Really interesting discussion in the comments by experts on MLMs.
Loeb's HLF long case.
Ackman thinks the shares will go to zero because it is a fraud. HLF is a shitty company but it is not fraudulent. I expect Akman will be proven right in the long run, although I question whether he will be able to make it there.
And Carl Icahn gets long HLF - though the WSJ calls it a small position.