Investopedia explains: Learn about institutional investing and some of the major players in this field. : Institutional investors are organizations that pool together funds on behalf of others and invest those funds in a variety of different financial instruments and asset classes. They include investment funds, insurance funds and pension funds. Institutional investors control a significant amount of all financial assets in the United States and exert considerable influence in all markets. This influence has grown over time and can be confirmed by examining the concentration of ownership by institutional investors in the equity of publicly traded corporations.