The Sensex at the Bombay Stock Exchange rose 44 points, or 0.3 per cent, to 17,875 in early trade, today, on sustained buying by funds and retail investors.Later, the Sensex turned volatile, and after swinging between positive and negative territory, stood 154 points, or 0.9 percent in the negative zone, at 17,677 in afternoon deals, a short while ago. The 30-share Sensex has gained over 200 points in the past two trading sessions.Other Asian markets in Japan, Singapore, Hong Kong, Indonesia, Taiwan, and South Korea were down by between 0.2 percent and 1.6 percent, today, after Greece approved a long-awaited austerity agreement, but international backers called for ratification of the reforms before more bailout funds are released. Over in the US, the Dow Jones Industrial Average had ended 0.1 per cent higher, overnight.