It means that you can keep those shares even if you leave. Otherwise the term vesting cliff would be meaningless at any startup where the shares are not liquid.

They are yours. That’s a huge difference between a real cliff and illiquid stock.

If you decide you don’t like it, you take what’s vested after the cliff and leave. Even if you have to wait another year and a half to sell, you still got the gain.

Massive difference. You can vest and move on, even if you don’t have liquidity, which most private companies don’t for employees anyway.

Except you can only sell a prescribed amount at an undetermined time. By the earliest possible sell date you have already made 8 figures liquid at Meta.

Ok, but that’s a trade off anyone who works for a private company makes, and it’s never called an “effective cliff”.

Ok fine, 8 figure opportunity cost if that makes you feel better.