Dilution
Equity dilution is the reduction in an existing holder's percentage ownership when total shares or ownership interests increase and the holder does not acquire enough of the new issuance to maintain the same percentage.
Dilution changes percentage ownership. It does not by itself show whether the economic value of the remaining ownership increased or decreased.
Dilution occurs when the ownership denominator grows. A holder can own the same number of shares after a financing and still own a smaller percentage because the company has more shares outstanding.
New issuance changes the ownership denominator
Follow one existing holder through a simplified financing before considering option pools, convertibles, or other instruments.
- 01Cap table before
Existing holder shares divided by existing total shares
- 02New issuance
Additional shares or ownership interests enter the denominator
- 03Cap table after
The same holder shares represent a smaller percentage unless the holder participates
The value of that percentage depends on company value, rights, terms, and future outcomes.
What is Dilution?
Equity dilution describes a decrease in an existing holder's percentage ownership after the total number of shares or ownership interests increases. The holder may keep the same number of shares, but those shares represent a smaller portion of the expanded total.
New financing is a common source of dilution, but it is not the only one. Employee option pools, exercised options, warrants, restricted equity, SAFEs, convertible instruments, acquisitions paid in shares, and other issuances can change the fully diluted ownership picture. The relevant calculation depends on the security, conversion mechanics, capitalization definition, and transaction documents.
Dilution is not automatically good or bad. A smaller percentage of a more valuable company may be worth more than a larger percentage of a less valuable company. Economic outcomes also depend on price, preference rights, participation, vesting, liquidation terms, and future financing. Percentage ownership is one part of the analysis.
Dilution versus valuation
Valuation describes an agreed or implied company value for a transaction. Dilution describes how the ownership percentages change when new ownership is issued.
A higher pre-money valuation can reduce the percentage issued for the same amount of new money in a simple priced round, but the final ownership result can also be affected by option-pool changes, converting securities, transaction costs, and negotiated terms.
Dilution versus ownership value
Ownership percentage and ownership value are not the same measure. A holder can be diluted while the paper value of the remaining stake increases if the company value rises enough. The reverse is also possible.
Paper value is not guaranteed liquidity. Transfer restrictions, preferences, taxes, vesting, future rounds, and the actual outcome of the business all matter.
Pre-money and post-money context
Pre-money valuation
The negotiated company value immediately before the new investment in a simplified priced round.
Post-money valuation
In the simple case, pre-money valuation plus the new primary investment.
Cap table mechanics
The share price, new shares, option-pool treatment, and converting instruments determine the actual ownership percentages.
Why it matters
Dilution affects governance, voting, proceeds, employee incentives, and the share of future value attributable to each holder. Founders and employees need to understand both the percentage change and the transaction terms that create it.
The question is not simply how to minimize dilution. A financing can provide capital that changes the company's options and value. The relevant decision weighs the capital, operating plan, timing, ownership effects, rights, and risks together.
Simplified share formulas
- Holder shares before and after the transaction
- Total outstanding shares on the relevant basis
- New shares issued in the financing
- Option-pool changes and any convertible securities or warrants
- The capitalization definition used in the transaction documents
Simplified share formulas
Ownership % = Holder shares / Total shares outstanding × 100 New ownership % = New investor shares / Post-issuance total shares × 100
Illustrative share-count example
A founder owns 600,000 of 1,000,000 outstanding shares, or 60%. The company issues 250,000 new shares to an investor. If nothing else changes, the post-issuance total is 1,250,000 shares and the founder still owns 600,000.
The founder's post-issuance ownership is 48%. The percentage fell because the denominator grew. This simplified example excludes option-pool changes, SAFEs, convertibles, warrants, preferences, taxes, and other terms that can materially change a real financing.
How RunwayCal helps
RunwayCal does not maintain the legal cap table or calculate transaction dilution. It can help a team review cash, runway, planned spending, and financing timing before a fundraising decision.
Use a qualified legal, tax, and equity-administration process for the cap table, security terms, and holder-specific consequences.
Common mistakes
- 1Using investment divided by post-money valuation as a universal dilution formula.
- 2Ignoring option-pool changes, SAFEs, convertibles, warrants, or other securities.
- 3Treating percentage ownership as the same thing as economic value or cash proceeds.
- 4Relying on a planning explanation instead of the legal capitalization records and transaction documents.
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