After a weak opening, the Sensex at the Bombay Stock Exchange later lost further ground, and after plunging well over 500 points in early afternoon trade, stood 460 points, or 2.3 per cent in the red, at 19,497, a short while ago. Earlier this morning, the Sensex had dropped 218 points in opening trade. Stocks fell on profit-booking and as weak Asian and European bourses weighed on investor sentiment. In other Asian markets, key stock indices in China, Hong Kong, Singapore and South Korea were down by between 0.8 per cent and 2.5 per cent, today. Over in the US, the Dow Jones Industrial Average had shed 0.2 per cent in Monday's trade.