The State Street Target Retirement 2020 Fund Class K (ticker: SSBOX) is a mutual fund that is designed to help investors reach their retirement goals by the year 2020. This fund is managed by State Street Global Advisors and is classified as a Class K fund, which typically has lower fees and minimum investment requirements. The fund invests in a mix of stocks, bonds, and other assets to provide a balanced and diversified portfolio for investors approaching retirement.