What Is a Pro Rata Rights?
Pro rata rights let an investor buy enough shares in a future round to keep their ownership percentage from shrinking.
How it works
When a company sells new shares, existing owners are diluted: their percentage falls. A pro rata right gives an investor the option, but not the obligation, to buy a portion of the new round equal to their current ownership. If they own 5 percent and use the right, they may buy 5 percent of the new shares and stay at roughly 5 percent.
These rights are often granted in a side letter or in the investment agreement, and they may be limited to larger investors. Many SAFEs do not include them by default, though side letters can add them. Terms vary, so read the exact wording.
Example
Suppose an investor owns 4 percent after a seed round. The company later raises $5 million in a Series A. With pro rata rights, the investor can invest 4 percent of the $5 million, which is $200,000, and keep the same percentage of the company (before other effects such as an option pool increase). Without the right, they can invest only if the company allows it, and their stake shrinks.
Why founders care
Pro rata rights are valuable to investors and can be a constraint for founders. A new lead investor often wants a large share of the next round, and existing pro rata rights can crowd them out. Founders should keep track of who holds them and how much room they take. Giving them widely in early rounds can complicate later ones.
Common mistakes
- Granting pro rata rights to many small investors without tracking them.
- Forgetting that exercising them needs the investor's money at closing.
- Not accounting for them when planning the size of the next round.
- Confusing pro rata rights with a right to a board seat or information.
Frequently asked questions
What are pro rata rights?
They are an investor's option to buy a share of a future funding round proportional to their current ownership, so that new share issuances do not reduce their percentage.
Do pro rata rights prevent dilution?
Only partly. They let an investor buy more shares to hold their percentage, but the investor must pay to do so. Other changes, such as a larger option pool, can still affect their stake.
Related terms
Go deeper
- SAFE vs Convertible Note: Which Is Better for Founders? GuideSAFE vs convertible note explained: how each works, valuation caps, discounts, interest and maturity, with a worked example and the trade-offs for founders.
- Startup Funding Stages: Pre-Seed to Series C Explained GuideStartup funding stages explained in plain English: pre-seed, seed and Series A, B and C, what each round is for, what investors expect and how rounds are sized.
All 70 startup terms · More terms starting with P · Guides
General information, not legal, tax or financial advice. Reviewed 11 November 2026.