CEO equity starts at the founding split (often 30 to 70% depending on team size) and dilutes through successive rounds. By Series C, founder CEOs typically own 10 to 25% of the company. By IPO, 5 to 15% is common. Maintaining a meaningful CEO stake matters both for incentive and for the optics of long-term commitment.
When a founder CEO is replaced by an external CEO, the equity terms (size of grant, vesting, severance, acceleration) become a strategic question handled by the board's compensation committee.