As you are well aware, after having run surpluses for a brief period around the turn of the decade, the federal budget has reverted to deficit. The unified deficit swelled to $ billion in fiscal 2003 and appears to be continuing to widen in the current fiscal year.
This clearly includes central banks, both in their own role as market participants but also as the exchange rate is an important channel of monetary policy transmission. In a globalised world, the foreign exchange market is one of the most vital parts of the financial plumbing.