The Sensex opened with a positive gap of 30 points at 11,969. Fresh buying in the morning deals saw the index zoom past the 12,000-mark to touch a high of 12,087.However, persistent selling at higher levels capped the upmove. The selling gained momentum in latter half of the day as a result the index tumbled into red all the way to a low of 11,803 - down 284 points from the high.The index finally ended with a loss of 104 points at 11,835.