The Sensex has tumbled to the day's low of 10,299 - down 253 points from the day's high of 10,552. The index is now down 132 points at 10,319.Satyam has tumbled 5.3% to Rs 633. ACC has slumped 4.6% to Rs 750.Hindalco has dropped 3.7% to Rs 173. Grasim is down 3.3% at Rs 1,742. HDFC Bank has declined 2.7% to Rs 744.Bharti Airtel, ITC and SBI are down 2% each at Rs 359, Rs 161 and Rs 822, respectively.The market breadth is extremely negative - out of 2,393 stocks traded so far, 1,558 have declined, 791 have advanced and the rest are unchanged.