Gladstone Investment Corp operates as an externally managed, closed-end, non-diversified management investment company. Its objective is to invest in debt and equity securities of established private businesses operating in the U.S. and to achieve and grow current income by investing in debt securities of established businesses; provide the stockholders with long-term capital appreciation in the value of its assets by investing in equity securities of established businesses. It focuses on investing in lower-middle-market private businesses.