A quartet of key stocks led by UnitedHealth Group dragged on the Dow to start the holiday-shortened week.
The Dow was down 65 points, or 0.2%, shortly after the market opened on Tuesday. The S&P 500 and Nasdaq Composite were both up 0.1%.
UnitedHealth shaved off 71 points from the Dow due to its stock price north of $500. Unlike the S&P, the Dow is a stock-price weighted index, so firms with large share prices have more pull than firms with large market caps but small share prices.
