The Sensex at the Bombay Stock Exchange dropped 192 points, or 1 per cent, to 18,417 in opening trade today, on profit-booking by investors after two days of gains, and in line with weak global markets. Later the Sensex remained subdued, and stood 123 points, or 0.7 percent in negative territory, at 18,486 in afternoon deals, a short while ago. The 30-share index had gained more than 370 points in the last two trading sessions.Other Asian bourses in Japan, China, Hong Kong, Singapore, South Korea and Taiwan were down by between 0.5 percent and 2 percent, today, after some very weak US economic data raised questions about demand for Asian exports. Over in the US, Wall Street's Dow Jones Industrial Average had slumped 2.2 per cent in Wednesday's trade.