You'd have to prove negligence, which is practically impossible in this case - he bet on some technology, it didn't work out, that happens thousands of times all over. Also, I know this is not something you'd like to hear, but you are not entitled to be employed at any particular firm, and company owner does not owe you a fiduciary duty to continue your employment. Also, FB employees hardly could complain about being treated poorly - I heard 500k+ compensation packages for engineers aren't out of the ordinary there. Tell it to somebody who works in a factory for 50k and see if they would think you were mistreated, after earning more in you short while than some earn in their whole life.

> similar how a shareholder can sue for lost profits.

Only if there's negligence or fraud, which you have about zero chance to prove in this case.

> But honestly a business leader that screws up so bad, should probably loose all their wealth, like 100%.

Would you agree to lose 100% of you money each time you make a mistake? If not, why should he?