Golub Capital BDC, Inc. is an externally managed, non-diversified closed-end management investment company. The Company's investment objective is to generate current income and capital appreciation by investing primarily in one stop and other senior secured loans of United States middle-market companies. It also selectively invests in second lien and subordinated (a loan that ranks senior only to a borrower’s equity securities and ranks junior to all of such borrower’s other indebtedness in priority of payment) loans of, and warrants and minority equity securities in, United States middle-market companies. It also invests in various sectors, which include software, healthcare providers and services, specialty retail, automobiles, diversified consumer services, insurance, healthcare technology, information technology (IT) services, commercial services and supplies, and others. The Company’s investment activities are managed by its investment adviser, GC Advisors LLC.