Giving up all of its initial gains, the Sensex at the Bombay Stock Exchange stood 57 points, or 0.3 percent in negative territory, at 20,434 in afternoon trade, a short while ago, on fresh selling by funds and retail investors. Earlier in the morning, however, the Sensex had climbed 93 points, or 0.5 percent, to 20,584. The Sensex had lost 748 points in the previous five trading sessions.Stock markets in Japan, China, Taiwan, South Korea,Singapore, Hong Kong and Indonesia were trading mixed, today. The US Dow Jones Industrial Average had ended 0.1 per cent higher in yesterday's trade.