A money market fund is a type of mutual fund that invests in short-term, low-risk securities such as Treasury bills, commercial paper, and certificates of deposit. These funds are designed to provide investors with a safe and liquid place to park their cash while earning a modest return. Money market funds are known for their stability and typically aim to maintain a stable net asset value (NAV) of $1 per share. They are often used by individuals and institutions as an alternative to traditional savings accounts or as a temporary investment option for funds that may be needed in the near future.