[eru]

> You can always sell your grant as you get it, they can’t make holding stock mandatory, [...]

They can. It's easy in private companies to limit what an employee can do with their stock, and in public companies they can insert a clause in the contract to that effect just fine. Or just have very long vesting periods.

(Of course, as a would-be employee I would take these restrictions into account when deciding where to work.)

[seanmcdirmid]

You either own the stock or you don’t. If you paid federal income taxes on it, they have to let you sell it as you get it if you want, otherwise it isn’t real income. They can restrict when you sell it afterwards, but only in the cause of avoiding insider trading, and you can set up a plan to sell it blindly if you’d like.

[eru]

It's not nearly as simple as that.

Look up eg a 'poison pill' for an example where you don't "either own or stock or you don't". (See https://en.wikipedia.org/wiki/Shareholder_rights_plan)