGroupHoldingsLLCMemberbcsf:RevolverCommitmentMember2022-12-310001655050Non-controlled/Non-Affiliated Investments Consumer Goods: Durable TLC Purchaser, Inc. First Lien Senior Secured Loan - Revolver SOFR Spread 6.51% Interest Rate 11.86% Maturity Date 10/13/20252023-12-310001655050currency:USDbcsf:InternationalSeniorLoanProgramLlcMemberbcsf:MediaBroadcastingAndSubscriptionMember2023-12-310001655050Non-controlled/Non-Affiliate Investments High Tech Industries Revalize, Inc. Preferred Equity2022-12-310001655050Non-controlled/Non-Affiliated Investments Telecommunications DC Blox Inc. Preferred Equity2022-12-310001655050country:IL2022-12-310001655050bcsf:AbraconGroupHoldingLlcMemberbcsf:DelayedDrawCommitmentMember2023-12-310001655050bcsf:RoadoneMemberbcsf:RevolverCommitmentMember2022-12-310001655050bcsf:StructuredProductsMemberus-gaap:FairValueInputsLevel3Member2023-12-310001655050srt:MaximumMemberus-gaap:MeasurementInputEbitdaMultipleMemberus-gaap:FairValueInputsLevel3Memberbcsf:ValuationTechniqueComparableCompanyMultipleMemberus-gaap:WarrantMember2023-12-310001655050bcsf:JPMCreditFacilityMember2020-07-022020-07-020001655050Non-controlled/Affiliated Investments Transportation: Consumer Direct Travel, Inc First Lien Senior Secured Loan - Delayed Draw SOFR Spread 6.00% Interest Rate 9.74% Maturity Date 10/2/20252022-12-310001655050bcsf:JPMCreditFacilityMember2020-01-012020-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberServices: Consumer MZR Buyer, LLC First Lien Senior Secured Loan SOFR Spread 6.75% Interest Rate 12.21% Maturity Date 12/22/20262023-12-310001655050us-gaap:PreferredStockMemberbcsf:BainCapitalSeniorLoanProgramLlcMember2022-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Bank of New York Mellon Settlement Date 5/17/20242023-01-012023-12-310001655050us-gaap:RetailSectorMember2022-12-310001655050us-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberU.S. Dollar Services: Business Avalon Acquiror, Inc. First Lien Senior Secured Loan SOFR Spread 6.25% Interest Rate 11.60% Maturity Date 3/10/20282023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Seven Standard Chartered 07/18/20242023-12-310001655050bcsf:StructuredProductsMemberus-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputComparabilityAdjustmentMember2022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMembercurrency:CADbcsf:MediaDiversifiedAndProductionMember2023-12-310001655050Non-controlled/Non-Affiliated Investments Telecommunications DC Blox Inc. Equity Interest2022-12-310001655050Non-controlled/Non-Affiliated Investments Hospitality Holdings PPX Preferred Equity 22022-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberHigh Tech Industries AMI US Holdings Inc. First Lien Senior Secured Loan - Revolver SOFR Maturity Date 4/1/2025 One2023-12-310001655050MZR Aggregator Equity Interest2023-01-012023-06-300001655050us-gaap:MeasurementInputEbitdaMultipleMemberus-gaap:FairValueInputsLevel3Memberbcsf:ValuationTechniqueComparableCompanyMultipleMemberus-gaap:WarrantMembersrt:WeightedAverageMember2023-12-310001655050country:US2022-01-012022-12-310001655050bcsf:BainCapitalSeniorLoanProgramLlcMemberConsumer Goods: Durable New Milani Group LLC First Lien Senior Secured Loan SOFR Spread 5.50% Interest Rate 10.96% Maturity Date 6/6/20242023-12-310001655050Non-controlled/Non-Affiliated Investments Construction & Building Service Master First Lien Senior Secured Loan SOFR Spread 6.00% (1.00% PIK) Interest Rate 12.65% Maturity Date 8/16/20272023-12-310001655050Investment AQ Software Corporation Acquisition Date 12/29/20222022-01-012022-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Bank of New York Mellon Settlement Date 2/7/20242023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberAustralian Dollar Services: Consumer Zeppelin BidCo Pty Limited First Lien Senior Secured Loan BBSY Spread 5.00% Interest Rate 9.15% Maturity Date 7/12/20242023-12-310001655050bcsf:AerospaceAndDefenseSectorMember2022-12-310001655050Non-controlled/Non-Affiliated Investments Construction & Building Service Master First Lien Senior Secured Loan - Revolver SOFR Spread 8.50% Interest Rate 12.94% Maturity Date 8/16/20272022-12-310001655050bcsf:CongressWealthMemberbcsf:RevolverCommitmentMember2023-12-310001655050Non-controlled/Non-Affiliated Investments Beverage, Food & Tobacco Arctic Glacier U.S.A., Inc. First Lien Senior Secured Loan SOFR Spread 6.50% (4.00% PIK) Interest Rate 16.14% Maturity Date 5/24/20282023-12-310001655050country:LU2023-12-310001655050bcsf:Notes2019OneMember2022-01-012022-12-310001655050bcsf:FirstLienSeniorSecuredLoanMemberbcsf:NonControlledAffiliatedEntityMemberbcsf:DirectTravelIncMember2022-12-310001655050Investment Ansett Aviation Training Acquisition Date 3/24/20222023-01-012023-12-310001655050Non-controlled/Non-Affiliated Investments Services: Business Parcel2Go First Lien Senior Secured Loan SONIA Spread 3.25% (3.00% PIK) Interest Rate 11.44% Maturity Date 7/17/20282023-12-310001655050Non-controlled/Non-Affiliated Investments Services: Business masLabor First Lien Senior Secured Loan LIBOR Spread 7.50% Interest Rate 11.24% Maturity Date 7/1/20272022-12-3100016550502021-09-300001655050bcsf:Notes2019OneMember2019-08-280001655050bcsf:WholesaleMember2022-01-012022-12-310001655050us-gaap:MeasurementInputEbitdaMultipleMemberus-gaap:FairValueInputsLevel3Memberus-gaap:PreferredStockMemberbcsf:ValuationTechniqueComparableCompanyMultipleMember2022-12-310001655050Non-controlled/Non-Affiliated Investments Wholesale Blackbird Purchaser, Inc. First Lien Senior Secured Loan SOFR Spread 5.50% Interest Rate 10.86% Maturity Date 12/19/20302023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberBritish Pound FIRE: Finance Parmenion First Lien Senior Secured Loan SONIA Spread 5.75% Interest Rate 8.68% Maturity Date 5/11/20292022-12-310001655050Non-controlled/Non-Affiliated Investments Transportation: Cargo ARL Holdings, Equity Interest One2023-12-310001655050us-gaap:FairValueInputsLevel3Memberbcsf:SubordinatedNoteInInvestmentVehiclesMember2022-12-310001655050us-gaap:MeasurementInputEbitdaMultipleMemberus-gaap:FairValueInputsLevel3Memberbcsf:ValuationTechniqueComparableCompanyMultipleMemberbcsf:EquitySecuritiesTwoMember2023-12-310001655050bcsf:RevolverCommitmentMemberbcsf:WorldInsuranceMember2022-12-310001655050bcsf:InvestmentHoldingsAndCashEquivalentsMember2022-12-310001655050bcsf:BccMiddleMarketClo20181LlcMemberbcsf:Notes2018OneMember2018-09-280001655050bcsf:InternationalSeniorLoanProgramLlcMemberForward Foreign Currency Exchange Contracts Counterparty Five Standard Chartered Settlement Date 1/18/20232022-01-012022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberBritish Pound Healthcare & Pharmaceuticals Datix Bidco Limited First Lien Senior Secured Loan - Revolver SONIA Spread 4.50% Interest Rate 9.69% Maturity Date 10/28/20242023-12-3100016550502023-09-300001655050Non-controlled/Non-Affiliated Investments High Tech Industries Ventiv Topco, Inc. Equity Interest2023-12-3100016550502022-01-012022-12-310001655050bcsf:OtherGeneralAndAdministrativeExpenseMemberbcsf:AdministratorMember2022-01-012022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberForward Foreign Currency Exchange Contracts Counterparty One Morgan Stanley Settlement Date 1/9/20232022-01-012022-12-310001655050Non-controlled/Non-Affiliated Investments High Tech Industries Utimaco First Lien Senior Secured Loan SOFR Spread 6.68% Interest Rate 11.99% Maturity Date 5/14/2029 One2023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberBritish Pound Healthcare & Pharmaceuticals Datix Bidco Limited Second Lien Senior Secured Loan SONIA Spread 7.75% Interest Rate 11.93% Maturity Date 4/27/20262023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMembercurrency:NOK2022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberForward Foreign Currency Exchange Contracts Counterparty Nine Standard Chartered Settlement Date 1/18/20232022-01-012022-12-310001655050Non-controlled/Non-Affiliated Investments Healthcare & Pharmaceuticals Apollo Intelligence First Lien Senior Secured Loan SOFR Spread 5.75% Interest Rate 11.12% Maturity Date 6/1/20282023-12-310001655050country:IE2022-12-310001655050Non-controlled/Non-Affiliated Investments Services: Business Chamber Bidco Limited First Lien Senior Secured Loan LIBRO Spread 5.50% Interest Rate 9.28% Maturity Date 6/7/20282022-12-310001655050Non-controlled/Non-Affiliated Investments FIRE: Finance Congress Wealth Equity Interest2023-12-310001655050bcsf:MarchTwoThousandTwentySixNotesMember2021-12-310001655050Non-controlled/Non-Affiliated Investments Consumer Goods: Wholesale WSP Initial Term Loan First Lien Senior Secured Loan - Delayed Draw Maturity Date 4/27/20272022-12-310001655050Non-controlled/Non-Affiliated Investments Consumer Goods: Durable TLC Purchaser, Inc. First Lien Senior Secured Loan SOFR Spread 2.26% (6.25% PIK) Interest Rate 14.15% Maturity Date 10/13/20252023-12-310001655050Non-controlled/Non-Affiliated Investments Transportation: Cargo A&R Logistics, Inc. First Lien Senior Secured Loan SOFR Spread 6.00% Interest Rate 11.48% Maturity Date 5/5/20252023-12-310001655050U.S. Dollar Services: Business Smartronix First Lien Senior Secured Loan LIBOR Spread 6.00% Interest Rate 10.17% Maturity Date 11/23/2028bcsf:InternationalSeniorLoanProgramLlcMember2022-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Standard Chartered Settlement Date 01/17/20242023-01-012023-12-310001655050bcsf:GspHoldingsLLCMemberbcsf:RevolverCommitmentMember2023-12-310001655050srt:MaximumMemberus-gaap:MeasurementInputEbitdaMultipleMemberus-gaap:FairValueInputsLevel3Memberbcsf:EquitySecuritiesTwoMemberbcsf:ValuationTechniqueComparableCompanyMultipleMember2022-12-310001655050bcsf:CapitalEquipmentSectorMember2022-01-012022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberU.S. Dollar High Tech Industries Utimaco First Lien Senior Secured Loan SOFR Spread 6.68% Interest Rate 11.99% Maturity Date 5/14/20292023-12-310001655050Non-controlled/Non-Affiliated Investments High Tech Industries Continued VPARK BIDCO AB First Lien Senior Secured Loan NIBOR Spread 4.00% Interest Rate 7.12% Maturity Date 3/10/20252022-12-310001655050Investment Toro Private Investments II, L.P. Acquisition Date 4/2/20192022-01-012022-12-310001655050country:AU2023-12-310001655050bcsf:TransportationConsumerSectorMember2023-12-310001655050country:KY2022-01-012022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberForward Foreign Currency Exchange Contracts Counterparty Four Morgan Stanley Settlement 01/18/20232022-01-012022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberForward Foreign Currency Exchange Contracts Counterparty One Standard Chartered Settlement Date 1/18/20232022-01-012022-12-310001655050bcsf:ConsumerGoodsNonDurableSectorMember2022-01-012022-12-310001655050us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberbcsf:SecondLienSeniorSecuredLoanMemberus-gaap:MeasurementInputComparabilityAdjustmentMembersrt:WeightedAverageMember2023-12-310001655050bcsf:NonControlledAffiliatedEntityMember2021-12-310001655050bcsf:Notes2019OneMember2023-12-310001655050Non-controlled/Non-Affiliated Investments High Tech Industries Cloud Technology Solutions (CTS) First Lien Senior Secured Loan SONIA Spread 4.00% (4.00% PIK) Interest Rate 13.19% Maturity Date 1/3/20302023-12-310001655050Controlled Affiliate Investments Aerospace & Defense BCC Jetstream Holdings Aviation (Off I), LLC Equity Interest2022-12-310001655050bcsf:MriSoftwareLlcMemberbcsf:RevolverCommitmentMember2022-12-310001655050bcsf:IncentiveFeeBasedOnIncomeMemberbcsf:BCSFAdvisorsLpMember2022-01-012022-12-310001655050Non-controlled/Non-Affiliated Investments High Tech Industries Revalize, Inc. First Lien Senior Secured Loan - Revolver SOFR Spread 5.85% Interest Rate 11.20% Maturity Date 4/15/20272023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Nine Standard Chartered Settlement Date 07/18/20242023-01-012023-12-310001655050us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberbcsf:SecondLienSeniorSecuredLoanMemberus-gaap:MeasurementInputComparabilityAdjustmentMember2023-12-310001655050Non-controlled/Non-Affiliate Investments High Tech Industries Cloud Technology Solutions (CTS) First Lien Senior Secured Loan - Revolver 2022-12-310001655050bcsf:ControlledAffiliatedEntityMemberbcsf:EquityInterestMemberbcsf:GaleAviationOffshoreCoMember2023-01-012023-12-310001655050Non-controlled/Non-Affiliated Investments High Tech Industries Continued Swoogo LLC First Lien Senior Secured Loan LIBOR Spread 8.00% Interest Rate 12.24% Maturity Date 12/9/20262022-12-310001655050bcsf:MediaDiversifiedAndProductionMember2022-01-012022-12-310001655050bcsf:ElementBuyerIncMemberbcsf:RevolverCommitmentMember2022-12-310001655050Non-controlled/Non-Affiliated Investments Transportation: Cargo ARL Holdings, Equity Interest2023-12-310001655050bcsf:ValuationTechniqueCollateralCoverageAnalysisMemberbcsf:FirstLienSeniorSecuredLoansFiveMemberus-gaap:FairValueInputsLevel3Memberbcsf:MeasurementInputRecoveryRateMember2023-12-310001655050bcsf:FirstLienSeniorSecuredLoanMemberbcsf:NonControlledAffiliatedEntityMemberbcsf:DirectTravelIncTwoMember2023-01-012023-12-310001655050Forward Foreign Currency Exchange Contracts Counterparty Morgan Stanley Settlement Date 06/10/2025 2023-01-012023-12-310001655050bcsf:JPMCreditFacilityMember2021-01-012021-12-310001655050Non-controlled/Non-Affiliated Investments Aerospace & Defense Robinson Helicopter Equity Interest 2023-12-310001655050bcsf:AerospaceAndDefenseSectorControlledAffiliatedInvestmentsMember2022-12-310001655050bcsf:FireFinanceMember2022-12-310001655050bcsf:RevolverCommitmentMemberbcsf:TitanCloudSoftwareIncMember2023-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberForward Foreign Currency Exchange Contracts Counterparty Four Standard Chartered Settlement Date 1/18/20232022-01-012022-12-310001655050Non-controlled/Non-Affiliated Investments Banking, Finance, Insurance & Real Estate Morrow Sodali First Lien Senior Secured Loan - Delayed Draw SOFR Spread 5.00% Interest Rate 9.23% Maturity Date 4/25/20282022-12-310001655050bcsf:InternationalSeniorLoanProgramLlcMemberNon-controlled/Non-Affiliate Investments High Tech Industries CB Nike IntermediateCo Ltd First Lien Senior Secured Loan - Revolver Maturity Date 10/31/20252023-12-31