Depends on when the 409a was performed and when the exercise happened. When the startup I work at got our Series A, a new 409a was done and increased the share price by roughly the same multiple of the new valuation, and now I have a wide spread for AMT should I exercise my options because of the new 409a.

So it's possible for employees to have joined after the new 409a when it was valued at 1.5bln and early exercised against that value.

I have a hard time actually visualizing this math. Let’s say you join a 1.5B valued company and get offered $100k in stock options, but at $20k. So an 80% discount.Assuming the company meets the revenue goals maybe 10 years in the future but otherwise no other growth beyond the valuation, is it worthwhile for the employee to exercise the options, not early? Presumably they would have to turn around and pay another $20k in taxes the year that they exercised

And then they'd have sold at the higher value, because the sale price is almost certainly higher than whatever the 409a price was.