Your offer letter gives you a share count. Without a denominator — the total fully-diluted shares outstanding — that number is meaningless. 10,000 shares at OpenAI (1.34B FD) is 0.0007% of the company. 10,000 at a Series B startup (50M FD) is 0.02% — almost 30× more ownership.
What 'fully diluted' means
Fully diluted (FD) share count includes:
- All outstanding common shares
- All outstanding preferred shares (converted to common)
- All vested AND unvested options
- Unallocated option pool (reserved for future hires)
- Convertible notes and SAFEs (assumed converted)
Why companies don't always disclose this
Private companies are not required to share their cap table. Many will tell you total FD shares if you ask. Some will only tell you the current outstanding count (excluding unallocated pool), which paints a more flattering picture of your percentage.
In an offer negotiation, ask: 'What's the total fully-diluted share count, and what's the allocated vs unallocated option pool?' If you only get one number, ask for the breakdown.