The Indian stock markets recorded huge slump in today's session with both benchmark indices ending in negative. The Sensex at the Bombay stock exchange tumbled over 491 points to close at 15405. All the sectoral indices on the BSE were lower with the realty index down over 9 per cent. The metal index fell by 6 per cent while oil and gas plunged over 4 per cent. The Nifty at the National Stock Exchange also saw a sharp sell-off today and slipped towards the 4500 level. It fell for the sixth consecutive day on huge volumes and closed below the 4,600 mark for the first time since September 3, 2009. It closed at 4564 plunging by 148 points.