One should exercise at the earliest possible convenience. If I'd exercised on day 1 when I joined a startup, I wouldn't have owed tax because I wasn't getting a discount, but a locked-in price. So when I exercised after the value increased, I then owed tax.
I've seen it suggested that one should exercise on day 1. But that doesn't have to mean you pay for them immediately (after all, you don't get to keep them immediately - you have to wait for vesting...), so you work out a payment plan with deductions every paycheck so that you've pay fully for whatever is vested at the time it vests.
I've seen it suggested that one should exercise on day 1. But that doesn't have to mean you pay for them immediately (after all, you don't get to keep them immediately - you have to wait for vesting...), so you work out a payment plan with deductions every paycheck so that you've pay fully for whatever is vested at the time it vests.