SGEN has a very large short interest. The biotechs tend to be strong in the Dec/Jan period and the group is on a run.
So,prudent shorts probably have been covering. The reported short interest was down slightly mo/mo as of 12/31. However, the advance in SGEN has not been so steep that I would say that we have a squeeze, at least, not yet.
I would add on any pullback, as a squeeze could develop.