Maybe, but Job's still doesn't get paid a wage if I recall correctly meaning he wouldn't be overly liquid unless he has cashed in a fair amount over time.
No expert but wouldn't it depend on the scale of what he wanted to take out. Say for example Job's attempting to take a billion dollars off the table would have to effect the share price.
And this matters because?? I've heard Larry Ellison is the most illiquid billionaire, as he finances everything with loans against his massive equity in Oracle. He's still in the top 5 richest people. Zuckerberg is no different.