The BSE benchmark Sensex shot up by over 135 points to regain the magical 20,000-level in the opening trade today for the first time since January 17, 2008. The surge in the Sensex which is trading at 20,042 points follows spurt in buying of oil and gas, capital goods and banking sector stocks.All the sectoral indices were trading with gains up to 1.30 per cent.Similarly, the wide-based National Stock Exchange also crossed the crucial 6,000 points to trade 36.40 points higher at 6,016.85 points.Both indices have regained these levels after almost 32 months.