Widespread optimism after the pro-growth union budget helped markets to rebound sharply in last three days while favourable global cues also supported the rally. The Sensex closed above the 50000-mark for first time ever. The 30-share index ended at 50,255.75, up 458.03 points or 0.92%. The Nifty closed at 14,789.95, up 142.10 points or 0.97%.