Investors were encouraged by two U.S. economic reports early Thursday, a slight decrease in applications for unemployment benefits and a narrower trade deficit.
The Dow Jones industrial average was up 36 points at 12,968 shortly after the opening bell.
The Standard & Poor's 500 index was up five at 1,399 and the Nasdaq composite was up 10 points at 2,947.
Monster Beverage fell 8 percent after the drink maker said its revenue growth slowed in the third quarter. The government is investigating reports of five deaths and a non-fatal heart attack in people who consumed the company's highly caffeinated Monster Energy Drink.
Dean Foods rose 6 percent after reporting higher earnings.
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