â¿¿Oct. 15, 2010: Bernanke signals the Fed will buy more government bonds to boost the economy, drive down unemployment and protect against deflation.â¿¿ Nov. 3, 2010: The Fed announces it will buy $600 billion more in Treasury bonds to try to hold down longer-term rates. â¿¿ June 22, 2011: The Fed confirms it will complete its purchases of $600 billion in Treasury bonds by the end of the month. The purchases were intended to drive down rates on mortgages and other debt. â¿¿ Aug. 9, 2011: It says it plans to keep its benchmark short-term rate at nearly zero until mid-2013. It's the first time the Fed has set a target for keeping the rate at that level for a specific period. The date reflects its assessment that the economy will remain weak. â¿¿ Sept. 21, 2011: Through a program called Operation Twist, the Fed says it will sell $400 billion of its shorter-term securities to buy longer-term holdings to try to lower Treasury yields further. The Fed also says it will reinvest its holdings of mortgage-backed securities, which could help keep mortgage rates at super-low levels. â¿¿ Jan. 25, 2012: The Fed says it's unlikely to raise interest rates until late 2014 at the earliest, extending a period of record-low rates by at least a year and a half. â¿¿ June 20, 2012: The central bank says it's extending Operation Twist through the end of 2012. And it says it's prepared to act further if the economy deteriorates. â¿¿ Sept. 13, 2012: The Fed says it will spend $40 billion a month to buy mortgage bonds for as long as it deems necessary to make home buying more affordable. It plans to keep short-term interest rates at record lows through mid-2015. And it's ready to try other stimulative measures if hiring doesn't pick up.