The Sensex opened with a positive gap of 133 points at 11,072. The index touched a high of 11,143, but soon slipped into the negative zone.Unabated selling pressure has dragged the index to the day's low of 10,508 - down 431 points from its previous close.There is not a single gainer among the Sensex stocks.Tata Motors has plunged almost 10% to Rs 767. Maruti and Bajaj Auto have tumbled nearly 5% each to Rs 749 and Rs 2,808, respectively.Dr.Reddy's and Cipla have slumped nearly 6% each to Rs 1,427 and Rs 208, respectively.Hindalco has dropped 6.5% to Rs 177. Larsen & Toubro has shed 6% to Rs 2,352.HDFC Bank and NTPC are down over 5% each to Rs 770 and Rs 111, respectively.Out of 2,126 stocks traded so far, 1,902 have declined, 194 have advanced and 30 are unchanged.