Money Market Fund

A mutual fund that seeks to maintain a constant net asset value (NAV) of $1 per share while earning a market interest rate for shareholders. Such funds are regulated by the SEC and are comprised of short-term (typically less than one year) securities representing high-quality, liquid debt and monetary instruments. The term may also be used to refer to a Short-Term Investment Fund (STIF), which is a non-mutual fund form of money market fund.