The Sensex opened with a positive gap of 31 points at 11,620, and went on to touch a high of 11,677. However, the index soon plunged into the negative zone and dropped to a low of 11,535.The index has now moved back into the positive zone and is now up 16 points at 11,605.Gujarat Ambuja and Grasim have rallied nearly 2% each to Rs 110 and Rs 2,240, respectively.HDFC Bank, ACC and Infosys have gained over 1% each.Bharti Tele has dropped nearly 2% to Rs 401. Wipro and Hindalco are down nearly 1% each.