The Sensex at the Bombay Stock Exchange rose 139 points, or 0.7 percent, to 19,814 in early trade, today, on fresh buying by funds, tracking firm Asian markets.But later the Sensex turned volatile, and after see-sawing between gains and losses, it stood a more modest 33 points, or 0.2 per cent in positive territory, at 19,707 in afternoon trade, a short while ago. The 30-share Sensex had lost over 610 points in the previous four trading sessions.Stock markets in Japan, China, South Korea and Indonesia had gained between 0.2 percent and 0.9 percent, today. The US Dow Jones Industrial Average had ended flat in yesterday's trade.