The Sensex opened with a positive gap of 121 points at 18,724, and after touching day's high of 18,745, the index soon slipped into red. The index, thereafter, exhibited highly volatile movement wherein it gyrated between zones and tumbled to a low of 18,183 - down 562 points from the day's high.Aggressive short covering towards the end, saw the Sensex rebound into the positive zone and end (provisional) with a gain of 49 points at 18,652.
