The BSE benchmark Sensex gained 125 points in the opening trade today on fresh buying of heavy-weight stocks, driven by firming trend on the other Asian bourses. The 30-share index of the Bombay Stock Exchange, which had lost about 260 points in the previous two sessions, recovered by 125 points or 0.62 per cent at 20,426 level in the opening trade.Similarly, the broad-based National Stock Exchange index Nifty also moved up by 36 points or 0.60 per cent to 6,116 points.Brokers said fresh buying by funds and retail investors on firming trend in Asian markets, helped the Sensex recovery.Meanwhile, Japan's Nikkei Index rose by 0.93 per cent while Hong Kong's Hang Seng Index was up 0.05 per cent in the morning trade.In the US, the Dow Jones Industrial Index ended 0.27 per cent up yesterday.