The Sensex opened with a huge negative gap of 300 points at 17,260, and dropped to a low of 17,171 in early trades.Buying at lower levels saw the index recoup all the losses, and zoom to a high of 17,705 - an intra-day gain of over 500 points.After exhibiting extreme volatility in late noon deals, the Sensex finally closed with a gain of 54 points at 17,614.The BSE Bankex gained over 2% (191 points) to close at 9029. The BSE FMCG and Capital Goods indices also closed with gains. The BSE Oil & Gas Index declined 1.6% (162 points) to 10,080. The BSE Teck, PSU and Realty indices also dropped today.Advances and declines were evenly matched - out of 2,754 scrips traded, 1,344 advanced and 1,339 declined.INDEX GAINERS...HDFC zoomed over 7% (Rs 174) to Rs 2,572. ICICI Bank moved up over 3% to Rs 1,062. SBI added nearly 3% to close at Rs 1,713.While Ambuja Cements gained over 4% at Rs 145, M&M added 3.6% at Rs 754.Reliance Energy, ACC, L&T, Hindalco and ITC also finished with gains today..... AND LOSERSBharti slipped over 4% (Rs 41) to Rs 928.TCS declined nearly 3% (Rs 32) to Rs 1,074. Infosys, Satyam and Wipro also dropped today.Reliance was down over 2% (Rs 56) at Rs 2,413.MOST ACTIVE COUNTERSAmbuja Cements was the most active counter with a turnover of Rs 809 crore followed by Reliance Energy (Rs 553 crore), United Breweries (Rs 509 crore), Reliance (Rs 480 crore) and Reliance Communications (Rs 235 crore).