S&P 500, Dow Top Previous Closing Record

U.S. stocks opened slightly higher on Thursday, boosted by better-than-expected earnings results from Wal-Mart Stores Inc. . The S&P 500 and Dow Jones Industrial Average moved above their previous closing record levels, reached on Tuesday. The S&P 500 added 2 points, or 0.1%, to 2,040.85. The Dow Jones Industrial Average rose 32 points, or 0.2% to 17,641.56. The Nasdaq Composite gained 8 points, or 0.2%, to 4,683.