The BSE benchmark Sensex shot up by 293 points in opening trade today, mainly on the back of a flurry of buying by funds and investors. The 30-share index gained 293 points to trade at 20,026 with banking, capital goods, PSUs and power sector stocks leading the rally. It had lost over 265 points in the previous two sessions.The wide-based National Stock Exchange index Nifty rose by 82 points to trade at 5,933.Brokers said sentiments turned buoyant after SEBI allowed FIIs to invest in government securities without any auction mechanism so as to boost foreign fund inflows into the capital markets. In the Asian region, Hong Kong's Hang Seng index rose by 1.47 per cent in the opening trade, while Japan's Nikkei would remain closed today. The US Dow Jones Industrial Average ended 0.49 per cent higher on Friday.