The Dow Jones industrial average surged 490.05 points, or 4.24 percent, to 12,045.68, once again positive for the year.

　　The Standard & Poor's 500 rallied 51.77 points, or 4.33 percent, to 1,246.96, the biggest percentage gain since Aug. 11.

　　The Nasdaq Composite Index soared 104.83 points, or 4.17 percent, to 2,620.34, almost erased the month's losses.

　　All 10 S&P 500 big-cap sectors finished higher, with financials and materials taking the lead in the market.

　　Both JP Morgan Chase and Caterpillar soared more than 8.2 percent, the best performers in the Dow's 30 components.

　　The CBOE Volatility Index, widely considered the best gauge of fear in the market, tumbled to finish below 28 for the first time since early November.

　　The euphoria came after the world's major central banks, including the ECB, Federal Reserve, Bank of England, and the central banks of Canada, Japan and Switzerland decided to jointly take action to"enhance their capacity to provide liquidity support to the global financial system."

　　EU finance ministers also agreed to ramp up the firepower of their rescue fund but left a number of questions unanswered, including the exact size of the increased fund.

　　Further boosting sentiment, China cut its banks' reserve requirements for the first time in nearly three years to prevent the economy from abrupt slowdown.

　　Wednesday's economic data came in better than expected, also gave the market a strong lift.

　　The ADP National Employment Report showed that U.S. employers added 206,000 jobs in November, much higher than market expectations.

　　Pending home sales, according to figures from the National Association of Realtors, increased 10.4 percent in October, which was the biggest gain since November 2010.

　　Meanwhile, business activity in the Midwest grew faster than estimates in November as orders surged. The Institute for Supply Management-Chicago business barometer rose to 62.6 from 58.4 in October, well above expectations.

　　In other markets, the U.S. dollar fell against major currencies in late New York trading on Wednesday while crude oil prices continued to climb and topped 100 dollars a barrel.