alt Hacker NewsBecause people with titles of nobility were forbidden from participating in business at the risk of losing their titles; projecting to modern era, they'd be also forbidden from owning stocks at all. They must derive their means of existence from land rents and public/military service. Pretext was that engaging in commerce or business was "dishonourable" and below their status, in practice, it was a useful tool to avoid conflict of interest.
To think of it, there's something tempting in physically separating owning class from ruling class, isn't it?
I find all this rather flaccid, frankly. While the advent of capitalism provided an avenue for non-titled people to become wealthy, a lot of titled people also took that opportunity and I would guess a lot of generational wealth today still finds its ultimate source in entitled people.
In any case, I doubt society could successfully enforce this behavior in a contemporary context.