Stocks jumped at the open on Wednesday as a coordinated action by major central banks to provide liquidity to the global financial system boosted investors' appetite for risky assets.

The Dow Jones industrial average <.DJI> gained 317.57 points, or 2.75 percent, to 11,873.20. The Standard & Poor's 500 Index <.SPX> gained 32.52 points, or 2.72 percent, to 1,227.71. The Nasdaq Composite Index <.IXIC> gained 70.07 points, or 2.79 percent, to 2,585.58.

(Editing by Jeffrey Benkoe)