One example might be when you have saved up a down payment for your first home and are simply waiting to find the perfect house. The stock market might be too risky since you want to buy the house soon and market volatility could eat up some of your investment. Yet the balance is large enough that you don’t want to miss out on earning interest by just having it sit in a conventional saving, or worse, checking account.
The Money Market enables the commercial banks to use their excess reserves in profitable investment. The main objective of the commercial banks is to earn income from its reserves as well as maintain liquidity to meet the uncertain cash demand of the depositors. In the money market, the excess reserves of the commercial banks are invested in near-money assets (e.g., short-term bills of exchange), which are easily converted into cash. Thus, commercial banks earn profits without sacrificing liquidity.