The Sensex at the Bombay Stock Exchange rose 105 points, or 0.6 per cent, to 17,236 in opening trade, this morning, on fresh buying by funds and retail investors, amid positive Asian markets. But the Sensex later surrendered all its early gains, to stand 53 points, or 0.3 per cent in negative territory, at 17,078 in afternoon trade, a short while ago. Key stock indices in Japan, Hong Kong, Singapore and South Korea were up by between 0.3 percent and 0.5 percent, today, after the Bank of Japan unveiled fresh easing measures to support the Japanese economy. Over in the US, the Dow Jones Industrial Average had gained 0.9 per cent, overnight.