Mumbai: The BSE benchmark Sensex rose by over 76 points in opening trade today on the back of fresh buying by funds and covering-up of pending short positions ahead of monthly expiry in the derivatives segment tomorrow, which drove up stocks of certain companies. The 30-share index of the Bombay Stock Exchange (BSE) gained 76.37 points to 20,101.79 in the first few minutes of trade, with consumer durables, metals, technology and banking stocks leading the gains. A firming trend in the Asian region also influenced the trading sentiment here, market analysts said. Similarly, the wide-based National Stock Exchange Nifty index moved up by 21.90 points to 6,017.90. Brokers said selective buying of index-related stocks and covering-up of short positions by speculators ahead of monthly expiry in the derivatives segment tomorrow helped the Sensex rise. Meanwhile, Hong Kong's Hang Seng index was up 0.