xAI is unusual: a company barely two years old that's already on its third major financing round. The December 2024 Series C valued the company at $50B, with $6B raised in that single round.
The 14× re-rating
xAI's first round in November 2023 priced the company at $3.5B. The Series B in May 2024 brought it to $24B. The Series C in December 2024 to $50B. For an employee who joined at the Series A and stayed through the Series C, their grants have effectively appreciated 14× in 14 months — though the math gets messier once you account for dilution.
Strike prices by cohort
- 2023 cohort (Series A): strikes $4–$8. Implied current value: $83/share. Spread: $75+ per share.
- 2024 H1 cohort (Series B): strikes $35–$60. Spread today: $20–$50 per share.
- 2024 H2 cohort (Series C): strikes likely $75+. Smaller spread; most upside ahead.
AMT risk at xAI scale
Early hires face a real Alternative Minimum Tax problem. Exercising 5,000 ISOs at $6 strike when fair value is $83 generates a $385K spread — fully an AMT preference item. Even at moderate income levels, that triggers a large AMT bill, payable in the year of exercise even if no shares are sold.
Concrete: a 2023 hire with 10,000 ISOs at $6 strike, exercising all today: $770K AMT preference. Estimated AMT owed: roughly $200K. Most early xAI employees should consult a tax advisor before exercising en masse.