The BSE Sensex which rallied by over 220 points in opening trade today, stood at 188 points in the positive territory at 17,670 when reports last came in.The 30-share index surged on the back of a rise in oil and gas, auto, metal, realty and IT sector stocks.In a similar fashion, the wide-based National Stock Exchange Nifty was trading 53 points in the green at 5,318.