U.S. stocks ended higher in a volatile session Thursday. The Dow Jones industrial average rose 193.24, or 0.6 percent, to 31,774.52. The broader Standard & Poor's 500 index rose 26.31, or 0.7 percent, to 4,006.18. The technology-heavy Nasdaq composite index rose 70.23, or 0.6 percent, to 11,862.13. Oil rose. West Texas Intermediate (WTI) crude futures climbed $1.42, or 1.7 percent, to $83.30 a barrel, after dropping to $81.20, their lowest since early January.
