For example, Citadel can have a $0 balance, but purchase people’s stocks. Artificially raise market prices themselves. Then dump on everyone. All without another buyer…
No, requires a level of conspiracy that assumes: - so much more competence than exists, - that all the people Citadel routinely churn through don’t love money that the SEC will give them
They can, because the systems we built don't offer protection against the possiblity. They self report their trades. The better question is if they do.