Like bank deposits, money market instruments function in important ways as money. Yet our financial regulatory regime does not take this proposition seriously. The (non-government) issuers of money market instruments-almost all of which are financial firms, not commercial or industrial ones-perform an invaluable economic function. Like depository banks, they channel economic agents\u27 transaction reserves into the capital markets. These firms thereby reduce borrowing costs and expand credit availability. However, this activity- maturity transformation -presents a problem. When these issuers default on their money market obligations, they generate adverse monetary consequences. This circumstance amounts to a market failure, creating a ...