The Sensex at the Bombay Stock Exchange rose 116 points, or 0.7 per cent, to 15,980 within the first five minutes of trade, on Wednesday morning, on fresh buying in fundamentally strong stocks available at attractive lower levels. But later, the Sensex surrendered all its early gains, to slip 92 points, or 0.6 percent into negative territory, at 15,772 in afternoon deals, a short while ago. The 30-share Sensex has already lost more than 830 points in the past three trading sessions. Other Asian markets in Japan, South Korea, Taiwan, Indonesia, Malaysia, and Singapore were trading mixed, today. But over on Wall Street, the Dow Jones Industrial Average had ended 1.4 per cent higher, overnight.