July 31 (Reuters) - The S&P 500 and the Nasdaq opened at record highs on Thursday, as blockbuster earnings from Meta and Microsoft signaled Big Tech's hefty artificial intelligence bets were paying off.
The Dow Jones Industrial Average .DJI rose 204.5 points, or 0.46%, at the open to 44,665.82. The S&P 500 .SPX rose 64.1 points, or 1.01%, at the open to 6,427.02, while the Nasdaq Composite .IXIC rose 327.8 points, or 1.55%, to 21,457.48 at the opening bell.