Lifted by rising global markets, the Sensex at the Bombay Stock Exchange surged a massive 568 points–its biggest single-day gain in nearly six months–to close well above the 16,000 level, at 16,416, on Monday. The Nifty at the National Stock Exchange spurted 172 points, or 3.6 percent, to 4,920.Stock markets in Japan, Hong Kong, South Korea and Singapore gained between 0.6 percent and 2.8 percent, after US central bank chief, Ben Bernanke's speech encouraged investors.