The Sensex opened almost flat at 12,006, down four points. The index, however, soon surged to higher levels. Fresh buying in opening trades saw the index rally to a high of 12,115.The index, however, then lost momentum and exhibited range-bound movement for rest of the day. FMCG and pharma stocks were in demand, while metal and oil & gas indices witnessed selling pressure.The Sensex finally settled with a gain of 62 points at 12,071. The index has gained 4.5% (520 points) in the last five trading sessions following last Monday's 368 point sharp fall.