I guess he got people to buy a lot, and now he's trying to get them all to sell at once.
He also tweeted his recommendation to sell YKW and Matthew Herper, neither of whom have been positive about DCVax. They seem to be in sync on their view on NWBO, both YKW and Matthew Herper, though many people include Herper on their tweets, so there is some sense that he is more objective potentially than YKW.
He tweeted about it the first time in August, with incredibly optimistic posts.
Now he's pessimistic and an expert on Direct, not L. Something doesn't add up there. I think he did not know what he was buying given his predictions at the start. I think he's jumping from extreme conclusion to extreme conclusion. That's not uncommon for people who don't get to know a stock before they buy it, watch it go down and then freak out. I don't think this is meaningful at this time. He has no special information and he's a cardiologist, not an expert in this field.