Stocks posted their best day in the last nine on Thursday in response to signs of health in the euro-zone debt market and as investors snapped up energy shares crushed in the previous day's sell-off.

* The Dow Jones industrial average <.DJI> gained 273.28 points, or 2.76 percent, to end unofficially at 10,172.53. The Standard & Poor's 500 Index <.SPX> jumped 31.15 points, or 2.95 percent, to finish unofficially at 1,086.84. The Nasdaq Composite Index <.IXIC> climbed 59.86 points, or 2.77 percent, to close unofficially at 2,218.71.

(Reporting by Leah Schnurr; Editing by Jan Paschal)