b/c you can sell them at that point, the shares today are illiquid and they'd probably have to do something like a prepaid variable forward to be able to afford to exercise and pay tax (~23% of FMV - strike price) we're talking millions of dollars for early employees who didn't do an 83b election.

once airbnb IPOs they could do either of the following:

* Cashless (exercise and sell to cover: sell enough of your shares to cover the purchase price and applicable fees and taxes.

* Cashless (exercise and sell): sell it all