The Sensex at the Bombay Stock Exchange surged 422 points, or 2.6 percent, to a one-month high of 16,958, on encouraging quarterly results by IT major, Infosys, and rising Asian and European markets, today. The Nifty at the National Stock Exchange climbed 125 points, or 2.5 percent, to 5,099.Stock markets in China, Hong Kong, Singapore and South Korea gained between 0.8 percent and 3 percent.