Institutional Investor

An institutional investor is an organization, rather than an individual, that pools large amounts of capital to invest: pension funds, mutual funds, hedge funds, insurance companies, and endowments. Institutions account for the large majority of daily US equity trading volume.

Because institutions trade in size, their buying and selling can move prices in ways an individual investor's trade never would, and their required disclosures (like the 13F filing) are one of the few public windows retail investors have into what large, well-resourced investors are actually doing.