Usually? Please ...

That's called insider trading and those who do that ends up in jail or at best have to hide in the sun for the rest of their life.

A recent example would be Intel's CEO Brian Krzanich dumping as much stock as he could after learning about Meltdown and before the news went public.

https://arstechnica.com/information-technology/2018/01/intel...

The article also cites Equifax's CEO selling before the news of their data breach went public.

And that's just the ones that are prominent enough that everybody knows about it.

Even just the routine sell off ten percent a year or whatever a financial planner would advise is something one can't do with your 401k.

There's of course legal ways to do similarly. I thought this was a good example of John Krafcik's resignation which to a certain extent meets the same aim:

Official resignation letter:

https://blog.waymo.com/2021/04/capstone-of-my-career-email-f...

"Interpreted" letter:

https://gist.github.com/ChuckM/ff5fc8c800c7fe9160483b68ec45a...

Is "hide in the sun" an idiom I'm unfamiliar with? Genuinely curious about what this means

Not OP, but I take it to mean that they flee to a tropical country with limited extradition laws.