Money market funds come with some privileges that most other mutual funds do not have.

You can write checks from your money market fund without charge. Most funds, however, will require that checks be written for a minimum amount—say, $250 or more.

You can use a money market fund for business purposes. You can deposit checks from customers and pay bills out of your account.

A fund can be used as a temporary place to park money that is awaiting investment in another security. Some investors place large sums into these accounts and then withdraw them gradually for placement into stocks and bonds. Many investors also keep cash in their money market funds for emergency use.

Some funds allow you to withdraw cash from ATMs for a fee.

Once you have established a money market fund, you can invest in other funds within the same family without filling out an application.