Glossary · Shareholder rights & company governance
Pro Rata Rights
Also called: participation rights · preemptive rights
Pro rata rights are an existing investor's entitlement to buy enough of a company's newly issued shares in later financings to keep its percentage ownership, usually measured on a fully diluted basis.
If an investor owns 8% of a company and the company sells new shares, the investor's stake shrinks unless it buys some of them. A pro rata right guarantees the chance to buy its share of the new issue, here 8%, on the same terms as the new investors. It is a right, not an obligation, and it costs money to use.
Formula
Pro rata allocation
- oFD
- the holder's ownership before the round, usually shares held (as converted) divided by fully diluted shares
- R
- total amount raised in the new round
- N
- new shares issued in the round
Documents differ on the denominator (fully diluted including or excluding the unallocated pool, or only shares held by major investors) and on whether the right covers the whole round or only the portion not reserved for a new lead.
Where the right comes from
In US venture financings the right is contractual. The National Venture Capital Association (NVCA) model Investors' Rights Agreement grants it as a "right of first offer" on new securities to "Major Investors", investors holding at least a negotiated number of shares, with carve-outs for the same issues excluded from anti-dilution protection (equity plan grants, conversion shares and similar). Unexercised allocations may be offered to the investors who did exercise. The right usually ends at an IPO or a sale. Holders of SAFEs generally have no pro rata right unless they sign a side letter; In 2018 Y Combinator dropped the default pro rata right from its SAFE, which had applied to the round after conversion, and replaced it with an optional side letter covering the round in which the SAFE converts.
Statutory pre-emption (UK) and the Delaware default
Some jurisdictions give shareholders a statutory right instead of, or as well as, a contractual one. In the UK, section 561 of the Companies Act 2006 (as in force on 2 October 2026) requires a company to offer new equity securities first to existing holders of ordinary shares, in proportion to the nominal value of their ordinary shareholdings and on the same or more favourable terms. The right does not apply to an allotment paid up wholly or partly otherwise than in cash (section 565). A private company can exclude it in its articles (section 567), and directors with a general allotment authority can be given power, by the articles or by special resolution, to allot as if it did not apply or applied with modifications (section 570). Private companies commonly use these routes and replace the statutory right with negotiated terms. Under Delaware law, by contrast, no stockholder has a pre-emptive right unless the certificate of incorporation expressly grants it (Delaware General Corporation Law section 102(b)(3)), which is why US venture pro rata rights usually sit in investor agreements.
Variants
Super pro rata rights allow an investor to buy more than its current percentage, often negotiated by early investors in exchange for early risk. Major-investor thresholds restrict the right to larger holders. Leads in competitive later rounds often ask existing investors to waive or reduce pro rata so the lead can reach its target ownership; most agreements let a stated majority of major investors waive the right for all.
Rights versus participation
Having the right does not mean using it. Exercising pro rata needs capital, which is why venture funds hold follow-on reserves, and a decision rule, because following on into every company spreads reserves across companies that do not justify them. LPs therefore look at how often a manager exercised pro rata in the companies that became its best outcomes, and at what ownership it held in them at exit, rather than at the existence of the right.
Worked examples
Illustrative $20m round at $80m pre-money
A company with 10,000,000 fully diluted shares raises $20m at an $80m pre-money valuation. The price is $80m / 10,000,000 = $8.00; it issues 2,500,000 new shares; post-money is $100m.
Using or not using the right
An existing investor holds 800,000 shares (8%). If it does not participate, its stake falls to 800,000 / 12,500,000 = 6.4%. Its pro rata amount is 8% × $20m = $1.6m, which buys 200,000 shares at $8.00 and keeps it at 1,000,000 / 12,500,000 = 8.0%.
Examples are illustrative; figures are not market data.
Not the same as
- Anti-Dilution Protection: Anti-dilution protection adjusts a conversion price when shares are sold below it; it does not let the holder buy new shares.
- Right of First Refusal: A right of first refusal applies when an existing holder sells shares to a third party; pro rata rights apply when the company issues new shares.
- Follow-On Reserves: Reserves are the fund's capital set aside to use pro rata and other follow-on rights; the right is the contractual entitlement.
Common mistakes
- Calculating the pro rata share on issued shares rather than the fully diluted basis the agreement specifies.
- Assuming pro rata protects against dilution from an option pool increase made before the round; that increase is often outside the right.
- Treating the right as an allocation guarantee in competitive rounds, where it is frequently waived or cut back by majority vote.
- Confusing the NVCA "right of first offer" on new securities with a right of first refusal on transfers.
Questions
How do you calculate a pro rata share?
Multiply the holder's fully diluted ownership before the round by the round size. An investor owning 8% of a company raising $20 million has a pro rata amount of $1.6 million.
Do SAFE holders have pro rata rights?
Only if granted separately, usually in a side letter. The standard Y Combinator post-money SAFE does not contain one.
Sources
- NVCA Model Legal Documents. National Venture Capital Association, NVCA, Certificate of Incorporation, Stock Purchase Agreement, Investors' Rights Agreement updated October 2025; Voting Agreement June 2026; ROFR and Co-Sale April 2026; Management Rights Letter and Indemnification Agreement July 2020. Status: Current (checked 2026-10-01). Investors' Rights Agreement, right of first offer (Major Investors, carve-outs, over-allotment, termination, waiver) — supports: Contractual pro rata right in US venture financings
- Y Combinator SAFE (post-money) documents and SAFE User Guide. Y Combinator, Post-money SAFE introduced 2018. Status: Current (checked 2026-10-01). Pro rata side letter; Post-Money SAFE User Guide, introduction (p. 3) and Appendix III — supports: SAFE pro rata rights granted by optional side letter since the 2018 post-money SAFE
- Companies Act 2006, Part 17 Chapter 3: pre-emption rights (ss.560, 561, 565, 567, 570). UK Parliament (legislation.gov.uk), Revised text; s.561 page states it is up to date with changes known to be in force on or before 30 September 2026. Status: in force (checked 2026-10-01). Secs. 560(1), 561(1), 565, 567(1)-(2), 570(1) (revised text up to date to 2 October 2026) — supports: UK statutory pre-emption and its exclusion or disapplication
- 8 Del. C. s.102 - Contents of certificate of incorporation (Delaware General Corporation Law). State of Delaware (Delaware Code Online), Delaware Code Online, Title 8 ch. 1 (accessed 2026-10-01). Status: in force (checked 2026-10-01). 8 Del. C. Sec. 102(b)(3) — supports: No pre-emptive right unless expressly granted in the certificate of incorporation