The Sensex opened with a huge negative gap of 425 points at 14,675, and dropped 530 points to a low of 14,570 in opening deals.The index is now down 423 points at 14,677.ITC has plunged over 4% to Rs 157.ICICI Bank and HDFC Bank are down nearly 4% each at Rs 855 and Rs 1,112, respectively. SBI is down 3.6% at Rs 1,592.Reliance has slipped nearly 3% (Rs 52) to Rs 1,790.Tech, auto and telecom scrips are also trading with steep losses.