Nifty on Wednesday formed a long negative candle with a lower shadow on the daily charts, indicating support-based buying despite pressure at high levels. Now, it has to hold above 18,181 zones to witness an up move towards 18,333 and 18,400 zones, while on the downside supports are placed at 18,081 and 18,018 marks. Chandan Taparia of Motilal Oswal said India VIX was down by 1.39% from 13.