Founder Vesting Acceleration: Single vs Double Trigger

What Vesting Acceleration Is

• Acceleration provisions speed up the vesting of unvested founder shares when specific events occur — typically an acquisition (change of control)
• Without acceleration, a founder with 2 years of unvested shares who gets acquired must stay at the acquiring company for 2 more years to keep all their equity
• Acceleration protects founders from losing earned-but-unvested equity in scenarios they don't control
• The two standard types are single trigger (accelerate on acquisition alone) and double trigger (accelerate on acquisition + involuntary termination)