The Sensex at the Bombay Stock Exchange rose by 158 points in early trade today, on sustained buying by funds and retail investors, mainly in realty, banking, auto and metal sector stocks. In yesterday's session, Sensex had gone up by 31 points.The Nifty at the National Stock Exchange regained the 6,000 points level by surging 41 points, or 0.69 per cent, to 6,036.In the Asian region, Japan's Nikkei gained 2.123 per cent to trade at over five-year high as exporters rallied on the yen's sharp slide, while Hong Kong's Hang Seng rose by 0.39 per cent in early trade today.The US Dow Jones Industrial Average ended 0.82 per cent higher yesterday.