Money Supply The entire quantity of bills, coins, loans, credit and other liquid instruments in a country's economy. Investopedia Says: Money supply is divided into multiple categories - M0, M1, M2 and M3 - according to the type and size of account in which the instrument is kept. The money supply is important to economists trying to understand how policies will affect interest rates and growth. Related Terms: Equation Of Exchange Liquidity Squeeze M0 M1 M2 M3 Monetary Base Monetary Policy Narrow Money Velocity (of Money) |