The Sensex at the Bombay Stock Exchange rose by 53 points in early trade today, extending its previous session's rally on sustained buying by funds and retailers largely on expectations of further economic reforms by the government.The 30-share barometer, which had gained 183 points on Friday, rose further by 0.28 per cent, to 18,815.The Nifty at the National Stock Exchange moved up by 10 points or 0.17 per cent, to 5,713.Meanwhile, Japan's Nikkei was down by 0.62 per cent in early trade today.