Stocks Plunge on Europe, S&P 500 Loses Most in 13 Months

May 20 (Bloomberg) -- Bloomberg's Deborah Kostroun reports on the performance of the U.S. equity market today. U.S. stocks plunged, with the Standard & Poors 500 Index losing the most in 13 months, after jobless claims increased and concern grew that Europes debt crisis is spreading. Bloomberg's Pimm Fox also speaks. (Source: Bloomberg)