Wall Street opens slightly lower after Yellen comments

US stocks opened marginally lower on Wednesday as Federal Reserve Chair Janet Yellen said the US central bank remained on track to raise interest rates this year.

The Dow Jones industrial average fell 12.3 points, or 0.07 percent, to 18,041.28. The S&P 500 lost 0.76 points, or 0.04 percent, to 2,108.19 and the Nasdaq Composite gained 4.35 points, or 0.09 percent, to 5,109.24.