I understand your point but it depends on the timeline. It's actually appreciated way less than most of the sector and peers over the last 2-3 years (which has been on fire). There is no way a drop from $20.25 to $6 a share was justified. This current market cap makes way more sense relative to stocks like SGEN.
Biotech is crazy and leading the market right now. You don't want to be on the wrong side of a biotech whether up, or down. It's possible to have little explanation or sense to biotech moves. Also I think there are more than the 2 possible scenarios you pose, for an explanation for the run, if there is one.