Source: Board of Governors of the Federal Reserve System (US)  

Release: H.4.1 Factors Affecting Reserve Balances  

Units:  Billions of U.S. Dollars, Not Seasonally Adjusted

Frequency:  Weekly, Ending Wednesday

The face value of U.S. Treasury securities and federal agency debt securities lent overnight through the Federal Reserve Bank of New York's securities lending program. This program provides a temporary source of U.S. Treasury securities and federal agency debt securities to foster efficient and liquid trading in the market for these securities. More information can be found at http://www.federalreserve.gov/monetarypolicy/bst_fedsbalancesheet.htm.