The Sensex at the Bombay Stock Exchange gained 54 points, or 0.3 per cent, to 17,544, in opening trade, today, on continued capital inflows by foreign funds. But the Sensex later surrendered all its early gains, and stood 39 points, or 0.2 per cent in the red, at 17,451, a short while ago.Stock markets in Japan, China, Hong Kong, Singapore, Indonesia and South Korea were down between 0.2 per cent and 1 per cent, today. The US Dow Jones Industrial Average had gained 0.5 per cent, overnight.