Under "conditional", one can use a trigger to place an order with IB. E.g. if the price goes below $19, then that would trigger a buy-to-open order. IB allows you to define what "the $19" goes based on. Can anyone explain what it means "double last" , "double bid", and "bid/ask"? Note: i would like to go based on the ask price, and want to know how to apply it. Appreciated.