MUMBAI, DEC 6: Ignoring the warning of the Securities and Exchange Board of India, operators continued their excessive speculation and pushed up share values and indices to dizzy heights on Monday. With speculators going overboard in infotech shares, as many as 17 scrips from the sector hit the circuit breaker and trading was suspended after prices jumped by the permissible 8 per cent limit. The benchmark Sensex shot up by 122 points and scaled the 4,800 mark in the speculative buying exercise.Cement and bank shares also followed software shares and gained substantial ground. Infotech shares like Satyam and Pentafour again led the list of highly traded shares. Leading infotech gainers were CMC Ltd (up Rs 40.75 at Rs 550.75, NIIT (Rs 181.15 at Rs 2,446.15), Silverline (Rs 50.50 at Rs 682.20), Aftek Infosys (Rs 88.60 at Rs 1,196.80 and Polaris (Rs 85.60 at Rs 1,156.15).Market regulator SEBI had last week asked the country's stock exchanges to keep a wary eye on the booming market. The warning comes closeon the heels of the sharp rise in the prices and volumes of infotech shares on the market. As much as 60 per cent of stock exchange's aggregate turnover is now driven by technology and infotech stocks, up from less than 30 per cent a year ago and two per cent five years ago, when only three IT companies - Infosys Technologies, Wipro and Tata Unisys - were actively traded on India bourses. ``Stock exchanges have not done anything to reduce the volatility in software stocks,'' said a fund manager.The sentiment was also boosted by record gains in US stocks on Friday and hopes of economic reforms speeding up after the lower house of parliament approved the opening up of the insurance sector last week. Most of the bank shares were in limelight on speculative buying. Cement scrips also joined the buying bandwagon on reports that the production of cement had risen by over 18 per cent for the first eight months (April-November) of the current financial year 1999-2000 over the same period of the previousyear.``Foreign investors have also added to the software rally. Many of the software stocks now seem to be overpriced. The huge volatility in software stocks is dangerous,'' said BSE broker BV Shah. Media company Zee Telefilms made a strong showing on the BSE where it traded for the first time with its new face value of one rupee per share. Earlier, each share had a face value of Rs 10. Zee's share jumped Rs 52 to Rs 702.50.Figures from India's market regulator SEBI showed foreign funds made net purchases of Indian equity worth $293.2 million in November, after being net sellers in the previous three months. The funds have kept up their purchases in December, buying a net $40.7 million in the first two days of December. Sensex opened higher by 70 points from the Friday's close of 4785.06, scaled further high to touch the day's high of 4842.34, fell below the 4800 mark and touched the day's low of 4785.06 points, before closing at 4835.98, showing a net gain of 121.84 points.