The money market is a component of the economy that provides short-term funds. The money market deals in short-term loans, generally for a period of a year or less.

As short-term securities became a commodity, the money market became a component of the financial market for assets involved in short-term borrowing, lending, buying and selling with original maturities of one year or less. Trading in money markets is done over the counter and is wholesale.

There are several money market instruments in most Western countries, including treasury bills, commercial paper, banker's acceptances, deposits, certificates of deposit, bills of exchange, repurchase agreements, federal funds, and short-lived mortgage- and asset-backed securities. The instruments bear differing maturities, currencies, credit risks, and structures. A market can be described as a money market if it is composed of highly liquid, short-term assets. Money market funds typically invest in government securities, certificates of deposit, commercial paper of companies, and other highly liquid, low-risk securities. The four most relevant types of money are commodity money, fiat money, fiduciary money (cheques, banknotes), and commercial bank money. Commodity money relies on intrinsically valuable commodities that act as a medium of exchange. Fiat money, on the other hand, gets its value from a government order.

Money markets, which provide liquidity for the global financial system including for capital markets, are part of the broader system of financial markets.