The Sensex at the Bombay Stock Exchange gained 66 points, or 0.3 percent, to 19,758 in early trade, this morning, on selective buying by funds. Later, the Sensex stood 73 points, or 0.4 per cent in positive territory, at 19,765 in volatile afternoon trade, a short while ago.Stock markets in Japan, China, Hong Kong, Taiwan, South Korea and Singapore were trading mixed, today. The US Dow Jones Industrial Average had ended 0.2 per cent lower in yesterday's trade.