Giving up all its initial gains, the Sensex at the Bombay Stock Exchange stood 40 points, or 0.2 percent in the negative zone, at 20,935 in afternoon trade, a short while ago. But earlier in morning trade, the Sensex had gained 48 points, or 0.2 percent, to 21,023, on fresh buying by funds.Stock markets in Japan, China, Hong Kong, Taiwan and Indonesia had climbed between 0.1 percent and 0.8 percent, today. The US Dow Jones Industrial Average had ended 0.1 per cent lower in yesterday's trade.