A benchmark index for Indian equities markets slumped 274 points on Monday following heavy selling in metal, realty and banking stocks as wary investors played safe ahead of assembly election results on Tuesday. The 30-scrip sensitive index (Sensex) of the Bombay Stock Exchange (BSE), which opened in the red at 17,598.42 points, ended the day at 17,362.87 points, down 1.55 per cent or 274.12 points from its previous close at 17,636.99 points. The 50-scrip S&P CNX Nifty of the National Stock Exchange closed 1.47 per cent down at 5,280.35 points. There was heavy selling pressure on metal, realty and banking stocks.