Investors are still worried about Europe's debt problems. European leaders said they made progress at a weekend summit but won't unveil concrete plans for containing the crisis until Wednesday.
Caterpillar Inc. became the latest big U.S. company to report strong earnings growth in the third quarter. Its income jumped 44 percent.
Oracle, Cigna and Mattel announced nearly $6 billion worth of acquisitions Monday.
The Dow Jones industrial average is up 33, or 0.3 percent, to 11,842. The S&P 500 is up 4, or 0.3 percent, to 1,242. The Nasdaq is up 13, or 0.5 percent, to 2,651.