The Sensex is now down 593 points at 15,778.The NSE Nifty is down 166 points at 4,776.Infosys has slumped 7.7% to Rs 1,410. HDFC Bank has tumbled 7% to Rs 1,302, and TCS has shed 6.7% at Rs 812.HDFC and ICICI Bank have plunged around 6% each to Rs 2,449 and Rs 786, respectively.Jaiprakash Associates has dropped 5% to Rs 228. Grasim, Reliance Energy, Satyam and DLF have slipped nearly 5% each to Rs 2,574, Rs 1,269, Rs 389 and Rs 663, respectively.Larsen & Toubro, Hindalco and ONGC have declined over 4% each to Rs 3,012, Rs 168 and Rs 1,010, respectively.Cipla is up over 1% at Rs 220.Out of 2,520 stocks traded so far, 1,374 have advanced, 1,097 have declined and the rest are unchanged.