Golub Capital BDC, Inc. (GBDC) operates as an externally managed, closed-end investment company, specializing as a business development company (BDC) with a non-diversified portfolio management strategy. The firm provides financing through debt instruments and minority equity stakes to middle-market businesses, predominantly those backed by private equity sponsors. GBDC's investment focus covers a diverse range of sectors, including consumer services, automotive, healthcare technology, insurance, medical equipment and supplies, hospitality, foodservice, healthcare providers, IT services, and specialty retail. Its geographical investment mandate is primarily the United States. The company's comprehensive financing offerings include various forms of senior secured debt like first-lien traditional senior debt, "one-stop" facilities, and unitranche loans, alongside junior debt, second-lien, subordinated, and mezzanine loans, as well as direct equity investments and warrants.