The BSE benchmark Sensex was trading 226 points up at 19,959 a shortwhile ago. The 30-share index gained 293 points in opening trade today, mainly on the back of a flurry of buying by funds and investors. It had lost over 265 points in the previous two sessions.The wide-based National Stock Exchange index Nifty was also trading 59 points up at 5,910 in late morning deals.