Trading was quiet ahead of the July 4th holiday. Traders weighed a number of positive reports, including Ford's best June auto sales since 2006. Home prices climbed to a seven-year high and factory orders rose.
The Standard & Poor's 500 index was up seven points, or 0.4 per cent, to 1,622 shortly before noon Tuesday.
The Dow Jones industrial average rose 58 points, or 0.4 per cent, to 15,003. The Nasdaq composite was up 14 points, or 0.4 per cent, at 3,449.
U.S. markets will be closed Thursday for Independence Day.
Zynga jumped 9 per cent to $3.34 after the troubled online game maker replaced its CEO.