The Bombay Stock Exchange benchmark Sensex surged by 300 points in opening trade on Friday on fresh buying by funds and retail investors, bolstered by firming global trends following a higher than expected growth in the US economy.The 30-share BSE barometer rose by 300 points, or 1.87 per cent, to 16,353 points. The wide-based National Stock Exchange index Nifty surged by 101 points, or 2.06 per cent to 4,851 points.