The Sensex rallied about 148 points to 27,856 in early session today, maintaining its positive form for the fourth day as the February derivatives series took off on a strong footing amid positive Asian cues.
The 30-share Sensex, which gained 673.64 points in the previous three straight sessions, added 147.57 points, or 0.53 per cent, at 27,855.71. All sectoral indices of BSE led by oil and gas, power and PSU were in the positive zone, rising by up to 1.34 per cent. The NSE Nifty jumped 40.75 points, or 0.47 per cent, to 8,643.50.