A professionally managed group of investments bought using a pool of money from many investors is called a "mutual fund." In a mutual fund, investors buy shares, and the money from the sale of shares is pooled together to invest in a diversified portfolio of stocks, bonds, or other securities. The mutual fund is managed by a professional investment management team, who make decisions about which securities to buy and sell in order to achieve the fund's investment objectives. The returns on the mutual fund are then distributed to the investors in proportion to their holdings in the fund. Mutual funds are a popular investment option for individuals who want to diversify their portfolios and access professional investment management services.