SAN FRANCISCO (MarketWatch) — U.S. stocks closed lower Thursday, finishing out a strong October, as investors digested the possibility the Federal Reserve may taper asset purchases earlier than expected. The Dow Jones Industrial Average (DJI JIA) fell 73.01 points, or 0.5%, to close at 15,545.75, for an October gain of 2.8%. The S&P 500 Index (SNC:SPX) declined 6.76 points, or 0.4%, to finish at 1,756.55, for a gain of 4.5% for the month. The Nasdaq Composite Index (NASDAQ:COMP) slipped 10.91 points, or 0.3%, to end at 3,919.71, for a 3.9% October gain.