Full on ban of all stock ownership will never happen and is entirely unrealistic and performative on her part because she knows it will never happen.
The only thing that might ever have a snowball's chance in hell is to only allow Senators during their terms to put new money into a large publicly traded broad index fund. This allows them to continue investing like everyone else but they are now more beholden to the performance of the market as a whole and regular citizens can also easily make the the exact same investments as the politicians.
Again it will never happen either way, but a full ban on "stock ownership" is an utter joke, she might as well put on the clown hat.