The stock had finally and deservedly exited its downward channel. It was starting to run and threatening to break out. With that momentum, even moderately good news at ESMO might mean the shorts never see $20 again.
Suddenly the new "short thesis" appears, predicting not just failure, but the early stoppage of EPIC for safety reasons. It's a dirty drug, don't you know.
Ridiculous though it was, in a nervous market, in a stock that's itself made a lot of people nervous this year, that was all they needed to get out alive.
When they put something like that together, it gets distributed in concentric circles. The first people they tell, their closest associates, it's to let them in on it. From there, it's a tough call whether they scare up more sellers from among those who think it may be true, or those who want to pile on, or just get out of the way because the shorts are attacking and the stock is going to get hammered for a few days. In either case, it doesn't matter to the end result.
Feurstein reporting it to the public is like day 4 of this process. Anyone who sells at that point is giving shares away. I think today ended it, and we get a strong couple of days into ESMO.