March 29 (Reuters) - Wall Street’s main indexes opened lower on Monday after a surge in the previous session, as global banks said they faced potential losses from a hedge fund’s default on margin calls. The Dow Jones Industrial Average rose 14.7 points, or 0.04%, at the open to 33,087.55. The S&P 500 fell 5.2 points, or 0.13%, at the open to 3,969.31, while the Nasdaq Composite dropped 34.8 points, or 0.26%, to 13,103.971 at the opening bell. (Reporting by Devik Jain in Bengaluru; Editing by Arun Koyyur)