The Sensex at the Bombay Stock Exchange lost some more ground in afternoon trade, to stand 159 points, or 0.8 percent in negative territory, at 21,096 a short while ago. Earlier in the morning, the Sensex had declined 90 points, or 0.4 percent, to 21,165, as foreign funds and retail investors booked profits, amid weakness the the global bourses. Elsewhere in Asia, stock markets in Japan, China, Taiwan, South Korea, Indonesia, Singapore and Hong Kong had lost between 0.5 percent and 1.4 percent, today, on concerns about the US Federal Reserve, or central bank, tapering its monetary stimulus.The US Dow Jones Industrial Average had ended 0.3 per cent lower in yesterday's trade.