Most startups use double trigger acceleration for vesting. The first trigger was the acquisition and the second was the termination (not offered a position). So they would vest their entire equity grant.
Of course that implies that the equity is worth anything. Most acquihires are at low multiples so the VCs tend to take the entire price, leaving founders and employees with nothing.
Even in low multiples typically the VCs creates a decent incentive for the founders to stay at the acquired company (otherwise the acquihire will fail), but they aren't getting filthy rich.
I would be curious about "most". My n=1 experience didn't have acceleration terms. In fact, all of my remaining unvested ISO's vanished at acquisition ...
Interesting. And I assume that there's a lot of fudge room on the valuation as well with more of it being shifted towards hiring bonuses for those kept on?
Of course that implies that the equity is worth anything. Most acquihires are at low multiples so the VCs tend to take the entire price, leaving founders and employees with nothing.