Last I checked, there is no fundamental legal barrier preventing this - just an enormous amount of compliance work that has to get done. But as we would be the only real option for 1 or 2 million well-monied people, I imagine we'd be able to start with a very eager customer base provided we could jump through those hoops. And uh, the actual algorithms for index based stock selection are pretty straightforward, too - I'm not Jane Street level clever, so that's an attractive point for me.
If anyone's interested in this hare brained scheme, let me know via the email in my bio. It's been a problem I've been rolling around in my head for a few years now. I have no idea how I would get started, but I'm pretty sure I could do it.