[gwnywg]

Wow... so you have to pay tax on money you actually don't have in your wallet yet? This would be a bit of bonkers since, in fact, you may never get to the point when you get real money from your shares... Can US citizens do anything to pay when they actually get money on their bank account (i.e. when they liquidate their shares) and not before?

[vorador]

Yeah – you're exactly right. This is because a relatively obscure tax called the AMT (https://en.wikipedia.org/wiki/Alternative_minimum_tax) often kicks in when you exercise your options.