> ...or prove sufficient sophistication that they really know what they're doing."

You could extend the standard by other ways which don't depend on how much one owns - e.g. require people to take a test and make sure they understand the basics of the product/ecosystem they are investing in.

Might also be useful to put up limits how much of your savings can be invested. But in a few $1000 play money is one thing, betting your entire life savings or your children's college fund is something else.

I see it similar to driver's licenses. A driver's license is technically discriminating in the sense that it excludes everyone physically or mentally unfit to drive a car. But it does so with good reason, because attempting to drive when you're really not able to do so can have catastrophic consequences.