Portman Ridge Finance Corporation is a business development company that invests in various sectors such as healthcare, logistics & distribution, real estate, and insurance. They primarily invest in companies with EBITDA between $5 million to $25 million, providing senior secured loans, second lien term loans, mezzanine loans, and equity investments of up to $20 million. They also make acquisitions in businesses complementary to their own, and invest alongside private equity sponsors in minority or majority equity positions.