The Sensex at the Bombay Stock Exchange plunged 387 points, its biggest single day loss in over two months, at 16,353, today, after the Reserve Bank, in its quarterly credit policy review, asked banks topark more money in government securities and raised its inflation forecast. This was the sixth straight day of losses for the Sensex. The Nifty at the National Stock Exchange slid 124 points, or 2.5 percent, to 4,847.Markets in Japan, China, Hong Kong, Singapore and South Korea slipped between 0.5 percent and 3 percent, today. Wall Street had lost 1 percent, overnight.