Maintaining its initial gains, the Sensex at the Bombay Stock Exchange stood 90 points, or 0.5 percent in positive territory, at 19,992, amid volatile trade, a short while ago. Earlier, in morning deals, the Sensex had added 61 points, or 0.3 percent, to 19,963, with auto, consumer durables, IT and realty sector stocks climbing on expectations that economic growth will improve in the second half of this fiscal. The Sensex had rallied over 520 points in the previous two trading sessions. But stock markets in Japan, Hong Kong, Singapore, South Korea and Indonesia had lost between 0.1 percent and 0.9 percent, today, as concerns grew over the US political impasse. Wall Street's Dow Jones Industrial Average had ended 0.9 per cent lower in yesterday's trade.