The Exchange Stabilization Fund (ESF) is an emergency reserve fund of the United States Treasury Department, normally used for foreign exchange intervention. This arrangement (as opposed to having the central bank intervene directly) allows the US government to influence currency exchange rates without directly affecting domestic money supply.
As of October 2009, the fund held assets worth $105 billion, including $58.1 billion in special drawing rights (SDR) from the International Monetary Fund.
