Giving up all its initial gains, the Sensex at the Bombay Stock Exchange stood 160 points, or 0.8 percent in negative territory, at 19,837 in afternoon trade, a short while ago. Earlier, in morning trade, the Sensex had gained 55 points, or 0.3 percent, to 20,052, on buying by funds and retail investors ahead of industrial output data, and amid further strengthening of the rupee. The Sensex had had rallied over 1,750 points in the previous five trading sessions.Stock markets in China, Indonesia, Taiwan, South Korea and Singapore had added between by 0.1 percent and 1 percent, today. The US Dow Jones Industrial Average had ended 0.9 per cent higher in yesterday's trade.