Money market mutual fund

A money market mutual fund is a fund that invests in highly liquid assets such as cash, debt-based securities, and cash-equivalent securities. The goal when investing in a money market mutual fund is often to invest in assets that are highly liquid and have lower levels of overall risk.
Example: US Treasuries are a great example of a type of asset that one might invest in with a money market mutual fund. They’re fixed-rate securities with long terms and low risk.