If I'm understanding it correctly, the employees won't have a tax bill if they let the options expire, but they are presumably worth millions so they don't want to just throw that money away. If they exercise then they will owe taxes and they will also have no way to sell the shares (currently) to pay the tax bill.
Sure, but options don't expire while you are an employee.
So if Stripe wants to let employees sell stock, they only have to exercise options equal to the number of shares they will sell, then they can use the proceeds to pay the tax.
I still don't understand why there is a tax bill for Stripe.
