This is only true on technicality. While the SEC is a regulatory agency they are more-or-less in bed with the FBI who, to my knowledge, has never said "yeah we'

This is only true on technicality. While the SEC is a regulatory agency they are more-or-less in bed with the FBI who, to my knowledge, has never said "yeah we're not gonna go after that criminal" when they asked. So yes, de facto they cannot charge people with crimes. The reality is they basically just phone the FBI and the FBI does it for them. There's very little separation in powers especially after the chevron deference case.