NEW YORK (Reuters) - U.S. stocks opened higher on Tuesday, lifted by a round of positive earnings reports, including from Dow component Merck & Co .
Shares of Merck rose 2.1 percent to $57.82.
The Dow Jones industrial average <.DJI> was up 31.59 points, or 0.19 percent, at 16,480.33. The Standard & Poor's 500 Index <.SPX> was up 4.25 points, or 0.23 percent, at 1,873.68. The Nasdaq Composite Index <.IXIC> was up 12.72 points, or 0.31 percent, at 4,087.12.
(Reporting by Ryan Vlastelica; Editing by Bernadette Baum)