Giving up all its initial gains, the Sensex at the Bombay Stock Exchange stood 157 points, or 0.8 percent in negative territory, at 19,413 in afternoon trade, a short while ago.Earlier in the morning, however, the Sensex had opened with a good gain of 99 points, or 0.5 per cent, at 19,670, amid hopes of a rate cut by the Reserve Bank, next week, and rising regional bourses.Stock markets in Japan, China, Hong Kong, Indonesia and Singapore had gained between 0.7 percent and 1.4 percent, today, on positive US economic data. The US Dow Jones Industrial Average had added 0.6 per cent in yesterday's trade.