Just one week after surging to their best weekly gain in years, U.S. stocks gave almost all of it back last week, suffering their worst loss since March. It was a curious week to say the least. After receiving some reassuringly dovish commentary from the Fed the week before, stocks were poised to rally further on word from Buenos Aires of a cease fire on the trade front with China. And it came. But the rally faded quickly, lasting only through Monday, after which stocks turned sharply lower. The S&P 500 lost 4.6 percent on the week, leaving it lower on the year by 1.5 percent and back in correction territory from its high on September 20.