The Sensex opened with a negative gap of 84 points at 10,836. The index soon tumbled to a low of 10,732. The index is now down 108 points at 10,812.ICICI Bank has dropped 3.7% to Rs 489. HDFC, Grasim, TCS, Reliance Communications, HDFC Bank, Dr.Reddy's, Hindalco, Bajaj Auto and Maruti are down over 1% each.ONGC and ACC are the sole gainers among the Sensex stocks.