The Sensex at the Bombay Stock Exchange opened 80 points, or 0.4 per cent higher, at 18,129, this morning, tracking firm Asian markets. Remaining firm, the Sensex stood 65 points, or 0.4 percent in the green, at 18,114, a short while ago. The stock market in Japan was up 1 per cent, while in Hong Kong, it was up 0.4 per cent today. The US Dow Jones Industrial average had gained 1 per cent overnight.