货币市场
A money market fund (also known as money market mutual fund) is an open-ended mutual fund that invests in short-term debt securities such as US Treasury bills and commercial paper. Money market funds are widely (though not necessarily accurately) regarded as being as safe as bank deposits yet providing a higher yield. Regulated in the US under the Investment Company Act of 1940, money market funds are important providers of liquidity to financial intermediaries. Stable value funds have outperformed money market funds in every 12-month period since 1985 with similar volatility and risk and slightly less liquidity.