April 29 (Reuters) - The S&P 500 and the Nasdaq indexes opened at record highs on Thursday, helped by a rally in tech stocks, while investors parsed a barrage of quarterly reports and the latest batch of economic data. The Dow Jones Industrial Average rose 35.3 points, or 0.10%, at the open to 33855.64. The S&P 500 rose 23.0 points, or 0.55%, at the open to 4206.14, while the Nasdaq Composite rose 153.5 points, or 1.09%, to 14204.515 at the opening bell. (Reporting by Shivani Kumaresan in Bengaluru; Editing by Anil D’Silva)