The Dow Jones Industrial Average hit an all-time high shortly after 1500 GMT, reaching 18,934.05, as investors favored healthcare and financial stocks. But major tech players saw their share prices fall.
The Dow Jones Industrial Average finished up 0.1 percent at 18,868.55. But the broader S&P 500 slipped less than 0.1 percent at 2,164.21 and the Nasdaq fell 0.4 percent to 5,218.40.
Large players in the healthcare industry posted strong gains, with UnitedHealth Group rising 4 percent, Anthem Inc moving up 3.6 percent and Cigna Corporation adding 1.4 percent.
Samsung's announcement on Monday that it would purchase the automotive electronics company Harman International saw Harman's share price finish up more than 25 percent at $109.72 but that was shy of Samsung's per-share offer of $112.