The Bombay Stock Exchange benchmark Sensex today opened over 68 points high at 19,760.The Sensex was trading at 19,741 up by 50 points when reports last came in.Brokers said buying at prevailing levels by funds and retail investors along with covering-up of short positions by speculators in view of tomorrow's monthly expiry in the derivatives segment, helped improve the trading sentiment. Meanwhile, in other Asia markets, Hong Kong's Hang Seng Index was up by 0.92 per cent, while Japan's Nikkei Index by shed 1.71 per cent in early trade. In the US, the Dow Jones Industrial Index ended 1.27 per cent down at yesterday's close.