Monetary Aggregate

A grouping of assets sufficiently liquid to be defined as a measure of money.

In the United States, the standardized monetary aggregates and their measured contents are known as:

M1 – Physical cash and coins plus demand deposits, traveler’s checks
M2 – All of M1 plus savings deposits, money market shares
M3 - All of M2 plus larger (greater than $100,000) time deposits and institutional funds.

The Federal Reserve uses monetary aggregates to measure the effects of open-market operations.