U.S. stocks rose Wednesday in another volatile session. The Dow Jones industrial average rose 91.67, or 0.4 percent, to 23,879. The broader Standard & Poor's 500 index rose 10.55, or 0.4 percent, to 2,584.96. The technology-heavy Nasdaq composite index rose 60.08, or 0.9 percent, to 6,957.08.