The BSE benchmark Sensex fell by 125 points in opening trade today. The 30-share BSE index, which gained over 361 points in the previous two sessions, declined by 125 points, or 0.77 per cent, to 16,050.86 in opening trade.In a similar fashion, the wide-based National Stock Exchange Nifty index shed 31.65 points, or 0.65 per cent, to 4,829.30.