The Bombay Stock Exchange benchmark Sensex today bounced back by gaining 60 points in the opening trade. The 30-share index later lost some points and was trading at 20,883, up by over 7 points a short while ago. Analysts said the rise in Sensex is on the back of rally in banking, oil and gas, and metal stocks following fresh buying by funds amid firming global cues.In Asian markets, the Hong Kong's Hang Seng Index was up by 0.29 per cent and Japan's Nikkei Index by 0.39 per cent in morning trade. In the US, the Dow Jones Industrial Index ended 0.09 per cent up yesterday.