Skip to content
StartupCFO logoStartupCFO.AI

Fundraising

Anti-dilution Protection

Quick definition

Mechanism that protects investors from down-round dilution by adjusting their conversion price.

Broad-based weighted average is the founder-friendly standard: it recalculates the conversion price using a weighted formula that accounts for both the new shares and existing fully diluted shares, giving a moderate dilution adjustment. Narrow-based weighted average is harsher (uses only outstanding common). Full ratchet is the most punitive: it resets the prior investor's conversion price to the new (lower) round price entirely, severely diluting founders. Push for broad-based weighted average.

Frequently asked questions

What is Anti-dilution Protection?
Broad-based weighted average is the founder-friendly standard: it recalculates the conversion price using a weighted formula that accounts for both the new shares and existing fully diluted shares, giving a moderate dilution adjustment. Narrow-based weighted average is harsher (uses only outstanding common). Full ratchet is the most punitive: it resets the prior investor's conversion price to the new (lower) round price entirely, severely diluting founders. Push for broad-based weighted average.
Why is Anti-dilution Protection important for startups?
Anti-dilution Protection is a fundraising concept that matters for startup founders because it shows up in fundraising readiness, financial decision-making, and operational discipline at the stage where mistakes are expensive to undo. Founders who understand it are better prepared for diligence, board meetings, and investor conversations.
What category does Anti-dilution Protection belong to?
Anti-dilution Protection is a Fundraising term in the StartupCFO finance glossary, alongside other fundraising concepts that founders, CFOs, and accountants use in startup operations and reporting.
Where can I learn more about Anti-dilution Protection?
Beyond this definition, see the related fundraising terms below, or explore StartupCFO's insights and tools that put Anti-dilution Protection in context. For specific situations, talk to a fractional CFO who can walk through your numbers.

Getting ready to raise?

See the reporting investors expect before diligence starts, and what a clean data room looks like when you walk in.

Want the full sample as a PDF?

No spam, ever. If the download doesn't start, email us.

Or talk it through: