Mumbai – The Sensex at the Bombay Stock Exchange was up 89.49 points at 31,185.19 and NSE Nifty surged by 24.90 points to 9,641.30. Sun Pharma was the biggest gainer in Sensex.ICICI Bank, HDFC, Maruti Suzuki, Lupin, L&T and HUL were also the gainers in the 30-share BSE Sense. On monday sensex drops 166 points to close at 31,096, amid weakness in the global markets.