The Sensex at the Bombay Stock Exchange rose 39 points, or 0.2 per cent, to 18,568 in opening trade, this morning, on continued buying by funds and retail investors, amid firm Asian bourses. Later, the Sensex gained further ground, and after rising more than 150 points at one stage, the benchmark index stood 115 points, or 0.6 percent in positive territory, at 18,644, in afternoon deals, a short while ago. The 30-share Sensex has already gained about 320 points in the last two trading sessions. Stock markets in Japan, China, Indonesia and Singapore were up by between 0.2 percent and 0.4 percent, today. Over in the US, the Dow Jones Industrial Average had ended 0.4 per cent higher, overnight.