FXstreet.com (San Francisco) - U.S. stocks recorded sharp gains on Friday, as investors turn optimistic that the U.S. central bank will step in with more tools to stimulate the economy, as well as fresh stimulus from the European Central Bank. The Dow Jones Industrial Average rallied 100.51 points, or 0.8% to 13,157.97 to record a 0.7% loss on the week, its first weekly loss since early July. The S&P 50 index added 9.05 points, or 0.7% to 1,411.13 to record a 0.5% loss on the week. The Nasdaq Composite jumped 16.39 points, or 0.5%, to 3,069.79.