The combination of funds from different sources to finance a common objective/ project. For example, a hedge fund usually commingles investor’s money in one or more securities account for the purpose of buying and selling securities.

It could also refer to a group of investors who lobby together to use their mutual influence in an attempt to manipulate prices and/ or volumes of securities. By a pool, it was possible to acquire the funds needed to manipulate a stock with a large market value. Such a practice was popular in the 1920s and early 1930s but at present time, thanks to heavy regulations, it is no more in application.