U.S. stocks fell slightly Thursday. The Dow Jones industrial average was virtually unchanged, falling 6.46 to 33,547.37. The broader Standard & Poor's 500 index fell 11.95, or 0.3 percent, to 3,946.84. The technology-heavy Nasdaq composite index fell 38.70, or 0.4 percent, to 11,144.96. Oil fell and West Texas Intermediate (WTI) crude futures dropped $3.95, or 4.6 percent, to $81.64 a barrel.