The Sensex at the Bombay Stock Exchange rose a modest 44 points, or 0.3 per cent, to 16,510 in early trade, today, on sustained buying by funds and retail investors. But later, the market turned volatile, and after moving in and out of the positive zone, the Sensex stood 11 points in negative territory, at 16,455 in afternoon deals, a short while ago. The 30-share Sensex had gained more than 420 points in the past three trading sessions.Other Asian markets in Japan, China, Hong Kong, South Korea, Singapore and Indonesia were trading mixed, today, ahead of a key meeting between Greece and its creditors. Over in the US, the Dow Jones Industrial Average had gained 0.5 per cent, overnight.