he federal reserve board controls the amount of money available in the economy
Open market operations allow the Federal Reserve to increase or decrease the amount of money in the banking system as necessary to balance the Federal Reserve's dual mandates. Open market operations are done through the sale and purchase of United States Treasury security, sometimes called ``Treasury bills'' or more informally ``T-bills'' or ``Treasuries''. The Federal Reserve buys Treasury bills from its primary dealers. The purchase of these securities affects the federal funds rate, because primary dealers have accounts at depository institutions.
Federal Reserve System