Financial markets completey abstracted risk of investment and wealth accumulation from the real economy. That capital concentration will somehow correct itself because the rich make the wrong investments in the markets is disproven by reality to a degree that you have to really go out of your way to ignore it.
It will obviously correct itself, but not because of choices people make in the market, but because more and more money is syphoned out of the economy into financial assets, which decreases demand in the real economy, which will eventually lead to a complete collapse of it, followed by civil unrest, a lot of horrible shit, the rich hanging from the street lanterns again, etc.