U.S. stocks open lower ahead of Fed Chair speech

U.S. stocks opened lower Tuesday, as investors awaited remarks from U.S. Federal Reserve Chair Janet Yellen for clues on when the central bank may raise interest rates.

Yellen is due to speak on the economic outlook and monetary policy at the Economic Club of New York later Tuesday. Traders will scrutinize her speech for indications on how many rate hikes the Fed is looking at and when.

"For one thing, we hope for a little more coherence than in her post-FOMC press conference, where she was knocked off equilibrium by Steve Liesman's opening question about credibility. The Fed takes its credibility very seriously," said Chris Low, chief economist at FTN Financial.

Meanwhile, a decline in oil prices weighed on the stock markets, as U.S. crude oil futures fell almost 3 percent to nearly 38.28 U.S. dollars a barrel in early Tuesday trading.

Shortly after the opening bell, the Dow Jones Industrial Average lost 59.65 points, or 0.34 percent, to 17,475.74. The S&P 500 shed 5.55 points, or 0.27 percent, to 2,031.50. The Nasdaq Composite Index was down 11.85 points, or 0.25 percent, to 4,754.93.

U.S. stocks closed mixed Monday after wavering between small gains and losses, as investors digested a batch of economic reports. Endi