00013217413-312023Q2FALSEGLADSTONE INVESTMENT CORPORATION\DE00013217412022-04-012022-09-300001321741us-gaap:CommonStockMember2022-04-012022-09-300001321741gain:A500NotesDue2026Member2022-04-012022-09-300001321741gain:A4875NotesDue2028Member2022-04-012022-09-3000013217412022-10-31xbrli:shares0001321741us-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-09-30iso4217:USD0001321741us-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-03-310001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2022-09-300001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2022-03-310001321741us-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2022-09-300001321741us-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2022-03-3100013217412022-09-3000013217412022-03-310001321741gain:TheAdviserMember2022-09-300001321741gain:TheAdviserMember2022-03-310001321741gain:TheAdministratorMember2022-09-300001321741gain:TheAdministratorMember2022-03-31iso4217:USDxbrli:shares0001321741us-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-07-012022-09-300001321741us-gaap-supplement:InvestmentUnaffiliatedIssuerMember2021-07-012021-09-300001321741us-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-04-012022-09-300001321741us-gaap-supplement:InvestmentUnaffiliatedIssuerMember2021-04-012021-09-300001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2022-07-012022-09-300001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2021-07-012021-09-300001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2022-04-012022-09-300001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2021-04-012021-09-300001321741us-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2022-07-012022-09-300001321741us-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2021-07-012021-09-300001321741us-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2022-04-012022-09-300001321741us-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2021-04-012021-09-300001321741us-gaap:CashAndCashEquivalentsMember2022-07-012022-09-300001321741us-gaap:CashAndCashEquivalentsMember2021-07-012021-09-300001321741us-gaap:CashAndCashEquivalentsMember2022-04-012022-09-300001321741us-gaap:CashAndCashEquivalentsMember2021-04-012021-09-3000013217412022-07-012022-09-3000013217412021-07-012021-09-3000013217412021-04-012021-09-300001321741us-gaap:OtherInvestmentCompaniesMember2022-07-012022-09-300001321741us-gaap:OtherInvestmentCompaniesMember2021-07-012021-09-300001321741us-gaap:OtherInvestmentCompaniesMember2022-04-012022-09-300001321741us-gaap:OtherInvestmentCompaniesMember2021-04-012021-09-3000013217412021-03-3100013217412022-04-012022-06-3000013217412021-04-012021-06-3000013217412022-06-3000013217412021-06-3000013217412021-09-300001321741gain:InvestmentUnaffiliatedAndAffiliatedIssuerExcludingOtherMember2022-04-012022-09-300001321741gain:InvestmentUnaffiliatedAndAffiliatedIssuerExcludingOtherMember2021-04-012021-09-300001321741gain:TheAdviserMember2022-04-012022-09-300001321741gain:TheAdviserMember2021-04-012021-09-300001321741gain:TheAdministratorMember2022-04-012022-09-300001321741gain:TheAdministratorMember2021-04-012021-09-300001321741Ginsey Home Solutions, Inc.2022-08-012022-08-31xbrli:pure0001321741gain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-09-300001321741gain:BuildingsAndRealEstateMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-09-300001321741Dema/Mai Holdings, Inc – Line of Credit2022-09-300001321741Dema/Mai Holdings, Inc – Term Debt2022-09-300001321741gain:DiversifiedConglomerateManufacturingMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-09-300001321741Phoenix Door Systems, Inc – Line of Credit2022-09-300001321741Phoenix Door Systems, Inc – Line of Credit2022-04-012022-09-300001321741Phoenix Door Systems, Inc. – Term Debt2022-09-300001321741gain:DiversifiedConglomerateServicesMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-09-300001321741Counsel Press, Inc. – Term Debt 12022-09-300001321741Counsel Press, Inc. – Term Debt 22022-09-300001321741Horizon Facilities Services, Inc. – Term Debt2022-09-300001321741Mason West, LLC – Term Debt2022-09-300001321741gain:HealthcareEducationAndChildcareMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-09-300001321741Educators Resource, Inc. – Term Debt2022-09-300001321741gain:HomeAndOfficeFurnishingsHousewaresAndDurableConsumerProductsMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-09-300001321741Brunswick Bowling Products, Inc. – Term Debt 12022-09-300001321741Brunswick Bowling Products, Inc. – Term Debt 22022-09-300001321741Ginsey Home Solutions, Inc. – Term Debt2022-09-300001321741gain:HotelsMotelsInnsAndGamingTotalMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-09-300001321741Nocturne Villa Rentals, Inc. – Line of Credit2022-09-300001321741Nocturne Villa Rentals, Inc. – Term Debt2022-09-300001321741gain:LeisureAmusementMotionPicturesAndEntertainmentMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-09-300001321741Schylling, Inc. – Term Debt2022-09-300001321741us-gaap-supplement:InvestmentUnaffiliatedIssuerMembergain:DebtSecuritiesSecuredSecondLienDebtMember2022-09-300001321741us-gaap-supplement:InvestmentUnaffiliatedIssuerMembergain:DebtSecuritiesSecuredSecondLienDebtMembergain:AerospaceAndDefenseMember2022-09-300001321741Galaxy Technologies Holdings, Inc. – Term Debt 12022-09-300001321741Galaxy Technologies Holdings, Inc. – Term Debt 22022-09-300001321741us-gaap-supplement:InvestmentUnaffiliatedIssuerMembergain:AutomobileMembergain:DebtSecuritiesSecuredSecondLienDebtMember2022-09-300001321741Country Club Enterprises, LLC – Term Debt2022-09-300001321741Country Club Enterprises, LLC – Guaranty2022-04-012022-09-300001321741Country Club Enterprises, LLC – Guaranty2022-09-300001321741gain:CargoTransportMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMembergain:DebtSecuritiesSecuredSecondLienDebtMember2022-09-300001321741Diligent Delivery Systems – Term Debt2022-09-300001321741gain:MachineryNonAgricultureNonConstructionAndNonElectronicMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMembergain:DebtSecuritiesSecuredSecondLienDebtMember2022-09-300001321741SFEG Holdings, Inc. – Term Debt 12022-09-300001321741SFEG Holdings, Inc. – Term Debt 22022-09-300001321741gain:PreferredEquityMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-09-300001321741gain:BuildingsAndRealEstateMembergain:PreferredEquityMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-09-300001321741Dema/Mai Holdings, Inc - Preferred Equity2022-09-300001321741gain:DiversifiedConglomerateServicesMembergain:PreferredEquityMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-09-300001321741Counsel Press, Inc. – Preferred Stock2022-09-300001321741Horizon Facilities Services, Inc. – Preferred Stock2022-09-300001321741Mason West, LLC – Preferred Stock2022-09-300001321741gain:PreferredEquityMembergain:HealthcareEducationAndChildcareMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-09-300001321741Educators Resource, Inc. – Preferred Stock2022-09-300001321741gain:HomeAndOfficeFurnishingsHousewaresAndDurableConsumerProductsMembergain:PreferredEquityMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-09-300001321741Brunswick Bowling Products, Inc. – Preferred Stock2022-09-300001321741Ginsey Home Solutions, Inc. – Preferred Stock2022-09-300001321741gain:HotelsMotelsInnsAndGamingTotalMembergain:PreferredEquityMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-09-300001321741Nocturne Villa Rentals, Inc. – Preferred Stock2022-09-300001321741gain:LeisureAmusementMotionPicturesAndEntertainmentMembergain:PreferredEquityMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-09-300001321741Schylling, Inc. – Preferred Stock2022-09-300001321741gain:PreferredEquityMembergain:MachineryNonAgricultureNonConstructionAndNonElectronicMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-09-300001321741SFEG Holdings, Inc. – Preferred Stock2022-09-300001321741gain:CommonEquityEquivalentsMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-09-300001321741gain:CommonEquityEquivalentsMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMembergain:AerospaceAndDefenseMember2022-09-300001321741Galaxy Technologies Holdings, Inc. – Common Stock2022-09-300001321741gain:CommonEquityEquivalentsMembergain:CargoTransportMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-09-300001321741Diligent Delivery Systems – Common Stock Warrants2022-09-300001321741Phoenix Door Systems, Inc. – Common Stock2022-09-300001321741gain:CommonEquityEquivalentsMembergain:HomeAndOfficeFurnishingsHousewaresAndDurableConsumerProductsMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-09-300001321741Ginsey Home Solutions, Inc. – Common Stock2022-09-300001321741gain:CommonEquityEquivalentsMembergain:MachineryNonAgricultureNonConstructionAndNonElectronicMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-09-300001321741SFEG Holdings, Inc. – Common Stock2022-09-300001321741gain:CommonEquityEquivalentsMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMembergain:PersonalAndNonDurableConsumerProductsManufacturingOnlyMember2022-09-300001321741Funko Acquisition Holdings, LLC – Common Units2022-09-300001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:DebtSecuritiesSecuredFirstLienDebtMember2022-09-300001321741gain:DiversifiedConglomerateManufacturingMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:DebtSecuritiesSecuredFirstLienDebtMember2022-09-300001321741Edge Adhesives Holdings, Inc.– Term Debt2022-09-300001321741gain:DiversifiedConglomerateServicesMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:DebtSecuritiesSecuredFirstLienDebtMember2022-09-300001321741ImageWorks Display and Marketing Group, Inc. – Term Debt2022-09-300001321741J.R. Hobbs Co. - Atlanta, LLC – Line of Credit2022-09-300001321741J.R. Hobbs Co. - Atlanta, LLC - Term Debt 12022-09-300001321741J.R. Hobbs Co. - Atlanta, LLC – Term Debt 22022-09-300001321741J.R. Hobbs Co. - Atlanta, LLC – Term Debt 32022-09-300001321741The Maids International, LLC – Term Debt 2022-09-300001321741gain:HomeAndOfficeFurnishingsHousewaresAndDurableConsumerProductsMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:DebtSecuritiesSecuredFirstLienDebtMember2022-09-300001321741Old World Christmas, Inc. – Secured First Lien Term Loan2022-09-300001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:DebtSecuritiesSecuredFirstLienDebtMembergain:MiningSteelIronAndNonPreciousMetalsTotalMember2022-09-300001321741Utah Pacific Bridge & Steel, Ltd., 22022-09-300001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:DebtSecuritiesSecuredFirstLienDebtMembergain:PersonalAndNonDurableConsumerProductsManufacturingOnlyMember2022-09-300001321741The Mountain Corporation – Line of Credit 12022-09-300001321741The Mountain Corporation – Line of Credit 22022-09-300001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:TelecommunicationsMembergain:DebtSecuritiesSecuredFirstLienDebtMember2022-09-300001321741B+T Group Acquisition, Inc. – Line of Credit2022-09-300001321741B+T Group Acquisition, Inc.(L) – Term Debt 22022-09-300001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:DebtSecuritiesSecuredSecondLienDebtMember2022-09-300001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:DebtSecuritiesSecuredSecondLienDebtMembergain:ChemicalsPlasticsAndRubberMember2022-09-300001321741PSI Molded Plastics, Inc. – Term Debt2022-09-300001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:DebtSecuritiesSecuredSecondLienDebtMembergain:PersonalAndNonDurableConsumerProductsManufacturingOnlyMember2022-09-300001321741The Mountain Corporation – Term Debt 2022-09-300001321741The Mountain Corporation – Delayed Draw Term Debt2022-09-300001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:PreferredEquityMember2022-09-300001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:PreferredEquityMembergain:ChemicalsPlasticsAndRubberMember2022-09-300001321741PSI Molded Plastics, Inc. – Preferred Stock(2022-09-300001321741gain:DiversifiedConglomerateManufacturingMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:PreferredEquityMember2022-09-300001321741Edge Adhesives Holdings, Inc. – Preferred Stock2022-09-300001321741gain:DiversifiedConglomerateServicesMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:PreferredEquityMember2022-09-300001321741ImageWorks Display and Marketing Group, Inc. – Preferred Stock2022-09-300001321741J.R. Hobbs Co. – Atlanta, LLC – Preferred Stock2022-09-300001321741The Maids International, LLC – Preferred Stock2022-09-300001321741gain:HomeAndOfficeFurnishingsHousewaresAndDurableConsumerProductsMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:PreferredEquityMember2022-09-300001321741Old World Christmas, Inc. – Preferred Stock2022-09-300001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:PreferredEquityMembergain:MiningSteelIronAndNonPreciousMetalsTotalMember2022-09-300001321741Utah Pacific Bridge & Steel, Ltd. - Preferred Stock2022-09-300001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:PreferredEquityMembergain:PersonalAndNonDurableConsumerProductsManufacturingOnlyMember2022-09-300001321741The Mountain Corporation – Preferred Stock(2022-09-300001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:TelecommunicationsMembergain:PreferredEquityMember2022-09-300001321741B+T Group Acquisition, Inc.– Preferred Stock2022-09-300001321741gain:CommonEquityEquivalentsMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2022-09-300001321741gain:DiversifiedConglomerateServicesMembergain:CommonEquityEquivalentsMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2022-09-300001321741Nth Degree Investment Group, LLC – Common Stock2022-09-300001321741gain:CommonEquityEquivalentsMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:PersonalAndNonDurableConsumerProductsManufacturingOnlyMember2022-09-300001321741The Mountain Corporation – Common Stock2022-09-300001321741gain:CommonEquityEquivalentsMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:TelecommunicationsMember2022-09-300001321741B+T Group Acquisition, Inc.(L) – Common Stock Warrants2022-09-300001321741gain:CommonEquityEquivalentsMemberus-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2022-09-300001321741gain:CommonEquityEquivalentsMembergain:LeisureAmusementMotionPicturesAndEntertainmentMemberus-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2022-09-300001321741Gladstone SOG Investments, Inc. - Common Stock(2022-09-300001321741us-gaap:CollateralPledgedMember2022-09-300001321741gain:FunkoAcquisitionHoldingsLLCMember2022-09-300001321741gain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-03-310001321741gain:DiversifiedConglomerateManufacturingMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-03-310001321741Phoenix Door Systems, Inc – Line of Credit,2022-03-310001321741Phoenix Door Systems, Inc – Line of Credit,2021-04-012022-03-310001321741Phoenix Door Systems, Inc. – Term Debt2022-03-310001321741gain:DiversifiedConglomerateServicesMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-03-310001321741Bassett Creek Services, Inc. – Term Debt2022-03-310001321741Counsel Press, Inc. – Term Debt 12022-03-310001321741Counsel Press, Inc. – Term Debt 22022-03-310001321741Horizon Facilities Services, Inc. – Term Debt2022-03-310001321741Mason West, LLC – Term Debt2022-03-310001321741gain:HealthcareEducationAndChildcareMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-03-310001321741Educators Resource, Inc. – Term Debt2022-03-310001321741gain:HomeAndOfficeFurnishingsHousewaresAndDurableConsumerProductsMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-03-310001321741Brunswick Bowling Products, Inc. – Term Debt 12022-03-310001321741Brunswick Bowling Products, Inc. – Term Debt 22022-03-310001321741gain:HotelsMotelsInnsAndGamingTotalMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-03-310001321741Nocturne Villa Rentals, Inc. – Line of Credit2022-03-310001321741Nocturne Villa Rentals, Inc. – Term Debt2022-03-310001321741gain:LeisureAmusementMotionPicturesAndEntertainmentMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-03-310001321741Schylling, Inc. – Term Debt2022-03-310001321741us-gaap-supplement:InvestmentUnaffiliatedIssuerMembergain:DebtSecuritiesSecuredSecondLienDebtMember2022-03-310001321741us-gaap-supplement:InvestmentUnaffiliatedIssuerMembergain:DebtSecuritiesSecuredSecondLienDebtMembergain:AerospaceAndDefenseMember2022-03-310001321741Galaxy Technologies Holdings, Inc. – Term Debt 12022-03-310001321741Galaxy Technologies Holdings, Inc. – Term Debt 22022-03-310001321741us-gaap-supplement:InvestmentUnaffiliatedIssuerMembergain:AutomobileMembergain:DebtSecuritiesSecuredSecondLienDebtMember2022-03-310001321741Country Club Enterprises, LLC – Term Debt2022-03-310001321741Country Club Enterprises, LLC – Guaranty2021-04-012022-03-310001321741Country Club Enterprises, LLC - Guaranty2022-03-310001321741gain:CargoTransportMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMembergain:DebtSecuritiesSecuredSecondLienDebtMember2022-03-310001321741Diligent Delivery Systems – Term Debt2022-03-310001321741gain:HomeAndOfficeFurnishingsHousewaresAndDurableConsumerProductsMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMembergain:DebtSecuritiesSecuredSecondLienDebtMember2022-03-310001321741Ginsey Home Solutions, Inc. – Term Debt2022-03-310001321741Ginsey Home Solutions, Inc.gain:DebtSecuritiesSecuredSecondLienDebtMember2022-08-310001321741gain:MachineryNonAgricultureNonConstructionAndNonElectronicMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMembergain:DebtSecuritiesSecuredSecondLienDebtMember2022-03-310001321741SFEG Holdings, Inc. – Term Debt 12022-03-310001321741SFEG Holdings, Inc. – Term Debt 22022-03-310001321741gain:PreferredEquityMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-03-310001321741gain:DiversifiedConglomerateServicesMembergain:PreferredEquityMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-03-310001321741Bassett Creek Services, Inc. – Preferred Stock2022-03-310001321741Counsel Press, Inc. – Preferred Stock2022-03-310001321741Horizon Facilities Services, Inc. – Preferred Stock2022-03-310001321741Mason West, LLC – Preferred Stock2022-03-310001321741gain:PreferredEquityMembergain:HealthcareEducationAndChildcareMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-03-310001321741Educators Resource, Inc. – Preferred Stock2022-03-310001321741gain:HomeAndOfficeFurnishingsHousewaresAndDurableConsumerProductsMembergain:PreferredEquityMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-03-310001321741Brunswick Bowling Products, Inc. – Preferred Stock2022-03-310001321741Ginsey Home Solutions, Inc. – Preferred Stock2022-03-310001321741gain:HotelsMotelsInnsAndGamingTotalMembergain:PreferredEquityMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-03-310001321741Nocturne Villa Rentals, Inc. – Preferred Stock2022-03-310001321741gain:LeisureAmusementMotionPicturesAndEntertainmentMembergain:PreferredEquityMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-03-310001321741Schylling, Inc. – Preferred Stock2022-03-310001321741gain:PreferredEquityMembergain:MachineryNonAgricultureNonConstructionAndNonElectronicMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-03-310001321741SFEG Holdings, Inc. – Preferred Stock2022-03-310001321741gain:CommonEquityEquivalentsMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-03-310001321741gain:CommonEquityEquivalentsMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMembergain:AerospaceAndDefenseMember2022-03-310001321741Galaxy Technologies Holdings, Inc. – Common Stock2022-03-310001321741gain:CommonEquityEquivalentsMembergain:CargoTransportMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-03-310001321741Diligent Delivery Systems – Common Stock Warrants2022-03-310001321741gain:DiversifiedConglomerateManufacturingMembergain:CommonEquityEquivalentsMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-03-310001321741Phoenix Door Systems, Inc. – Common Stock2022-03-310001321741gain:CommonEquityEquivalentsMembergain:HomeAndOfficeFurnishingsHousewaresAndDurableConsumerProductsMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-03-310001321741Ginsey Home Solutions, Inc. – Common Stock2022-03-310001321741gain:CommonEquityEquivalentsMembergain:MachineryNonAgricultureNonConstructionAndNonElectronicMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMember2022-03-310001321741SFEG Holdings, Inc. – Common Stock2022-03-310001321741gain:CommonEquityEquivalentsMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMembergain:PersonalAndNonDurableConsumerProductsManufacturingOnlyMember2022-03-310001321741Funko Acquisition Holdings, LLC – Common Units2022-03-310001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:DebtSecuritiesSecuredFirstLienDebtMember2022-03-310001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:DebtSecuritiesSecuredFirstLienDebtMembergain:ChemicalsPlasticsAndRubberMember2022-03-310001321741PSI Molded Plastics, Inc. – Term Debt2022-03-310001321741gain:DiversifiedConglomerateManufacturingMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:DebtSecuritiesSecuredFirstLienDebtMember2022-03-310001321741Edge Adhesives Holdings, Inc. – Term Debt 2022-03-310001321741gain:DiversifiedConglomerateServicesMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:DebtSecuritiesSecuredFirstLienDebtMember2022-03-310001321741ImageWorks Display and Marketing Group, Inc. – Term Debt2022-03-310001321741J.R. Hobbs Co. - Atlanta, LLC - Term Debt 12022-03-310001321741J.R. Hobbs Co. - Atlanta, LLC - Term Debt 22022-03-310001321741J.R. Hobbs Co. - Atlanta, LLC - Term Debt 32022-03-310001321741J.R. Hobbs Co. - Atlanta, LLC - Guaranty2020-04-012021-03-310001321741J.R. Hobbs Co. - Atlanta, LLC - Guaranty2022-03-310001321741The Maids International, LLC – Term Debt2022-03-310001321741gain:HomeAndOfficeFurnishingsHousewaresAndDurableConsumerProductsMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:DebtSecuritiesSecuredFirstLienDebtMember2022-03-310001321741Old World Christmas, Inc. – Secured First Lien Term Loan2022-03-310001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:DebtSecuritiesSecuredFirstLienDebtMembergain:MiningSteelIronAndNonPreciousMetalsTotalMember2022-03-310001321741Utah Pacific Bridge & Steel, Ltd., 12022-03-310001321741Utah Pacific Bridge & Steel, Ltd., 22022-03-310001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:DebtSecuritiesSecuredFirstLienDebtMembergain:PersonalAndNonDurableConsumerProductsManufacturingOnlyMember2022-03-310001321741The Mountain Corporation 12022-03-310001321741The Mountain Corporation 22022-03-310001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:TelecommunicationsMembergain:DebtSecuritiesSecuredFirstLienDebtMember2022-03-310001321741B+T Group Acquisition, Inc. – Line of Credit2022-03-310001321741B+T Group Acquisition, Inc. – Term Debt2022-03-310001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:DebtSecuritiesSecuredSecondLienDebtMember2022-03-310001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:DebtSecuritiesSecuredSecondLienDebtMembergain:PersonalAndNonDurableConsumerProductsManufacturingOnlyMember2022-03-310001321741The Mountain Corporation – Term Debt2022-03-310001321741The Mountain Corporation – Delayed Draw Term Debt2022-03-310001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:PreferredEquityMember2022-03-310001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:PreferredEquityMembergain:ChemicalsPlasticsAndRubberMember2022-03-310001321741PSI Molded Plastics, Inc. – Preferred Stock2022-03-310001321741gain:DiversifiedConglomerateManufacturingMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:PreferredEquityMember2022-03-310001321741Edge Adhesives Holdings, Inc. – Preferred Stock2022-03-310001321741gain:DiversifiedConglomerateServicesMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:PreferredEquityMember2022-03-310001321741ImageWorks Display and Marketing Group, Inc. – Preferred Stock2022-03-310001321741J.R. Hobbs Co. – Atlanta, LLC – Preferred Stock2022-03-310001321741The Maids International, LLC – Preferred Stock2022-03-310001321741gain:HomeAndOfficeFurnishingsHousewaresAndDurableConsumerProductsMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:PreferredEquityMember2022-03-310001321741Old World Christmas, Inc. – Preferred Stock2022-03-310001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:PreferredEquityMembergain:MiningSteelIronAndNonPreciousMetalsTotalMember2022-03-310001321741Utah Pacific Bridge & Steel, Ltd. - Preferred Stock2022-03-310001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:PreferredEquityMembergain:PersonalAndNonDurableConsumerProductsManufacturingOnlyMember2022-03-310001321741The Mountain Corporation – Preferred Stock2022-03-310001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:TelecommunicationsMembergain:PreferredEquityMember2022-03-310001321741B+T Group Acquisition, Inc. – Preferred Stock2022-03-310001321741gain:CommonEquityEquivalentsMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2022-03-310001321741gain:DiversifiedConglomerateServicesMembergain:CommonEquityEquivalentsMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMember2022-03-310001321741Nth Degree Investment Group, LLC – Common Stock2022-03-310001321741gain:CommonEquityEquivalentsMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:PersonalAndNonDurableConsumerProductsManufacturingOnlyMember2022-03-310001321741The Mountain Corporation – Common Stock2022-03-310001321741gain:CommonEquityEquivalentsMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMembergain:TelecommunicationsMember2022-03-310001321741B+T Group Acquisition, Inc. – Common Stock Warrants2022-03-310001321741gain:PreferredEquityMemberus-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2022-03-310001321741gain:BuildingsAndRealEstateMembergain:PreferredEquityMemberus-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2022-03-310001321741gain:CommonEquityEquivalentsMembergain:LeisureAmusementMotionPicturesAndEntertainmentMemberus-gaap-supplement:InvestmentAffiliatedIssuerControlledMemberGladstone SOG Investments, Inc. - Common Stock2022-03-310001321741gain:CommonEquityEquivalentsMembergain:LeisureAmusementMotionPicturesAndEntertainmentMemberGladstone SOG Investments, Inc. - Common Stock2022-03-310001321741gain:CommonEquityEquivalentsMemberus-gaap-supplement:InvestmentAffiliatedIssuerControlledMember2022-03-310001321741us-gaap:CollateralPledgedMember2022-03-310001321741gain:FunkoAcquisitionHoldingsLLCMember2022-03-310001321741J.R. Hobbs Co. and The Mountain Corporationus-gaap:DebtSecuritiesMember2022-09-300001321741J.R. Hobbs, The Mountain, and SFEG Holdings, Inc.us-gaap:DebtSecuritiesMember2022-03-310001321741gain:DebtSecuritiesSecuredFirstLienDebtMember2022-09-300001321741us-gaap:FairValueInputsLevel1Membergain:DebtSecuritiesSecuredFirstLienDebtMember2022-09-300001321741gain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel2Member2022-09-300001321741gain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741gain:DebtSecuritiesSecuredSecondLienDebtMember2022-09-300001321741us-gaap:FairValueInputsLevel1Membergain:DebtSecuritiesSecuredSecondLienDebtMember2022-09-300001321741gain:DebtSecuritiesSecuredSecondLienDebtMemberus-gaap:FairValueInputsLevel2Member2022-09-300001321741us-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMember2022-09-300001321741gain:PreferredEquityMember2022-09-300001321741gain:PreferredEquityMemberus-gaap:FairValueInputsLevel1Member2022-09-300001321741gain:PreferredEquityMemberus-gaap:FairValueInputsLevel2Member2022-09-300001321741gain:PreferredEquityMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741gain:CommonEquityEquivalentsMember2022-09-300001321741gain:CommonEquityEquivalentsMemberus-gaap:FairValueInputsLevel1Member2022-09-300001321741gain:CommonEquityEquivalentsMemberus-gaap:FairValueInputsLevel2Member2022-09-300001321741gain:CommonEquityEquivalentsMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741us-gaap:FairValueInputsLevel1Member2022-09-300001321741us-gaap:FairValueInputsLevel2Member2022-09-300001321741us-gaap:FairValueInputsLevel3Member2022-09-300001321741gain:DebtSecuritiesSecuredFirstLienDebtMember2022-03-310001321741us-gaap:FairValueInputsLevel1Membergain:DebtSecuritiesSecuredFirstLienDebtMember2022-03-310001321741gain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel2Member2022-03-310001321741gain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741gain:DebtSecuritiesSecuredSecondLienDebtMember2022-03-310001321741us-gaap:FairValueInputsLevel1Membergain:DebtSecuritiesSecuredSecondLienDebtMember2022-03-310001321741gain:DebtSecuritiesSecuredSecondLienDebtMemberus-gaap:FairValueInputsLevel2Member2022-03-310001321741us-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMember2022-03-310001321741gain:PreferredEquityMember2022-03-310001321741gain:PreferredEquityMemberus-gaap:FairValueInputsLevel1Member2022-03-310001321741gain:PreferredEquityMemberus-gaap:FairValueInputsLevel2Member2022-03-310001321741gain:PreferredEquityMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741gain:CommonEquityEquivalentsMember2022-03-310001321741gain:CommonEquityEquivalentsMemberus-gaap:FairValueInputsLevel1Member2022-03-310001321741gain:CommonEquityEquivalentsMemberus-gaap:FairValueInputsLevel2Member2022-03-310001321741gain:CommonEquityEquivalentsMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741us-gaap:FairValueInputsLevel1Member2022-03-310001321741us-gaap:FairValueInputsLevel2Member2022-03-310001321741us-gaap:FairValueInputsLevel3Member2022-03-310001321741us-gaap:FairValueMeasurementsRecurringMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741us-gaap:FairValueMeasurementsRecurringMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741us-gaap:FairValueMeasurementsRecurringMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMember2022-09-300001321741us-gaap:FairValueMeasurementsRecurringMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMember2022-03-310001321741us-gaap:FairValueMeasurementsRecurringMembergain:PreferredEquityMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741us-gaap:FairValueMeasurementsRecurringMembergain:PreferredEquityMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741gain:CommonEquityEquivalentsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741gain:CommonEquityEquivalentsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741us-gaap:FairValueMeasurementsRecurringMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741us-gaap:FairValueMeasurementsRecurringMemberus-gaap-supplement:InvestmentUnaffiliatedIssuerMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMemberus-gaap:FairValueMeasurementsRecurringMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMemberus-gaap:FairValueMeasurementsRecurringMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMember2022-09-300001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMember2022-03-310001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMemberus-gaap:FairValueMeasurementsRecurringMembergain:PreferredEquityMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMemberus-gaap:FairValueMeasurementsRecurringMembergain:PreferredEquityMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741gain:CommonEquityEquivalentsMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741gain:CommonEquityEquivalentsMemberus-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741us-gaap-supplement:InvestmentAffiliatedIssuerNoncontrolledMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741us-gaap:FairValueMeasurementsRecurringMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap-supplement:InvestmentAffiliatedIssuerControlledMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741us-gaap:FairValueMeasurementsRecurringMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap-supplement:InvestmentAffiliatedIssuerControlledMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741us-gaap:FairValueMeasurementsRecurringMemberus-gaap-supplement:InvestmentAffiliatedIssuerControlledMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMember2022-09-300001321741us-gaap:FairValueMeasurementsRecurringMemberus-gaap-supplement:InvestmentAffiliatedIssuerControlledMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMember2022-03-310001321741us-gaap:FairValueMeasurementsRecurringMembergain:PreferredEquityMemberus-gaap-supplement:InvestmentAffiliatedIssuerControlledMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741us-gaap:FairValueMeasurementsRecurringMembergain:PreferredEquityMemberus-gaap-supplement:InvestmentAffiliatedIssuerControlledMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741gain:CommonEquityEquivalentsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap-supplement:InvestmentAffiliatedIssuerControlledMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741gain:CommonEquityEquivalentsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap-supplement:InvestmentAffiliatedIssuerControlledMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741us-gaap:FairValueMeasurementsRecurringMemberus-gaap-supplement:InvestmentAffiliatedIssuerControlledMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741us-gaap:FairValueMeasurementsRecurringMemberus-gaap-supplement:InvestmentAffiliatedIssuerControlledMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741gain:CommonEquityEquivalentsMemberFunko Acquisition Holdings, LLCus-gaap:FairValueInputsLevel2Member2022-09-300001321741gain:CommonEquityEquivalentsMemberFunko Acquisition Holdings, LLCus-gaap:FairValueInputsLevel2Member2022-03-310001321741gain:TotalEnterpriseValueMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741gain:TotalEnterpriseValueMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741gain:TotalEnterpriseValueMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMemberus-gaap:MeasurementInputEbitdaMultipleMember2022-09-300001321741gain:TotalEnterpriseValueMembersrt:MaximumMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputEbitdaMultipleMember2022-09-300001321741gain:TotalEnterpriseValueMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:MeasurementInputEbitdaMultipleMember2022-09-300001321741gain:TotalEnterpriseValueMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMemberus-gaap:MeasurementInputEbitdaMultipleMember2022-03-310001321741gain:TotalEnterpriseValueMembersrt:MaximumMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputEbitdaMultipleMember2022-03-310001321741gain:TotalEnterpriseValueMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:MeasurementInputEbitdaMultipleMember2022-03-310001321741gain:TotalEnterpriseValueMembergain:MeasurementInputEBITDAMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMember2022-09-300001321741gain:TotalEnterpriseValueMembersrt:MaximumMembergain:MeasurementInputEBITDAMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741gain:TotalEnterpriseValueMembergain:MeasurementInputEBITDAMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMember2022-09-300001321741gain:TotalEnterpriseValueMembergain:MeasurementInputEBITDAMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMember2022-03-310001321741gain:TotalEnterpriseValueMembersrt:MaximumMembergain:MeasurementInputEBITDAMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741gain:TotalEnterpriseValueMembergain:MeasurementInputEBITDAMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMember2022-03-310001321741gain:TotalEnterpriseValueMemberus-gaap:MeasurementInputRevenueMultipleMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMember2022-09-300001321741gain:TotalEnterpriseValueMembersrt:MaximumMemberus-gaap:MeasurementInputRevenueMultipleMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741gain:TotalEnterpriseValueMemberus-gaap:MeasurementInputRevenueMultipleMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMember2022-09-300001321741gain:TotalEnterpriseValueMemberus-gaap:MeasurementInputRevenueMultipleMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMember2022-03-310001321741gain:TotalEnterpriseValueMembersrt:MaximumMemberus-gaap:MeasurementInputRevenueMultipleMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741gain:TotalEnterpriseValueMemberus-gaap:MeasurementInputRevenueMultipleMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMember2022-03-310001321741gain:TotalEnterpriseValueMembergain:MeasurementInputRevenueMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMember2022-09-300001321741gain:TotalEnterpriseValueMembersrt:MaximumMembergain:MeasurementInputRevenueMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741gain:TotalEnterpriseValueMembergain:MeasurementInputRevenueMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMember2022-09-300001321741gain:TotalEnterpriseValueMembergain:MeasurementInputRevenueMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMember2022-03-310001321741gain:TotalEnterpriseValueMembersrt:MaximumMembergain:MeasurementInputRevenueMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741gain:TotalEnterpriseValueMembergain:MeasurementInputRevenueMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMember2022-03-310001321741gain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Membergain:YieldAnalysisMember2022-09-300001321741gain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Membergain:YieldAnalysisMember2022-03-310001321741us-gaap:MeasurementInputDiscountRateMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Membergain:YieldAnalysisMembersrt:MinimumMember2022-09-300001321741srt:MaximumMemberus-gaap:MeasurementInputDiscountRateMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Membergain:YieldAnalysisMember2022-09-300001321741us-gaap:MeasurementInputDiscountRateMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Membergain:YieldAnalysisMembersrt:WeightedAverageMember2022-09-300001321741us-gaap:MeasurementInputDiscountRateMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Membergain:YieldAnalysisMembersrt:MinimumMember2022-03-310001321741srt:MaximumMemberus-gaap:MeasurementInputDiscountRateMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Membergain:YieldAnalysisMember2022-03-310001321741us-gaap:MeasurementInputDiscountRateMembergain:DebtSecuritiesSecuredFirstLienDebtMemberus-gaap:FairValueInputsLevel3Membergain:YieldAnalysisMembersrt:WeightedAverageMember2022-03-310001321741gain:TotalEnterpriseValueMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMember2022-09-300001321741gain:TotalEnterpriseValueMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMember2022-03-310001321741gain:TotalEnterpriseValueMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMembersrt:MinimumMemberus-gaap:MeasurementInputEbitdaMultipleMember2022-09-300001321741gain:TotalEnterpriseValueMembersrt:MaximumMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMemberus-gaap:MeasurementInputEbitdaMultipleMember2022-09-300001321741gain:TotalEnterpriseValueMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMembersrt:WeightedAverageMemberus-gaap:MeasurementInputEbitdaMultipleMember2022-09-300001321741gain:TotalEnterpriseValueMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMembersrt:MinimumMemberus-gaap:MeasurementInputEbitdaMultipleMember2022-03-310001321741gain:TotalEnterpriseValueMembersrt:MaximumMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMemberus-gaap:MeasurementInputEbitdaMultipleMember2022-03-310001321741gain:TotalEnterpriseValueMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMembersrt:WeightedAverageMemberus-gaap:MeasurementInputEbitdaMultipleMember2022-03-310001321741gain:TotalEnterpriseValueMembergain:MeasurementInputEBITDAMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMembersrt:MinimumMember2022-09-300001321741gain:TotalEnterpriseValueMembersrt:MaximumMembergain:MeasurementInputEBITDAMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMember2022-09-300001321741gain:TotalEnterpriseValueMembergain:MeasurementInputEBITDAMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMembersrt:WeightedAverageMember2022-09-300001321741gain:TotalEnterpriseValueMembergain:MeasurementInputEBITDAMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMembersrt:MinimumMember2022-03-310001321741gain:TotalEnterpriseValueMembersrt:MaximumMembergain:MeasurementInputEBITDAMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMember2022-03-310001321741gain:TotalEnterpriseValueMembergain:MeasurementInputEBITDAMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMembersrt:WeightedAverageMember2022-03-310001321741gain:TotalEnterpriseValueMemberus-gaap:MeasurementInputRevenueMultipleMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMembersrt:MinimumMember2022-09-300001321741gain:TotalEnterpriseValueMembersrt:MaximumMemberus-gaap:MeasurementInputRevenueMultipleMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMember2022-09-300001321741gain:TotalEnterpriseValueMemberus-gaap:MeasurementInputRevenueMultipleMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMembersrt:WeightedAverageMember2022-09-300001321741gain:TotalEnterpriseValueMemberus-gaap:MeasurementInputRevenueMultipleMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMembersrt:MinimumMember2022-03-310001321741gain:TotalEnterpriseValueMembersrt:MaximumMemberus-gaap:MeasurementInputRevenueMultipleMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMember2022-03-310001321741gain:TotalEnterpriseValueMemberus-gaap:MeasurementInputRevenueMultipleMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMembersrt:WeightedAverageMember2022-03-310001321741gain:TotalEnterpriseValueMembergain:MeasurementInputRevenueMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMembersrt:MinimumMember2022-09-300001321741gain:TotalEnterpriseValueMembersrt:MaximumMembergain:MeasurementInputRevenueMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMember2022-09-300001321741gain:TotalEnterpriseValueMembergain:MeasurementInputRevenueMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMembersrt:WeightedAverageMember2022-09-300001321741gain:TotalEnterpriseValueMembergain:MeasurementInputRevenueMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMembersrt:MinimumMember2022-03-310001321741gain:TotalEnterpriseValueMembersrt:MaximumMembergain:MeasurementInputRevenueMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMember2022-03-310001321741gain:TotalEnterpriseValueMembergain:MeasurementInputRevenueMemberus-gaap:FairValueInputsLevel3Membergain:DebtSecuritiesSecuredSecondLienDebtMembersrt:WeightedAverageMember2022-03-310001321741us-gaap:FairValueInputsLevel3Membergain:YieldAnalysisMembergain:DebtSecuritiesSecuredSecondLienDebtMember2022-09-300001321741us-gaap:FairValueInputsLevel3Membergain:YieldAnalysisMembergain:DebtSecuritiesSecuredSecondLienDebtMember2022-03-310001321741us-gaap:MeasurementInputDiscountRateMemberus-gaap:FairValueInputsLevel3Membergain:YieldAnalysisMembergain:DebtSecuritiesSecuredSecondLienDebtMembersrt:MinimumMember2022-09-300001321741srt:MaximumMemberus-gaap:MeasurementInputDiscountRateMemberus-gaap:FairValueInputsLevel3Membergain:YieldAnalysisMembergain:DebtSecuritiesSecuredSecondLienDebtMember2022-09-300001321741us-gaap:MeasurementInputDiscountRateMemberus-gaap:FairValueInputsLevel3Membergain:YieldAnalysisMembergain:DebtSecuritiesSecuredSecondLienDebtMembersrt:WeightedAverageMember2022-09-300001321741us-gaap:MeasurementInputDiscountRateMemberus-gaap:FairValueInputsLevel3Membergain:YieldAnalysisMembergain:DebtSecuritiesSecuredSecondLienDebtMembersrt:MinimumMember2022-03-310001321741srt:MaximumMemberus-gaap:MeasurementInputDiscountRateMemberus-gaap:FairValueInputsLevel3Membergain:YieldAnalysisMembergain:DebtSecuritiesSecuredSecondLienDebtMember2022-03-310001321741us-gaap:MeasurementInputDiscountRateMemberus-gaap:FairValueInputsLevel3Membergain:YieldAnalysisMembergain:DebtSecuritiesSecuredSecondLienDebtMembersrt:WeightedAverageMember2022-03-310001321741gain:TotalEnterpriseValueMembergain:PreferredEquityMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741gain:TotalEnterpriseValueMembergain:PreferredEquityMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741gain:TotalEnterpriseValueMembergain:PreferredEquityMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMemberus-gaap:MeasurementInputEbitdaMultipleMember2022-09-300001321741gain:TotalEnterpriseValueMembersrt:MaximumMembergain:PreferredEquityMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputEbitdaMultipleMember2022-09-300001321741gain:TotalEnterpriseValueMembergain:PreferredEquityMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:MeasurementInputEbitdaMultipleMember2022-09-300001321741gain:TotalEnterpriseValueMembergain:PreferredEquityMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMemberus-gaap:MeasurementInputEbitdaMultipleMember2022-03-310001321741gain:TotalEnterpriseValueMembersrt:MaximumMembergain:PreferredEquityMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputEbitdaMultipleMember2022-03-310001321741gain:TotalEnterpriseValueMembergain:PreferredEquityMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:MeasurementInputEbitdaMultipleMember2022-03-310001321741gain:TotalEnterpriseValueMembergain:MeasurementInputEBITDAMembergain:PreferredEquityMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMember2022-09-300001321741gain:TotalEnterpriseValueMembersrt:MaximumMembergain:MeasurementInputEBITDAMembergain:PreferredEquityMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741gain:TotalEnterpriseValueMembergain:MeasurementInputEBITDAMembergain:PreferredEquityMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMember2022-09-300001321741gain:TotalEnterpriseValueMembergain:MeasurementInputEBITDAMembergain:PreferredEquityMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMember2022-03-310001321741gain:TotalEnterpriseValueMembersrt:MaximumMembergain:MeasurementInputEBITDAMembergain:PreferredEquityMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741gain:TotalEnterpriseValueMembergain:MeasurementInputEBITDAMembergain:PreferredEquityMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMember2022-03-310001321741gain:TotalEnterpriseValueMembergain:PreferredEquityMemberus-gaap:MeasurementInputRevenueMultipleMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMember2022-09-300001321741gain:TotalEnterpriseValueMembersrt:MaximumMembergain:PreferredEquityMemberus-gaap:MeasurementInputRevenueMultipleMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741gain:TotalEnterpriseValueMembergain:PreferredEquityMemberus-gaap:MeasurementInputRevenueMultipleMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMember2022-09-300001321741gain:TotalEnterpriseValueMembergain:PreferredEquityMemberus-gaap:MeasurementInputRevenueMultipleMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMember2022-03-310001321741gain:TotalEnterpriseValueMembersrt:MaximumMembergain:PreferredEquityMemberus-gaap:MeasurementInputRevenueMultipleMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741gain:TotalEnterpriseValueMembergain:PreferredEquityMemberus-gaap:MeasurementInputRevenueMultipleMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMember2022-03-310001321741gain:TotalEnterpriseValueMembergain:MeasurementInputRevenueMembergain:PreferredEquityMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMember2022-09-300001321741gain:TotalEnterpriseValueMembersrt:MaximumMembergain:MeasurementInputRevenueMembergain:PreferredEquityMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741gain:TotalEnterpriseValueMembergain:MeasurementInputRevenueMembergain:PreferredEquityMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMember2022-09-300001321741gain:TotalEnterpriseValueMembergain:MeasurementInputRevenueMembergain:PreferredEquityMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMember2022-03-310001321741gain:TotalEnterpriseValueMembersrt:MaximumMembergain:MeasurementInputRevenueMembergain:PreferredEquityMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741gain:TotalEnterpriseValueMembergain:MeasurementInputRevenueMembergain:PreferredEquityMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMember2022-03-310001321741gain:TotalEnterpriseValueMembergain:CommonEquityEquivalentsMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741gain:TotalEnterpriseValueMembergain:CommonEquityEquivalentsMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741gain:TotalEnterpriseValueMembergain:CommonEquityEquivalentsMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMemberus-gaap:MeasurementInputEbitdaMultipleMember2022-09-300001321741gain:TotalEnterpriseValueMembergain:CommonEquityEquivalentsMembersrt:MaximumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputEbitdaMultipleMember2022-09-300001321741gain:TotalEnterpriseValueMembergain:CommonEquityEquivalentsMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:MeasurementInputEbitdaMultipleMember2022-09-300001321741gain:TotalEnterpriseValueMembergain:CommonEquityEquivalentsMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMemberus-gaap:MeasurementInputEbitdaMultipleMember2022-03-310001321741gain:TotalEnterpriseValueMembergain:CommonEquityEquivalentsMembersrt:MaximumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputEbitdaMultipleMember2022-03-310001321741gain:TotalEnterpriseValueMembergain:CommonEquityEquivalentsMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:MeasurementInputEbitdaMultipleMember2022-03-310001321741gain:TotalEnterpriseValueMembergain:CommonEquityEquivalentsMembergain:MeasurementInputEBITDAMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMember2022-09-300001321741gain:TotalEnterpriseValueMembergain:CommonEquityEquivalentsMembersrt:MaximumMembergain:MeasurementInputEBITDAMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741gain:TotalEnterpriseValueMembergain:CommonEquityEquivalentsMembergain:MeasurementInputEBITDAMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMember2022-09-300001321741gain:TotalEnterpriseValueMembergain:CommonEquityEquivalentsMembergain:MeasurementInputEBITDAMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMember2022-03-310001321741gain:TotalEnterpriseValueMembergain:CommonEquityEquivalentsMembersrt:MaximumMembergain:MeasurementInputEBITDAMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741gain:TotalEnterpriseValueMembergain:CommonEquityEquivalentsMembergain:MeasurementInputEBITDAMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMember2022-03-310001321741gain:TotalEnterpriseValueMembergain:CommonEquityEquivalentsMemberus-gaap:MeasurementInputRevenueMultipleMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMember2022-09-300001321741gain:TotalEnterpriseValueMembergain:CommonEquityEquivalentsMembersrt:MaximumMemberus-gaap:MeasurementInputRevenueMultipleMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741gain:TotalEnterpriseValueMembergain:CommonEquityEquivalentsMemberus-gaap:MeasurementInputRevenueMultipleMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMember2022-09-300001321741gain:TotalEnterpriseValueMembergain:CommonEquityEquivalentsMemberus-gaap:MeasurementInputRevenueMultipleMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMember2022-03-310001321741gain:TotalEnterpriseValueMembergain:CommonEquityEquivalentsMembersrt:MaximumMemberus-gaap:MeasurementInputRevenueMultipleMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741gain:TotalEnterpriseValueMembergain:CommonEquityEquivalentsMemberus-gaap:MeasurementInputRevenueMultipleMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMember2022-03-310001321741gain:TotalEnterpriseValueMembergain:CommonEquityEquivalentsMembergain:MeasurementInputRevenueMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMember2022-09-300001321741gain:TotalEnterpriseValueMembergain:CommonEquityEquivalentsMembersrt:MaximumMembergain:MeasurementInputRevenueMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741gain:TotalEnterpriseValueMembergain:CommonEquityEquivalentsMembergain:MeasurementInputRevenueMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMember2022-09-300001321741gain:TotalEnterpriseValueMembergain:CommonEquityEquivalentsMembergain:MeasurementInputRevenueMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMember2022-03-310001321741gain:TotalEnterpriseValueMembergain:CommonEquityEquivalentsMembersrt:MaximumMembergain:MeasurementInputRevenueMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741gain:TotalEnterpriseValueMembergain:CommonEquityEquivalentsMembergain:MeasurementInputRevenueMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMember2022-03-310001321741gain:DebtSecuritiesSecuredFirstLienDebtMember2022-06-300001321741gain:DebtSecuritiesSecuredSecondLienDebtMember2022-06-300001321741gain:PreferredEquityMember2022-06-300001321741gain:CommonEquityEquivalentsMember2022-06-300001321741us-gaap:InvestmentsMember2022-06-300001321741gain:DebtAndEquitySecuritiesRealizedGainLossMembergain:DebtSecuritiesSecuredFirstLienDebtMember2022-07-012022-09-300001321741gain:DebtAndEquitySecuritiesRealizedGainLossMembergain:DebtSecuritiesSecuredSecondLienDebtMember2022-07-012022-09-300001321741gain:PreferredEquityMembergain:DebtAndEquitySecuritiesRealizedGainLossMember2022-07-012022-09-300001321741gain:DebtAndEquitySecuritiesRealizedGainLossMembergain:CommonEquityEquivalentsMember2022-07-012022-09-300001321741gain:DebtAndEquitySecuritiesRealizedGainLossMemberus-gaap:InvestmentsMember2022-07-012022-09-300001321741gain:DebtAndEquitySecuritiesUnrealizedGainLossMembergain:DebtSecuritiesSecuredFirstLienDebtMember2022-07-012022-09-300001321741gain:DebtAndEquitySecuritiesUnrealizedGainLossMembergain:DebtSecuritiesSecuredSecondLienDebtMember2022-07-012022-09-300001321741gain:PreferredEquityMembergain:DebtAndEquitySecuritiesUnrealizedGainLossMember2022-07-012022-09-300001321741gain:CommonEquityEquivalentsMembergain:DebtAndEquitySecuritiesUnrealizedGainLossMember2022-07-012022-09-300001321741gain:DebtAndEquitySecuritiesUnrealizedGainLossMemberus-gaap:InvestmentsMember2022-07-012022-09-300001321741gain:DebtSecuritiesSecuredFirstLienDebtMember2022-07-012022-09-300001321741gain:DebtSecuritiesSecuredSecondLienDebtMember2022-07-012022-09-300001321741gain:PreferredEquityMember2022-07-012022-09-300001321741gain:CommonEquityEquivalentsMember2022-07-012022-09-300001321741us-gaap:InvestmentsMember2022-07-012022-09-300001321741gain:DebtSecuritiesSecuredFirstLienDebtMember2022-09-300001321741gain:DebtSecuritiesSecuredSecondLienDebtMember2022-09-300001321741gain:PreferredEquityMember2022-09-300001321741gain:CommonEquityEquivalentsMember2022-09-300001321741us-gaap:InvestmentsMember2022-09-300001321741gain:DebtSecuritiesSecuredFirstLienDebtMember2022-03-310001321741gain:DebtSecuritiesSecuredSecondLienDebtMember2022-03-310001321741gain:PreferredEquityMember2022-03-310001321741gain:CommonEquityEquivalentsMember2022-03-310001321741us-gaap:InvestmentsMember2022-03-310001321741gain:DebtAndEquitySecuritiesRealizedGainLossMembergain:DebtSecuritiesSecuredFirstLienDebtMember2022-04-012022-09-300001321741gain:DebtAndEquitySecuritiesRealizedGainLossMembergain:DebtSecuritiesSecuredSecondLienDebtMember2022-04-012022-09-300001321741gain:PreferredEquityMembergain:DebtAndEquitySecuritiesRealizedGainLossMember2022-04-012022-09-300001321741gain:DebtAndEquitySecuritiesRealizedGainLossMembergain:CommonEquityEquivalentsMember2022-04-012022-09-300001321741gain:DebtAndEquitySecuritiesRealizedGainLossMemberus-gaap:InvestmentsMember2022-04-012022-09-300001321741gain:DebtAndEquitySecuritiesUnrealizedGainLossMembergain:DebtSecuritiesSecuredFirstLienDebtMember2022-04-012022-09-300001321741gain:DebtAndEquitySecuritiesUnrealizedGainLossMembergain:DebtSecuritiesSecuredSecondLienDebtMember2022-04-012022-09-300001321741gain:PreferredEquityMembergain:DebtAndEquitySecuritiesUnrealizedGainLossMember2022-04-012022-09-300001321741gain:CommonEquityEquivalentsMembergain:DebtAndEquitySecuritiesUnrealizedGainLossMember2022-04-012022-09-300001321741gain:DebtAndEquitySecuritiesUnrealizedGainLossMemberus-gaap:InvestmentsMember2022-04-012022-09-300001321741gain:DebtSecuritiesSecuredFirstLienDebtMember2022-04-012022-09-300001321741gain:DebtSecuritiesSecuredSecondLienDebtMember2022-04-012022-09-300001321741gain:PreferredEquityMember2022-04-012022-09-300001321741gain:CommonEquityEquivalentsMember2022-04-012022-09-300001321741us-gaap:InvestmentsMember2022-04-012022-09-300001321741gain:DebtSecuritiesSecuredFirstLienDebtMember2021-06-300001321741gain:DebtSecuritiesSecuredSecondLienDebtMember2021-06-300001321741gain:PreferredEquityMember2021-06-300001321741gain:CommonEquityEquivalentsMember2021-06-300001321741us-gaap:InvestmentsMember2021-06-300001321741gain:DebtAndEquitySecuritiesRealizedGainLossMembergain:DebtSecuritiesSecuredFirstLienDebtMember2021-07-012021-09-300001321741gain:DebtAndEquitySecuritiesRealizedGainLossMembergain:DebtSecuritiesSecuredSecondLienDebtMember2021-07-012021-09-300001321741gain:PreferredEquityMembergain:DebtAndEquitySecuritiesRealizedGainLossMember2021-07-012021-09-300001321741gain:DebtAndEquitySecuritiesRealizedGainLossMembergain:CommonEquityEquivalentsMember2021-07-012021-09-300001321741gain:DebtAndEquitySecuritiesRealizedGainLossMemberus-gaap:InvestmentsMember2021-07-012021-09-300001321741gain:DebtAndEquitySecuritiesUnrealizedGainLossMembergain:DebtSecuritiesSecuredFirstLienDebtMember2021-07-012021-09-300001321741gain:DebtAndEquitySecuritiesUnrealizedGainLossMembergain:DebtSecuritiesSecuredSecondLienDebtMember2021-07-012021-09-300001321741gain:PreferredEquityMembergain:DebtAndEquitySecuritiesUnrealizedGainLossMember2021-07-012021-09-300001321741gain:CommonEquityEquivalentsMembergain:DebtAndEquitySecuritiesUnrealizedGainLossMember2021-07-012021-09-300001321741gain:DebtAndEquitySecuritiesUnrealizedGainLossMemberus-gaap:InvestmentsMember2021-07-012021-09-300001321741gain:DebtSecuritiesSecuredFirstLienDebtMember2021-07-012021-09-300001321741gain:DebtSecuritiesSecuredSecondLienDebtMember2021-07-012021-09-300001321741gain:PreferredEquityMember2021-07-012021-09-300001321741gain:CommonEquityEquivalentsMember2021-07-012021-09-300001321741us-gaap:InvestmentsMember2021-07-012021-09-300001321741gain:DebtSecuritiesSecuredFirstLienDebtMember2021-09-300001321741gain:DebtSecuritiesSecuredSecondLienDebtMember2021-09-300001321741gain:PreferredEquityMember2021-09-300001321741gain:CommonEquityEquivalentsMember2021-09-300001321741us-gaap:InvestmentsMember2021-09-300001321741gain:DebtSecuritiesSecuredFirstLienDebtMember2021-03-310001321741gain:DebtSecuritiesSecuredSecondLienDebtMember2021-03-310001321741gain:PreferredEquityMember2021-03-310001321741gain:CommonEquityEquivalentsMember2021-03-310001321741us-gaap:InvestmentsMember2021-03-310001321741gain:DebtAndEquitySecuritiesRealizedGainLossMembergain:DebtSecuritiesSecuredFirstLienDebtMember2021-04-012021-09-300001321741gain:DebtAndEquitySecuritiesRealizedGainLossMembergain:DebtSecuritiesSecuredSecondLienDebtMember2021-04-012021-09-300001321741gain:PreferredEquityMembergain:DebtAndEquitySecuritiesRealizedGainLossMember2021-04-012021-09-300001321741gain:DebtAndEquitySecuritiesRealizedGainLossMembergain:CommonEquityEquivalentsMember2021-04-012021-09-300001321741gain:DebtAndEquitySecuritiesRealizedGainLossMemberus-gaap:InvestmentsMember2021-04-012021-09-300001321741gain:DebtAndEquitySecuritiesUnrealizedGainLossMembergain:DebtSecuritiesSecuredFirstLienDebtMember2021-04-012021-09-300001321741gain:DebtAndEquitySecuritiesUnrealizedGainLossMembergain:DebtSecuritiesSecuredSecondLienDebtMember2021-04-012021-09-300001321741gain:PreferredEquityMembergain:DebtAndEquitySecuritiesUnrealizedGainLossMember2021-04-012021-09-300001321741gain:CommonEquityEquivalentsMembergain:DebtAndEquitySecuritiesUnrealizedGainLossMember2021-04-012021-09-300001321741gain:DebtAndEquitySecuritiesUnrealizedGainLossMemberus-gaap:InvestmentsMember2021-04-012021-09-300001321741gain:DebtSecuritiesSecuredFirstLienDebtMember2021-04-012021-09-300001321741gain:DebtSecuritiesSecuredSecondLienDebtMember2021-04-012021-09-300001321741gain:PreferredEquityMember2021-04-012021-09-300001321741gain:CommonEquityEquivalentsMember2021-04-012021-09-300001321741us-gaap:InvestmentsMember2021-04-012021-09-300001321741Horizon Facilities Services, Inc.gain:PreferredEquityMember2022-09-300001321741Ginsey Home Solutions, Inc.gain:DebtSecuritiesSecuredSecondLienDebtMember2022-09-300001321741PSI Molded Plastics, Inc.gain:DebtSecuritiesSecuredFirstLienDebtMember2022-09-300001321741J.R. Hobbs Co. - Atlanta, LLCgain:DebtSecuritiesSecuredSecondLienDebtMember2021-09-300001321741D.P.M.S., Inc.gain:DebtSecuritiesSecuredSecondLienDebtMember2021-09-300001321741gain:PreferredEquityMemberGalaxy Technologies, Inc.2021-09-300001321741gain:DebtSecuritiesSecuredFirstLienDebtMemberNocturne Villa Rentals, Inc.2022-05-012022-05-310001321741Bassett Creek Services, Inc.2022-06-012022-06-300001321741Dema/Mai Holdings, Inc.2022-06-012022-06-300001321741Dema/Mai Holdings, Inc.2022-07-012022-07-310001321741Horizon Facilities Services, Inc.gain:DebtSecuritiesSecuredFirstLienDebtMember2022-07-012022-07-310001321741Horizon Facilities Services, Inc.gain:PreferredEquityMember2022-07-012022-07-310001321741Horizon Facilities Services, Inc.gain:PreferredEquityMember2022-07-310001321741Ginsey Home Solutions, Inc.gain:DebtSecuritiesSecuredFirstLienDebtMember2022-08-31gain:portfolioCompanygain:stategain:industry0001321741gain:InvestmentPortfolioBenchmarkMembergain:FiveLargestPortfolioInvestmentsMemberus-gaap:CustomerConcentrationRiskMember2022-09-300001321741gain:InvestmentPortfolioBenchmarkMembergain:FiveLargestPortfolioInvestmentsMemberus-gaap:CustomerConcentrationRiskMember2022-04-012022-09-300001321741gain:DebtSecuritiesSecuredFirstLienDebtMember2022-09-300001321741gain:DebtSecuritiesSecuredFirstLienDebtMembergain:InvestmentTypeConcentrationRiskMembergain:InvestmentOwnedAtCostMember2022-04-012022-09-300001321741gain:DebtSecuritiesSecuredFirstLienDebtMembergain:InvestmentTypeConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2022-04-012022-09-300001321741gain:DebtSecuritiesSecuredFirstLienDebtMember2022-03-310001321741gain:DebtSecuritiesSecuredFirstLienDebtMembergain:InvestmentTypeConcentrationRiskMembergain:InvestmentOwnedAtCostMember2021-04-012022-03-310001321741gain:DebtSecuritiesSecuredFirstLienDebtMembergain:InvestmentTypeConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2021-04-012022-03-310001321741gain:DebtSecuritiesSecuredSecondLienDebtMember2022-09-300001321741gain:InvestmentTypeConcentrationRiskMembergain:DebtSecuritiesSecuredSecondLienDebtMembergain:InvestmentOwnedAtCostMember2022-04-012022-09-300001321741gain:InvestmentTypeConcentrationRiskMembergain:DebtSecuritiesSecuredSecondLienDebtMembergain:InvestmentOwnedAtFairValueMember2022-04-012022-09-300001321741gain:DebtSecuritiesSecuredSecondLienDebtMember2022-03-310001321741gain:InvestmentTypeConcentrationRiskMembergain:DebtSecuritiesSecuredSecondLienDebtMembergain:InvestmentOwnedAtCostMember2021-04-012022-03-310001321741gain:InvestmentTypeConcentrationRiskMembergain:DebtSecuritiesSecuredSecondLienDebtMembergain:InvestmentOwnedAtFairValueMember2021-04-012022-03-310001321741us-gaap:DebtSecuritiesMember2022-09-300001321741gain:InvestmentTypeConcentrationRiskMembergain:InvestmentOwnedAtCostMemberus-gaap:DebtSecuritiesMember2022-04-012022-09-300001321741gain:InvestmentTypeConcentrationRiskMembergain:InvestmentOwnedAtFairValueMemberus-gaap:DebtSecuritiesMember2022-04-012022-09-300001321741us-gaap:DebtSecuritiesMember2022-03-310001321741gain:InvestmentTypeConcentrationRiskMembergain:InvestmentOwnedAtCostMemberus-gaap:DebtSecuritiesMember2021-04-012022-03-310001321741gain:InvestmentTypeConcentrationRiskMembergain:InvestmentOwnedAtFairValueMemberus-gaap:DebtSecuritiesMember2021-04-012022-03-310001321741gain:PreferredEquityMember2022-09-300001321741gain:PreferredEquityMembergain:InvestmentTypeConcentrationRiskMembergain:InvestmentOwnedAtCostMember2022-04-012022-09-300001321741gain:PreferredEquityMembergain:InvestmentTypeConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2022-04-012022-09-300001321741gain:PreferredEquityMember2022-03-310001321741gain:PreferredEquityMembergain:InvestmentTypeConcentrationRiskMembergain:InvestmentOwnedAtCostMember2021-04-012022-03-310001321741gain:PreferredEquityMembergain:InvestmentTypeConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2021-04-012022-03-310001321741gain:CommonEquityEquivalentsMember2022-09-300001321741gain:CommonEquityEquivalentsMembergain:InvestmentTypeConcentrationRiskMembergain:InvestmentOwnedAtCostMember2022-04-012022-09-300001321741gain:CommonEquityEquivalentsMembergain:InvestmentTypeConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2022-04-012022-09-300001321741gain:CommonEquityEquivalentsMember2022-03-310001321741gain:CommonEquityEquivalentsMembergain:InvestmentTypeConcentrationRiskMembergain:InvestmentOwnedAtCostMember2021-04-012022-03-310001321741gain:CommonEquityEquivalentsMembergain:InvestmentTypeConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2021-04-012022-03-310001321741us-gaap:EquitySecuritiesMember2022-09-300001321741us-gaap:EquitySecuritiesMembergain:InvestmentTypeConcentrationRiskMembergain:InvestmentOwnedAtCostMember2022-04-012022-09-300001321741us-gaap:EquitySecuritiesMembergain:InvestmentTypeConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2022-04-012022-09-300001321741us-gaap:EquitySecuritiesMember2022-03-310001321741us-gaap:EquitySecuritiesMembergain:InvestmentTypeConcentrationRiskMembergain:InvestmentOwnedAtCostMember2021-04-012022-03-310001321741us-gaap:EquitySecuritiesMembergain:InvestmentTypeConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2021-04-012022-03-310001321741gain:InvestmentTypeConcentrationRiskMembergain:InvestmentOwnedAtCostMember2022-04-012022-09-300001321741gain:InvestmentTypeConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2022-04-012022-09-300001321741gain:InvestmentTypeConcentrationRiskMembergain:InvestmentOwnedAtCostMember2021-04-012022-03-310001321741gain:InvestmentTypeConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2021-04-012022-03-310001321741gain:DiversifiedConglomerateServicesMember2022-09-300001321741gain:DiversifiedConglomerateServicesMembergain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2022-04-012022-09-300001321741gain:DiversifiedConglomerateServicesMember2022-03-310001321741gain:DiversifiedConglomerateServicesMembergain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2021-04-012022-03-310001321741gain:HomeAndOfficeFurnishingsHousewaresAndDurableConsumerProductsMember2022-09-300001321741gain:HomeAndOfficeFurnishingsHousewaresAndDurableConsumerProductsMembergain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2022-04-012022-09-300001321741gain:HomeAndOfficeFurnishingsHousewaresAndDurableConsumerProductsMember2022-03-310001321741gain:HomeAndOfficeFurnishingsHousewaresAndDurableConsumerProductsMembergain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2021-04-012022-03-310001321741gain:BuildingsAndRealEstateMember2022-09-300001321741gain:BuildingsAndRealEstateMembergain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2022-04-012022-09-300001321741gain:BuildingsAndRealEstateMember2022-03-310001321741gain:BuildingsAndRealEstateMembergain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2021-04-012022-03-310001321741gain:HotelsMotelsInnsAndGamingTotalMember2022-09-300001321741gain:HotelsMotelsInnsAndGamingTotalMembergain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2022-04-012022-09-300001321741gain:HotelsMotelsInnsAndGamingTotalMember2022-03-310001321741gain:HotelsMotelsInnsAndGamingTotalMembergain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2021-04-012022-03-310001321741gain:LeisureAmusementMotionPicturesAndEntertainmentMember2022-09-300001321741gain:LeisureAmusementMotionPicturesAndEntertainmentMembergain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2022-04-012022-09-300001321741gain:LeisureAmusementMotionPicturesAndEntertainmentMember2022-03-310001321741gain:LeisureAmusementMotionPicturesAndEntertainmentMembergain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2021-04-012022-03-310001321741gain:HealthcareEducationAndChildcareMember2022-09-300001321741gain:HealthcareEducationAndChildcareMembergain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2022-04-012022-09-300001321741gain:HealthcareEducationAndChildcareMember2022-03-310001321741gain:HealthcareEducationAndChildcareMembergain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2021-04-012022-03-310001321741gain:AerospaceAndDefenseMember2022-09-300001321741gain:AerospaceAndDefenseMembergain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2022-04-012022-09-300001321741gain:AerospaceAndDefenseMember2022-03-310001321741gain:AerospaceAndDefenseMembergain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2021-04-012022-03-310001321741gain:ChemicalsPlasticsAndRubberMember2022-09-300001321741gain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMembergain:ChemicalsPlasticsAndRubberMember2022-04-012022-09-300001321741gain:ChemicalsPlasticsAndRubberMember2022-03-310001321741gain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMembergain:ChemicalsPlasticsAndRubberMember2021-04-012022-03-310001321741gain:MiningSteelIronAndNonPreciousMetalsTotalMember2022-09-300001321741gain:MiningSteelIronAndNonPreciousMetalsTotalMembergain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2022-04-012022-09-300001321741gain:MiningSteelIronAndNonPreciousMetalsTotalMember2022-03-310001321741gain:MiningSteelIronAndNonPreciousMetalsTotalMembergain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2021-04-012022-03-310001321741gain:TelecommunicationsMember2022-09-300001321741gain:TelecommunicationsMembergain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2022-04-012022-09-300001321741gain:TelecommunicationsMember2022-03-310001321741gain:TelecommunicationsMembergain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2021-04-012022-03-310001321741gain:MachineryNonAgricultureNonConstructionAndNonElectronicMember2022-09-300001321741gain:MachineryNonAgricultureNonConstructionAndNonElectronicMembergain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2022-04-012022-09-300001321741gain:MachineryNonAgricultureNonConstructionAndNonElectronicMember2022-03-310001321741gain:MachineryNonAgricultureNonConstructionAndNonElectronicMembergain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2021-04-012022-03-310001321741gain:CargoTransportMember2022-09-300001321741gain:CargoTransportMembergain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2022-04-012022-09-300001321741gain:CargoTransportMember2022-03-310001321741gain:CargoTransportMembergain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2021-04-012022-03-310001321741gain:DiversifiedConglomerateManufacturingMember2022-09-300001321741gain:DiversifiedConglomerateManufacturingMembergain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2022-04-012022-09-300001321741gain:DiversifiedConglomerateManufacturingMember2022-03-310001321741gain:DiversifiedConglomerateManufacturingMembergain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2021-04-012022-03-310001321741gain:OtherSectorsMember2022-09-300001321741gain:OtherSectorsMembergain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2022-04-012022-09-300001321741gain:OtherSectorsMember2022-03-310001321741gain:OtherSectorsMembergain:IndustryConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2021-04-012022-03-310001321741gain:InvestmentOwnedAtFairValueMembergain:IndustryConcentrationRiskMember2022-04-012022-09-300001321741gain:InvestmentOwnedAtFairValueMembergain:IndustryConcentrationRiskMember2021-04-012022-03-310001321741us-gaap-supplement:WestRegionMember2022-09-300001321741us-gaap-supplement:WestRegionMembergain:GeographicRegionsConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2022-04-012022-09-300001321741us-gaap-supplement:WestRegionMember2022-03-310001321741us-gaap-supplement:WestRegionMembergain:GeographicRegionsConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2021-04-012022-03-310001321741us-gaap-supplement:NortheastRegionMember2022-09-300001321741us-gaap-supplement:NortheastRegionMembergain:GeographicRegionsConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2022-04-012022-09-300001321741us-gaap-supplement:NortheastRegionMember2022-03-310001321741us-gaap-supplement:NortheastRegionMembergain:GeographicRegionsConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2021-04-012022-03-310001321741us-gaap-supplement:SouthRegionMember2022-09-300001321741gain:GeographicRegionsConcentrationRiskMemberus-gaap-supplement:SouthRegionMembergain:InvestmentOwnedAtFairValueMember2022-04-012022-09-300001321741us-gaap-supplement:SouthRegionMember2022-03-310001321741gain:GeographicRegionsConcentrationRiskMemberus-gaap-supplement:SouthRegionMembergain:InvestmentOwnedAtFairValueMember2021-04-012022-03-310001321741us-gaap-supplement:MidwestRegionMember2022-09-300001321741us-gaap-supplement:MidwestRegionMembergain:GeographicRegionsConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2022-04-012022-09-300001321741us-gaap-supplement:MidwestRegionMember2022-03-310001321741us-gaap-supplement:MidwestRegionMembergain:GeographicRegionsConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2021-04-012022-03-310001321741gain:GeographicRegionsConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2022-04-012022-09-300001321741gain:GeographicRegionsConcentrationRiskMembergain:InvestmentOwnedAtFairValueMember2021-04-012022-03-310001321741srt:ChiefExecutiveOfficerMembergain:TheAdviserMembergain:DavidGladstoneMember2022-09-300001321741srt:MinimumMember2022-04-012022-09-3000013217412021-04-012022-03-310001321741srt:ChiefExecutiveOfficerMembergain:TheAdministratorMembergain:DavidGladstoneMember2022-09-300001321741srt:ChiefExecutiveOfficerMembergain:GladstoneSecuritiesLLCMembergain:DavidGladstoneMember2022-09-300001321741srt:AffiliatedEntityMember2022-07-012022-09-300001321741srt:AffiliatedEntityMember2022-04-012022-09-300001321741srt:AffiliatedEntityMember2021-07-012021-09-300001321741srt:AffiliatedEntityMember2021-04-012021-09-300001321741gain:TheAdviserMember2022-09-300001321741gain:TheAdviserMember2022-03-310001321741gain:TheAdministratorMember2022-09-300001321741gain:TheAdministratorMember2022-03-310001321741us-gaap:RevolvingCreditFacilityMember2021-03-082021-03-080001321741us-gaap:RevolvingCreditFacilityMember2022-04-012022-09-300001321741gain:RevolvingLineOfCreditMemberus-gaap:LineOfCreditMemberus-gaap:RevolvingCreditFacilityMemberus-gaap:LondonInterbankOfferedRateLIBORMember2020-08-102020-08-100001321741gain:RevolvingLineOfCreditMemberus-gaap:LineOfCreditMemberus-gaap:RevolvingCreditFacilityMember2020-08-090001321741gain:RevolvingLineOfCreditMemberus-gaap:LineOfCreditMemberus-gaap:RevolvingCreditFacilityMember2020-08-100001321741gain:LondonInterbankOfferedRateLIBORTrancheOneMembergain:RevolvingLineOfCreditMemberus-gaap:LineOfCreditMemberus-gaap:RevolvingCreditFacilityMember2020-08-102020-08-100001321741gain:RevolvingLineOfCreditMembergain:LondonInterbankOfferedRateLIBORTrancheTwoMemberus-gaap:LineOfCreditMemberus-gaap:RevolvingCreditFacilityMember2020-08-102020-08-100001321741gain:LondonInterbankOfferedRateLIBORThereafterMembergain:RevolvingLineOfCreditMemberus-gaap:LineOfCreditMemberus-gaap:RevolvingCreditFacilityMember2020-08-102020-08-100001321741gain:RevolvingLineOfCreditMembergain:LessThanOrEqualTo50OfCommitmentMemberus-gaap:LineOfCreditMemberus-gaap:RevolvingCreditFacilityMember2020-08-102020-08-100001321741gain:RevolvingLineOfCreditMemberus-gaap:LineOfCreditMembergain:GreaterThan50ButLessThanOrEqualTo65OfCommitmentMemberus-gaap:RevolvingCreditFacilityMember2020-08-102020-08-100001321741gain:RevolvingLineOfCreditMemberus-gaap:LineOfCreditMemberus-gaap:RevolvingCreditFacilityMembergain:GreaterThan65OfCommitmentMember2020-08-102020-08-100001321741gain:RevolvingLineOfCreditMemberus-gaap:LineOfCreditMemberus-gaap:RevolvingCreditFacilityMember2022-09-300001321741gain:RevolvingLineOfCreditMemberus-gaap:LineOfCreditMemberus-gaap:RevolvingCreditFacilityMember2022-03-310001321741gain:RevolvingLineOfCreditMemberus-gaap:LineOfCreditMemberus-gaap:RevolvingCreditFacilityMember2022-07-012022-09-300001321741gain:RevolvingLineOfCreditMemberus-gaap:LineOfCreditMemberus-gaap:RevolvingCreditFacilityMember2021-07-012021-09-300001321741gain:RevolvingLineOfCreditMemberus-gaap:LineOfCreditMemberus-gaap:RevolvingCreditFacilityMember2022-04-012022-09-300001321741gain:RevolvingLineOfCreditMemberus-gaap:LineOfCreditMemberus-gaap:RevolvingCreditFacilityMember2021-04-012021-09-300001321741gain:RevolvingLineOfCreditMemberus-gaap:LineOfCreditMemberus-gaap:RevolvingCreditFacilityMembersrt:MinimumMember2022-09-300001321741gain:RevolvingLineOfCreditMemberus-gaap:LineOfCreditMemberus-gaap:RevolvingCreditFacilityMemberus-gaap:LondonInterbankOfferedRateLIBORMember2022-04-012022-09-300001321741gain:RevolvingLineOfCreditMemberus-gaap:LineOfCreditMemberus-gaap:RevolvingCreditFacilityMemberus-gaap:LondonInterbankOfferedRateLIBORMember2021-04-012022-03-310001321741us-gaap:LineOfCreditMemberus-gaap:RevolvingCreditFacilityMember2022-04-012022-09-300001321741us-gaap:LineOfCreditMemberus-gaap:RevolvingCreditFacilityMember2021-04-012022-03-310001321741us-gaap:LongTermDebtMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Member2022-06-300001321741us-gaap:LongTermDebtMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Member2022-07-012022-09-300001321741us-gaap:LongTermDebtMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Member2022-09-300001321741us-gaap:LongTermDebtMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Member2022-03-310001321741us-gaap:LongTermDebtMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Member2022-04-012022-09-300001321741us-gaap:LongTermDebtMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Member2021-06-300001321741us-gaap:LongTermDebtMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Member2021-07-012021-09-300001321741us-gaap:LongTermDebtMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Member2021-09-300001321741us-gaap:LongTermDebtMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Member2021-03-310001321741us-gaap:LongTermDebtMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Member2021-04-012021-09-300001321741us-gaap:NotesPayableOtherPayablesMembergain:A500NotesDue2026Member2021-03-310001321741us-gaap:NotesPayableOtherPayablesMembergain:A500NotesDue2026Member2021-03-012021-03-310001321741us-gaap:NotesPayableOtherPayablesMembergain:A4875NotesDue2028Member2021-08-310001321741us-gaap:NotesPayableOtherPayablesMembergain:A4875NotesDue2028Member2021-08-012021-08-310001321741us-gaap:NotesPayableOtherPayablesMembergain:A4875NotesDue2028Member2022-08-310001321741us-gaap:NotesPayableOtherPayablesMembergain:A500NotesDue2026Member2022-09-300001321741us-gaap:NotesPayableOtherPayablesMembergain:A4875NotesDue2028Member2022-09-300001321741us-gaap:NotesPayableOtherPayablesMember2022-09-300001321741us-gaap:NotesPayableOtherPayablesMembergain:A500NotesDue2026Member2022-03-310001321741us-gaap:NotesPayableOtherPayablesMembergain:A4875NotesDue2028Member2022-03-310001321741us-gaap:NotesPayableOtherPayablesMember2022-03-310001321741Ginsey Home Solutions, Inc.2012-08-310001321741Ginsey Home Solutions, Inc.gain:DebtSecuritiesSecuredSecondLienDebtMember2014-05-012014-05-310001321741gain:SeriesETermPreferredStockMember2021-08-012021-08-310001321741gain:SeriesETermPreferredStockMember2021-08-3100013217412021-08-012021-08-310001321741gain:SeriesETermPreferredStockMember2021-04-302021-04-300001321741gain:SeriesETermPreferredStockMember2021-05-282021-05-280001321741gain:SeriesETermPreferredStockMember2021-06-302021-06-300001321741gain:SeriesETermPreferredStockMember2021-07-302021-07-300001321741gain:SeriesETermPreferredStockMember2021-08-312021-08-310001321741gain:SeriesETermPreferredStockMember2021-04-012021-09-3000013217412021-12-3100013217412021-09-030001321741gain:CommonStockATMProgramMember2022-08-310001321741gain:CommonStockATMProgramMember2022-09-300001321741gain:CommonStockATMProgramMember2022-04-012022-09-300001321741gain:CommonStockATMProgramMember2022-07-012022-09-300001321741gain:CommonStockATMProgramMember2021-07-012021-09-300001321741gain:CommonStockATMProgramMember2021-04-012021-09-3000013217412022-04-292022-04-2900013217412022-05-312022-05-3100013217412022-06-152022-06-1500013217412022-06-302022-06-3000013217412022-07-292022-07-2900013217412022-08-312022-08-3100013217412022-09-302022-09-3000013217412021-04-302021-04-3000013217412021-05-282021-05-2800013217412021-06-172021-06-1700013217412021-06-302021-06-3000013217412021-07-302021-07-3000013217412021-08-312021-08-3100013217412021-09-152021-09-1500013217412021-09-302021-09-300001321741Country Club Enterprises, LLC – Guarantyus-gaap:GuaranteesMember2022-04-012022-09-300001321741us-gaap:UnusedLinesOfCreditMember2022-04-012022-09-300001321741us-gaap:UnusedLinesOfCreditMember2020-04-012021-03-310001321741us-gaap:GuaranteesMember2022-04-012022-09-300001321741us-gaap:GuaranteesMember2020-04-012021-03-3100013217412020-04-012021-03-310001321741gain:DebtSecuritiesSecuredFirstLienDebtMemberNocturne Villa Rentals, Inc.us-gaap:SubsequentEventMember2022-10-012022-10-310001321741us-gaap:SubsequentEventMember2022-10-312022-10-310001321741us-gaap:SubsequentEventMembersrt:ScenarioForecastMember2022-11-302022-11-300001321741us-gaap:SubsequentEventMembersrt:ScenarioForecastMember2022-12-152022-12-150001321741us-gaap:SubsequentEventMembersrt:ScenarioForecastMember2022-12-302022-12-300001321741us-gaap:SubsequentEventMembersrt:ScenarioForecastMember2022-10-012022-12-310001321741gain:Notes2026FivePointZeroMember2022-04-012022-09-300001321741gain:Notes2028FourPointEightSevenFiveMember2022-04-012022-09-30