U.S. stocks closed lower on Thursday, with the S&P 500 on track for one of its worst weeks of the year, as a string of cautionary comments on inflation from Federal Reserve officials raised concerns about further interest-rate hikes. The Dow Jones industrial average fell 30.26 points, or 0.29 percent, to end unofficially at 10,287.10. The Standard & Poor's 500 Index slipped 4.90 points, or 0.41 percent, to finish at 1,191.49. The technology-laced Nasdaq Composite Index dropped 18.94 points, or 0.90 percent, to close at 2,084.08.
