Lifted by rising global markets, the Sensex at the Bombay Stock Exchange surged 337 points—its biggest single day gain in two months–to close at a two-week high of 17,684, on all-round buying by funds, today. The Nifty at the National Stock Exchange spurted 104 points, or 2 percent, to 5,342.Markets rallied across the globe, after the European Central Bank announced an unlimited bond-buying program to reduce borrowing costs for the region's most indebted nations. So key stock indices in Japan, China, Hong Kong, South Korea and Singapore posted strong gains of between 0.8 percent and 3.7 percent.