The BSE benchmark Sensex lost nearly 120 points in opening trade today. The 30-share barometer, which had gained 195.49 points in the previous session, fell by 119.88 points to 18,411.40 within the first few minutes of trade, with auto, banking, metals and realty sector stocks coming under pressure. Similarly, the wide-based National Stock Exchange Nifty index declined by 35.15 points to 5,509.60 points.