U.S. stocks added to gains on Tuesday, with the Dow industrials <.DJI> briefly turning positive for the year, after data showed existing home sales rose more than expected in April.

The Dow Jones industrial average <.DJI> gained 47.45 points, or 0.54 percent, to 8,768.89. The Standard & Poor's 500 Index <.SPX> rose 5.12 points, or 0.54 percent, to 947.99. The Nasdaq Composite Index <.IXIC> added 17.41 points, or 0.95 percent, to 1,846.09.