The Sensex at the Bombay Stock Exchange rose 131 points, or 0.8 per cent, to 17,234 in opening trade, this morning, on fresh buying by funds and retail investors, amid firm regional bourses. But the Sensex later trimmed much of its early gains, to stand 42 points, or 0.2 per cent in the green, at 17,145 in afternoon deals, a short while ago. The 30-share Sensex had lost 515 points in the last four trading sessions.Stock markets in Japan, China, Singapore, Taiwan, South Korea, Hong Kong and Indonesia were up by between 0.2 percent and 1.5 percent, today, as investors hoped that US central bank chairman Ben Bernanke will indicate fresh policy-easing moves in his semi-annual testimony to the US Congress.The rupee trimmed early gains against the dollar, but was still stronger by 36 paise at 54 rupee 95 paise. It was due to the selling of American currency by banks and exporters, coupled with continuing capital inflows.The dollar also lost some ground against other currencies in the overseas markets.The rupee , in its opening session had resumed higher at 54 rupee 89 paise a dollar as against the yesterday's closing level of 55.31.