Are fake reddit bucks a real security? I'm not convinced anything illegal happened here. Even Reddit itself is not publicly traded so I don't think there's a case to be made for material non-public information.
Even if they aren't securities, a rug-pull of any medium of exchange ("reddit bucks") would fall under wire fraud. https://www.justice.gov/archives/jm/criminal-resource-manual...
> the four essential elements of the crime of wire fraud are: (1) that the defendant voluntarily and intentionally devised or participated in a scheme to defraud another out of money; (2) that the defendant did so with the intent to defraud; (3) that it was reasonably foreseeable that interstate wire communications would be used; and (4) that interstate wire communications were in fact used
The moment the seller knows that the tokens they are selling have taken a big hit to their value, they are engaging in parts 1 and 2 above when they attempt to sell the tokens to those ignorant of this hit in value. Parts 3 and 4 are guaranteed with internet architecture.
If this doesn't fall under the SEC's authority, they can easily send it on to the FBI.