I'm so glad Amarin was discussed here, and that I finally took the time to look over the trading it had...both before and after they announced Top-Line results.  The SA blog post I did already has over 700 views on it, and that's in just one day.

I'm not going to bother checking on what the social media/message board chatter was in the months prior to Sept 24 2018.  But one thing is clear to me....the trading leading up to their annoucment gave off no indications that success was imminent except perhaps to an ultra contrarian.  I suspect most shareholders were likely alarmed at the downward trend leading up to them announcing having met their primary end point.  

In fact I'm quite certain that some likely bailed out of fear, having seen the PPS for AMRN erode to less than $2.40 in late July after it had been over $4.50 in January.  

Looking at short interest for AMRN it looks like there was a real ramp up ahead of the news coming out....in May 2018 short interest was just about 4 million, then 5, 6, 7, all the way to 12 million by September 14th....a tripling in just 4 months or so.  Even now its 15 million, but against oustanding shares of almost 300 million its not a big % obviously.