The Bombay Stock Exchange benchmark Sensex fell by 173 points in the opening trade on Friday. The 30-share Sensex, which had lost 101 points in the previous trading session, plunged 173 points, or 1.06 per cent to 16,154 points. The wide-based National Stock Exchange index Nifty shed 68 points, or 1.40 per cent to 4,819 points. The Hong Kong's Hang Seng index was down nearly 2 per cent, while Japan's Nikkei shed 0.74 per cent in the morning trade today.