The BSE benchmark Sensex which has lost 1,133 points in the previous eight straight sessions, rebounded by 51 points, to 18,520 in opening trade.Similarly, the wide-based National Stock Exchange Nifty index also moved up by 12 points, to 5,549 points.Meanwhile, Hong Kong's Hang Seng Index shed 0.44 per cent in early trade today. The Dow Jones Industrial Average in the US market ended 0.66 per cent lower in Wednesday's trade.