The Dow Jones Industrial Average surged to a new record high Tuesday morning, while the Nasdaq Composite lost ground as tech stocks tumbled. The Dow, which closed at its first record high in two months on Monday, was up 1.3%, a more than 500-point gain, in recent trading. The S&P 500, which is just shy of a record of its own, was up 0.3%, while the Nasdaq Composite was off 0.2%. The Dow's upswing was being led by UnitedHealth (UNH), which was up more than 5% after the insurer reported better-than-expected ...