The Sensex opened with a huge positive gap of 92 points at 20,393, but dropped to a low of 20,077 in morning deals.Heavy buying in select heavyweights like ICICI Bank saw the index hit an all-time high of 20,529 in noon deals - an intra-day swing of over 450 points.The Sensex finally closed with a gain of 164 points at 20,465.The BSE Bankex zoomed over 3% ( 360 points) to 11,870.. The BSE Realty Index gained 3% to 13,420. The BSE Smallcap and Midcap indices finished with gains of over 1% each today.Market breadth was bullish - out of 2,948 scrips traded, 2,007 logged gains today.INDEX GAINERSHDFC led the rally with a gain of nearly 5% (Rs 139) at Rs 3,057.Tata Motors finished up 4% (Rs 31) at Rs 794.ICICI Bank moved up nearly 3% (Rs 35) to Rs 1,266. SBI added 1.5% (Rs 35) to Rs 2,421.Reliance Energy gained nearly 4% (Rs 86) to Rs 2,365.Reliance was up Rs 15 at Rs 2,862. Cipla was up 3% at Rs 219. ONGC, Ranbaxy, DLF, ITC, Maruti and NTPC also closed with gains today. ....AND LOSERSSatyam was down 1.6% at Rs 436. Wipro and TCS also slipped today.BHEL declined 1% to Rs 2,550. M&M, RCom and ACC also declined.MOST ACTIVE COUNTERSRNRL was the most active counter with a turnover of Rs 476 crore followed by Reliance Energy (Rs 230 crore), Essar Oil (Rs 194 crore), UCO Bank (Rs 189 crore) and Reliagare (Rs 178 crore).