Dilution Modeling

The Reality of Dilution

Dilution is the mathematical certainty of raising equity capital. Every time a company issues new shares to an investor, the percentage ownership of all existing shareholders decreases.

The Mathematics of Dilution

Dilution is calculated by comparing a shareholder's ownership percentage before and after a financing event.

Example: A founder owns 100% of a company. They raise a Seed round, selling 20% to investors. The founder now owns 80%.

In a Series A, they sell another 20%. The founder's new ownership is:
80% × (1 - 0.20) = 80% × 0.80 = 64%

Percentage Dilution vs. Value Accretion

Founders often focus intensely on minimizing percentage dilution. However, the goal of venture capital is to grow the total pie significantly faster than the slice is shrinking.

Owning 100% of a $1M company ($1M value) is worse mathematically than owning 20% of a $100M company ($20M value).

Pro-Rata Rights

Early-stage investors are acutely aware of dilution. To protect themselves, they negotiate Pro-Rata Rights. This right allows them to participate in future funding rounds to maintain their current ownership percentage.

If an investor owns 10% of a company, and the company raises a $20M Series B, the investor has the right to invest $2M to ensure they are not diluted by the new shares being issued.

Anti-Dilution Protection (Down Rounds)

What happens if a company raises money at a lower valuation than the previous round (a "Down Round")? Without protection, early investors would be severely punished.

Preferred stock often includes anti-dilution provisions. The most common is the Broad-Based Weighted Average Ratchet. This formula mathematically adjusts the conversion price of the earlier preferred stock downward, granting those investors more common shares to partially offset the pain of the down round. A "Full Ratchet" is much more punitive to founders, resetting the old share price entirely to the new, lower share price.