June 24 (Reuters) - The S&P 500 and the Nasdaq opened at all-time highs on Thursday, boosted by shares of Tesla and other top-shelf technology firms as data showing fewer weekly jobless claims pointed to a steady recovery in the labor market. The S&P 500 opened higher by 15.13 points, or 0.36%, at 4,256.97, while the Nasdaq Composite rose 85.5 points, or 0.60%, to 14357.265 at the opening bell. The Dow Jones Industrial Average rose 59.67 points, or 0.18%, at the open to 33,933.91. (Reporting by Medha Singh in Bengaluru; Editing by Maju Samuel) Our Standards: The Thomson Reuters Trust Principles.