The Dow Jones industrial average was up 23 points, or 0.1 percent, to 15,544 shortly before noon Eastern Daylight Time Tuesday.
The Standard & Poor's 500 was up four points, or 0.2 percent, to 1,689. Seven of the index's 10 industry sectors rose, led by technology stocks.
The technology-heavy Nasdaq composite rose 28 points, or 0.8 percent, to 3,627. Apple, the biggest component of the index, rose 2 percent to $456.
Investors were keeping a close eye on the Federal Reserve. The central bank began a two-day policy meeting Tuesday.
Goodyear Tire & Rubber jumped 10 percent to $18.74 after its earnings more than doubled. Sales in Latin America rose sharply.