On Wednesday, March 18, 2009, the FOMC announced the expansion of the Federal
Reserve's program to purchase agency MBS to a total of $1.25 trillion by the end
of the year. This program offsets the several Federal Reserve Special Facilities
established during the financial crisis of late 2008. This transfer of assets
results in quantitative easing which is essentially the process of "printing
money."
The chart shows the reduction of the Federal Reserve's Special Facilities (red
line) and the addition of Mortgage-Backed securities to the Federal Reserves
System Open Market Account (SOMA) (green line).
References:
http://www.newyorkfed.org/markets/mbs_FAQ.HTML
http://en.wikipedia.org/wiki/Quantitative_easing