The Sensex gained over 38 points in the opening trade today to trade at 20,581.Foreign Institutional Investors kept pumping money into equity markets after International Monetary Fund said India's economy will expand by 9.7 per cent in 2010. The index had gained 135.37 points in the previous session.The wide-based National Stock Exchange index Nifty moved up by 11.35 points to 6,197.80 points.In Asian markets, the Hong Kong's Hang Seng Index gained 0.28 per cent, while Japanese Nikkei was down by 0.31 per cent in the morning session. In the US, Dow Jones Industrial Average ended 0.21 per cent higher yesterday.