Stocks initially jumped after the Fed announced a half-point cut, but gains proved short-lived. The Dow Jones Industrial Average DJIA, -2.94%  fell nearly 1,000 points at its session low and ended the day down 785.91 points, or 2.9%, at 25,917.41, while the S&P 500 SPX, -2.81%  dropped 2.8% and the Nasdaq Composite COMP, -2.99% lost 3%.