The Sensex opened marginally (12 points) higher at 14,200, and rallied to a high of 14,287 in early deals. However, sustained selling pressure at higher levels saw the index pare gains and displayed lacklustre movement for the major part of the trading session.A heavy bout of selling in late noon deals saw the index plunge to a low of 13,978 - down 309 points from the day's high.The Sensex finally settled with a loss of 167 points at 14,021. The index has dropped 382 points in the last three trading sessions.The BSE Bankex declined 2.5% to 6999. The Auto and Healthcare indices were down around 2% each to 5459 and 3709, respectively.The market breadth was negative - out of 2,683 stocks traded, 1804 declined and 820 advanced today.AND THEY ALL FELL DOWN....Grasim plunged over 5% to Rs 2,416. ACC shed 4% to Rs 964, and Gujarat Ambuja crumbled 3% to Rs 127.Ranbaxy slipped nearly 4% to Rs 368, and Hero Honda tumbled over 3% to Rs 716.HDFC Bank, Dr.Reddy's, SBI and Maruti declined around 2.5% each to Rs 989, Rs 711, Rs 1,080 and Rs 879, respectively.Wipro, Cipla, ICICI Bank, Tata Motors, Bajaj Auto, ONGC, HLL and Reliance Energy were the other major losers today.Reliance Communications, however, was up nearly 1% at Rs 451.FIRSTSOURCE - FIRST DAY, GREAT SHOWFirstsource debuted on the BSE at Rs 75 as against its issue price of Rs 64. Unabated buying at the counter saw the stock zoom to a high of Rs 89 before settling with a smart premium of 25% (Rs 16) at Rs 80 on its first trading day.MOST ACTIVE COUNTERSFirstsource topped the value chart with a turnover of Rs 235.65 crore followed by Global Broadcast (Rs 190 crore), HDFC Bank (Rs 178.60 crore), Reliance (Rs 145.44 crore) and Aptech (Rs 140.40 crore).Firstsource also led the volume chart with trades of around 2.90 crore shares followed by Zee News (1.46 crore), IFCI (1.45 crore), Aptech (55.92 lakh) and Reliance Natural Resources (38.37 lakh).