An acronym for money market fund; a category of money market vehicles (MMV) that represents a type of mutual fund or similar structure investing in the money market, i.e., in high-quality, short-term debt securities and cash equivalents. Money market funds are investments in short-term fixed-income securities or cash-like securities.

These funds are designed to provide high liquidity combined with lower risk (credit risk) as compared to other cash products. This entails stability of capital (invested amount) and typically better yields.

Money market funds differ from money market accounts (MMAs) in the sense that money market funds (also known as money market mutual funds) are investments, not deposit accounts. At the backend, investments are run through a fund structure, and do not entitle share owners access to their funds through cards or checking facility.