Feb 10 (Reuters) - Wall Street’s main indexes opened at record highs on Wednesday, supported by positive earnings updates, while investors looked to a speech by Federal Reserve Chair Jerome Powell for clues on the pace of an economic rebound. The Dow Jones Industrial Average rose 52.2 points, or 0.17%, at the open to 31428.02. The S&P 500 rose 9.6 points, or 0.24%, at the open to 3920.78, while the Nasdaq Composite rose 85.6 points, or 0.61%, to 14093.347 at the opening bell. (Reporting by Devik Jain in Bengaluru; Editing by Maju Samuel)