Mutual funds are professionally managed pools of money. The term is commonly applied to regulated open-end funds sold to the general public. In the United States, mutual funds are regulated by the Investment Company Act of 1940. Mutual funds may be open-end funds, closed-end funds or unit investment trusts. The price of a mutual fund is set at the end of each trading day, based on the underlying securities of the fund (as opposed to ETFs, which trade throughout the day). Mutual fund expenses include commissions, redemption fees and operational fees.