Startup Dilution: Pre-Money, Post-Money and Pools
Every round sells part of the company. Dilution isn’t bad when the company grows faster than ownership shrinks. What founders need is to understand how each term moves the numbers, especially the option pool and the difference between pre-money and post-money.
How does a funding round dilute founders?
New shares are issued to investors, so every existing holder owns a smaller percentage. Investor ownership equals the amount raised divided by the post-money valuation, and the post-money valuation is the pre-money valuation plus the money raised. Raising $2 million at an $8 million pre-money gives a $10 million post-money, so the investor owns 20%. SAFEs add their own dilution when they convert; see how SAFEs convert.
What is the option pool shuffle?
Investors often require the option pool to be increased before the round, inside the pre-money valuation. That means the new pool shares dilute existing holders only, not the new investor. The effective pre-money valuation for founders is lower than the headline number.
| Holder | Shares | Ownership |
|---|---|---|
| Founders | 9,000,000 | 70.0% |
| Option pool (500,000 existing + 785,714 new) | 1,285,714 | 10.0% |
| Seed investor | 2,571,429 | 20.0% |
| Total | 12,857,143 | 100% |
Which investor terms affect future dilution?
| Term | What it does |
|---|---|
| Pro rata rights | Let investors buy into later rounds to keep their percentage |
| Anti-dilution | Adjusts investors’ conversion price if a later round is priced lower; broad-based weighted average is the common, milder form |
| Liquidation preference | Investors get their money back first on a sale; 1x non-participating is common |
| Pool top-ups | Increase the pool, usually from the pre-money |
Negotiate the pool size against a real hiring plan; see employee equity grants.
How much do founders typically own over time?
Each round commonly sells something like 10% to 25% of the company, plus pool top-ups. Founders who start with 100% often hold well under half after a Series A and B. The goal isn’t to avoid dilution, but to raise enough to reach milestones that increase the company’s value faster than ownership falls.
Founding, after SAFEs, after seed, after Series A, after Series B. Illustrative.
Own less of something worth more.
Dilution is the price of growth. Judge each round by what it lets the company become, not by the percentage alone.
What should founders do before each round?
- Model the round at two or three valuations and raise sizes.
- Agree the pool size from a hiring plan, not a round number.
- Check pro rata, anti-dilution and preference terms with a lawyer.
- Include all SAFEs and notes in the model.
- Update the cap table immediately after closing.
Start from the cap table, and see the investor side in how to raise a seed round. Canadian founders should also check CCPC status before large rounds: CCPC status and SR&ED.
Frequently asked questions
What is the difference between pre-money and post-money valuation?
Pre-money is the company’s value before new money; post-money is pre-money plus the amount raised.
How do I calculate investor ownership?
Divide the amount raised by the post-money valuation. $2 million at a $10 million post-money is 20%.
What is the option pool shuffle?
Increasing the option pool inside the pre-money valuation, so the new pool dilutes existing holders but not the new investor.
What are pro rata rights?
The right for investors to buy into future rounds to maintain their ownership percentage.
What is broad-based weighted average anti-dilution?
A common, moderate adjustment to investors’ conversion price if a later round is priced lower.
How much should a startup sell in a round?
Often 10% to 25%, depending on stage and how much is needed to reach the next milestone.