The problem with AH and pre market is that the volume (relative to the huge volume during market hours) is puny. As a result you have an empty space when you look at volume by price. Once the bottom of such a space (the top of the gap) is taken, the closing usually is quite fast. Usually, means there are always exceptions. I think that WAVX hs a two month old gap by now, but I also think it will eventually close.