The Bombay Stock Exchange benchmark Sensex on Wednesday gained 166 points in early trade on buying in metal, realty and auto stocks by funds.The sensex was trading at 16324 , up by 160 points when reports last came in. Similarly the wide-based National Stock Exchange index Nifty also moved up by over 50 points to 4,880 points.Brokers said revival of buying by funds on better global trend pushed up the Sensex.