The Dow Jones industrial average rose to the tenth biggest point gain in its history, and its best since March 2009. The Federal Reserve pledged to keep its key interest rate at its record low of nearly zero through the middle of 2013. The central bank also said that it has discussed "the range of policy tools" it can use to spur the economy.
The Dow Jones industrial average rose 429.92 points, or 4 percent, to 11,239.77.
The Standard & Poor's 500 index rose 53.07, or 4.7 percent, to 1,172.53.
The Nasdaq composite rose 124.83, or 5.3 percent, to 2,482.52.
For the week to date:
The Dow is down 204.84, or 1.8 percent.
The S&P is down 26.85, or 2.2 percent.
The Nasdaq is down 26.04, or 1.1percent.
For the year to date:
The Dow is down 333.74, or 2.9 percent.
The S&P is down 85.11, or 6.8 percent.
The Nasdaq is down 170.35, or 6.4 percent.