After a rocky start to the week, U.S. stocks roared back on Thursday, giving major stock indexes their biggest gain of the year. The Dow Jones industrial average and the S&P 500 index each closed up 1.2 percent, their largest single-day increase since Dec. 18. The rally helped the market rebound a day after a modest loss and continued a gradual comeback since a plunge of more than 2 percent on Monday.
Thursday’s gains were broad. All 10 of the S&P 500’s sectors rose. Three stocks rose for every one that fell.