As a result, for the past two years we have been using alternative tools to provide additional monetary accommodation. In particular, over the past two years the Federal Reserve has further eased monetary conditions by purchasing longer-term securities on the open market. From December 2008 through March 2010, we purchased about $ trillion in longer-term Treasury, agency, and agency mortgage-backed securities.
In August 2010, we began reinvesting the proceeds from all securities that matured or were redeemed in longer-term Treasury securities, so as to keep the size of our securities holdings roughly constant. Around the same time, we began to signal to financial markets that we were considering providing additional monetary policy accommodation by conducting further asset purchases.