The BSE benchmark Sensex gained over121 points in early trade today on emergence of buying by funds and retailers amid a firming Asian trend.The 30-share barometer gained 121.41 points, or 0.61 per cent, to 19,902.60. The index had lost almost 224 points in the previous two sessions.Similarly, the wide-based National Stock Exchange index Nifty moved up by 39.60 points, or 0.66 per cent, to 6,038.50.Meanwhile, in Asia, Hong Kong's Hang Seng index rose by 0.53 per cent, while Japan's Nikkei up by 0.81 per cent in early trade. The US Dow Jones Industrial Average ended 1.08 per cent higher in previous session on Friday.