They’d be in court today if they were doing what you’re suggesting. In the US, anything designated as a retirement fund is only held my institutions (banks) that designate themselves as such, and SEC regulations prevent them from using any NON-CAPITAL cash from investing in this way.

You don’t have a goddamned clue what you’re talking about. We’re not talking about banks illegally investing people’s savings accounts; we’re talking about non-banks investing people’s retirement accounts that they’ve specifically been advised are not FDIC insured and can lose money. You’re confusing two very different things.

The bottom line is that it very much IS REGULAR PEOPLE’S MONEY that they’re using, NOT THEIR OWN MONEY! The fund managers themselves have no skin in the game. The owners of Blackrock itself (holders of individual shares in Blackrock, not Blackrock-administered mutual funds) have no skin in the game. The owners of Vanguard only have skin in the game because it’s got a weird corporate structure where it’s owned by its funds, but even then the money that Vanguard is investing didn’t come from Vanguard’s revenue; it’s all money that they’re handling on behalf of clients (i.e. regular people) who own shares in Vangaurd-administered mutual funds. It’s those clients who gain or lose money depending on the funds’ performance, not Vanguard or Blackrock – the fund companies just get revenue by charging fees (i.e. the expense ratio, etc.).