"Working" means a lot of different things, doesn't it?
I assume most rich people keep "working" at increasing the value of their investments. I mean, capital gains are taxed at a lower rate than wages, so if you've got the choice, you'd "work" at increasing capital gains, not at getting more wages.
How does one "work" at increasing capital gains? You increase capital gains by increasing how much you have invested. Which requires working a job in order to receive income that can then be invested.
I believe you can buy and sell stocks at will, unless you're an insider like a CxO or VP or even a director of a company. That's not most people.
So: selling stocks when you think they're near a high in price, and using the proceeds to buy other stocks when you think they're near a low in price. I expect the research to do this is time consuming.
It takes a lot of work to find the right projects to invest money into...or if even less hands off then the right financial advisor to put their money with. Most "rich" people don't just sink their money into a ETF or mutual fund and call it a day.
I assume most rich people keep "working" at increasing the value of their investments. I mean, capital gains are taxed at a lower rate than wages, so if you've got the choice, you'd "work" at increasing capital gains, not at getting more wages.