VC & PE Glossary
What Is Dilution?
Updated
Definition
Dilution is the reduction in an owner's percentage stake when a company issues new shares — typically during fundraising, option pool increases, or convertible instrument conversion.
Useful for: Founders, Operators, Investors
Dilution happens when a company issues additional equity, decreasing each existing owner’s percentage ownership even if their share count stays the same.
How it works
Primary causes in venture-backed startups:
- Priced rounds — new preferred shares to investors
- Option pool expansion — reserved shares for hires, often part of pre-money negotiation
- Convertible notes and SAFEs converting in a round
- Warrant exercise and secondary sales (secondary does not dilute others if no new shares)
Dilution differs from valuation change. Owning less of a much more valuable company can still increase dollar wealth — founders focus on ownership % and absolute value together.
Fully diluted cap table math includes all converting instruments. Anti-dilution provisions protect preferred investors from down-round repricing — often diluting common further.
Pro rata rights let investors buy new shares to maintain percentage; founders without capital get diluted faster.
Why it matters
- Founders: Run scenarios before term sheets. A high valuation with massive pool refresh can dilute more than a lower valuation with clean terms.
- Operators: Employee grant sizes depend on remaining pool and future dilution expectations — communicate refresh plans honestly.
- Investors: Track effective ownership through reserves and follow-ons. Heavy dilution without traction resets incentives.
Common mistake
Looking only at pre-money valuation while ignoring option pool shuffle and note stacks. Effective dilution exceeds headline round percentage.
Related ideas
See also dilution analysis, cap table, pro rata rights, and anti-dilution.
Related terms
- Cap Table — A cap table (capitalization table) is the record of who owns equity in a company — shares, options, warrants, and convertible instruments — and how ownership percentages change after each financing.
- Dilution Analysis — Dilution analysis models how ownership percentages change across financing events — new rounds, pool expansions, note conversions, and exit scenarios — on a fully diluted basis.
Common questions
Short answers for founders, LPs, and operators