In response, on Friday, September 19, 2008, the U.S. Department of the Treasury announced an optional program to "insure the holdings of any publicly offered eligible money market mutual fund—both retail and institutional—that pays a fee to participate in the program". The insurance guaranteed that if a covered fund had broken the buck, it would have been restored to $1 NAV. The program was similar to the FDIC, in that it insured deposit-like holdings and sought to prevent runs on the bank. The guarantee was backed by assets of the Treasury Department's Exchange Stabilization Fund, up to a maximum of $50 billion. This program only covered assets invested in funds before September 19, 2008, and those who sold equities, for example, during the subsequent market crash and parked their assets in money funds, were at risk. The program immediately stabilized the system and stanched the outflows, but drew criticism from banking organizations, including the Independent Community Bankers of America and American Bankers Association, who expected funds to drain out of bank deposits and into newly insured money funds, as these latter would combine higher yields with insurance. The guarantee program ended on September 18, 2009, with no losses and generated $1.2 billion in revenue from the participation fees.
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.