The Sensex, from an all-time intra-day high of 17,953, plunged to a low of 17,288 - down 665 points in little over an hour. The index is now up 109 points 17,438.Infosys and HDFC have surged 3.7% each to Rs 1,965 and Rs 2,600, respectively.TCS and Wipro have rallied 2% each to Rs 1,060 and Rs 463, respectively.Reliance Energy has plunged 7.4% to Rs 1,250. SBI has slumped 5% to Rs 1,800.Cipla and Tata Steel have dropped 4% each to Rs 181 and Rs 809, respectively.Ranbaxy and ACC have slipped nearly 3% each to Rs 428 and Rs 1,176, respectively.Tata Motors, Maruti, Dr.Reddy's and Reliance Communications are the other major losers.Out of 2,767 stocks traded so far, 1,868 have declined, 844 have advanced and 55 are unchanged.