If you're trading CFD's it's even more centralized than buying a basket of shitcoins. Some brokers that allow you to buy stocks and whatnot present their platform very well, but you don't own the right to anything. People skip the TOS and click agree to all terms faster than you can blink with your eye.
it's a reasonable middle ground. real stock ownership demands national securities exchange registration, KYC, all sorts of regulatory nonsense. CFDs are much more of a grey area. people dumping their bitcoins into other investments don't care about stock voting rights and things like that anyway. they're just in it for quick profits.
Even if the possibility was there, I wouldn't put a single one of my satoshis into a hyper inflated US stock market. Look at the Nasdaq and Dow Jones index charts, that's not a bull market anymore, but a dinosaur market. In all honesty, I consider buying US stocks at this stage more risky than buying Bitcoin. It's the biggest bubble mankind has ever witnessed.
i've been hearing people say that for the last decade. meanwhile, the market has risen 500% since then. is it insane, irrational exuberance? sure! and none of us knows where it'll end.