> "Market manipulation" itself is not necessarily illegal, if you just mean doing things that will effect the market in a way to bring profit to yourself.
I’m not quite sure what you mean by this. Market manipulation is a concerted (and sometimes coordinated) effort to artificially influence the supply or demand of a security. Market manipulation often relies on false information but false information is not at all a required element of market manipulation.
Where things get interesting (and fuzzy) here that I’m not quite sure where the line is between a group working together to influence the market and just... the market. I suppose its theoretically possible for everyone in the market to coordinate against one or a few players. To my knowledge there’s never been a situation with such a large coordinated effort.
That said, there are definitely a handful of individuals on WSB who got the ball rolling and have profited heavily. I definitely think the SEC could make the case they've violated the Exchange Act and potentially the '33 Act depending on what % of $GME the group controlled.