NEW YORK, New York - U.S. stocks closed sharply higher on Wednesday adding to the volatility this week which has seen extremes in both directions and intra-day U-turns.

"You have the normal concern ... investors who want to protect profits on some of these (growth) stocks, and the investors who were looking for a pullback to re-enter," Rick Meckler, partner at Cherry Lane Investments in New Vernon, New Jersey told Reuters Thomson Wednesday.

"As these two sides participate in the market, you're getting these big swings back and forth, buyers on the dip and sellers when it gets back to higher levels."

The biggest winner of the day was the Dow Jones which added 424.51 points or 1.35 percent to 31,961.86.

The Standard and Poor's 500 climbed 44.06 points or 1.14 percent to 3,925.43.

The Nasdaq Composite advanced 132.77 points or 0.99 percent to 13,597.97.

The U.S. dollar was sold off sharply against the commodity currencies. The euro was robust too, rising to 1.2163. The British pound was solid at 1.4135. The Japanese yen slipped to 105.88. The Swiss franc was also unwanted, but steady at 0.9071.

The Canadian dollar firmed to 1.2511. The Australian dollar shot up to 0.7963, while the star performer of the day Thursday was the New Zealand dollar which soared to 0.7444.

On Asian markets, the biggest mover was the Hang Seng in Hong Kong which at one stage was down well over 1,000 points. It recovered slightly to close down 914.40 points or 2.99 percent at 29,708.24.

In Tokyo, the Nikkei 225 shed 484.33 points or 1.61 percent to close at 29,671.70.

The Australian All Ordinaries declined 61.40 points or 0.86 percent to 7,049.40.

China's Shanghai Composite finished down 72.28 points points or 1.99 percent at 3,564.04.