The Sensex at the Bombay Stock Exchange lost 47 points, or 0.3 per cent, to 16,729 in opening trade, today, as investors continued to off-load stocks, amid disappointing second quarter corporate earnings, subdued global markets, and persisting concerns about the Euro-zone debt crisis.After recovering to briefly move into the positive zone, the Sensex again lost ground, and stood 52 points, or 0.3 percent in negative territory, at 16,724, in afternoon trade, a short while ago.The 30-share Sensex has already lost nearly 800 points in the past five trading sessions. Other Asian markets in Japan, China, Hong Kong, Singapore and South Korea were trading mixed, today.Over on Wall Street, the Dow Jones Industrial Average had lost 1.6 per cent in yesterday's trade, after global ratings agency, Fitch warned that US banks could be hit hard by the euro zone crisis.