A money market mutual fund like the Vanguard Prime Money Market fund works like any other mutual fund. Money market funds are relatively low-risk investments. Retail money market funds are defined as money market funds that are generally limited to natural persons. Money market funds will invest in things like T-bills, commercial paper, and other very low risk types of investments. This article discusses the top 40 low cost best money market mutual funds for your savings investments — either directly with the mutual fund company or through retirement investment programs that include this money market savings fund as an option. Types of money market funds.  You could lose money by investing in a money market fund. They are considered one of the safest investments you can make. Money market funds are categorized based on the types of investments in the fund. Money market funds are a type of mutual fund that invests in cash and cash-equivalent securities. If you’re looking for a money market fund provider that offers flexible options and online evaluation tools, you may want to consider using Fidelity.The investment company offers government, prime and municipal money market fund options that you can invest in. The 7 best money market fund brokers of 2020 Fidelity – Best for online tools. A money market fund is one of the most common places to park money between larger investments. A money market fund will bring you a small and steady rate of return. In contrast, a money market mutual fund — or money market fund — isn’t FDIC-insured. Money market mutual funds, also known as money market funds, are fixed-income mutual funds that invest in high-quality, short-term debt. Money market funds are considered “safe” investments because these loans come due within a very short period of time—usually 90 days or less. Money Market Funds. 1 These conservative funds invest in short-term debt instruments like … Fidelity offers government, prime, and municipal (or tax-exempt) money market funds, and is an industry leader, managing over $800 billion in total money market assets. Although the fund seeks to preserve the value of your investment at $1 per share, it cannot guarantee it will do so. The Top 40 Low Cost Best US Money Market Funds You can save by investing in one of the top 40 low cost best money market funds. Money market funds won't make you rich, but they're a good place to put money that you need in the short run. On the risk scale, they’re less risky than investing in stocks but riskier than parking your money in a savings account. A money market fund is an investment product.