The Sensex at the Bombay Stock Exchange shed 99 points, or 0.6 per cent, to 17,856 in opening trade on Monday, on profit-booking by investors, and amid weak Asian markets. After rebounding from its lows, the Sensex stood one point in the green, at 17,957, in choppy trade, a short while ago.Other Asian markets in Hong Kong, Taiwan, Indonesia and South Korea were down by between 0.2 percent and 0.8 percent on Monday, after US consumer confidence weakened, and some corporate results fell short of expectations. The US Dow Jones Industrial Average had slumped almost 2.5 percent on Friday.