Nov 5 (Reuters) - Wall Street jumped at the open on Thursday as investors bet on a Republican held Senate that would block any moves by a Joe Biden administration to tighten regulation and raise taxes on corporate America, even as the presidential election remained too close to call. The Dow Jones Industrial Average rose 235.71 points, or 0.85%, at the open to 28,083.37. The S&P 500 opened higher by 42.30 points, or 1.23%, at 3,485.74, while the Nasdaq Composite gained 225.55 points, or 1.95%, to 11,816.33 at the opening bell. (Reporting by Shreyashi Sanyal in Bengaluru; Editing by Sriraj Kalluvila)