The price something would sell for in a normal market between willing parties. Used to value services, assets, or shares. For private companies, typically established through a 409A valuation.
fair market value
/fɛr ˈmɑːrkɪt ˈvæljuː/ noun — The hypothetical price at which an asset would change hands between a willing buyer and a willing seller, both possessing reasonable knowledge of the relevant facts and neither under duress. Abbreviated FMV. In startup equity, the term most commonly appears in the context of 409A valuations and option strike prices.
Why it matters
Fair market value is the foundation for pricing stock options, calculating tax obligations, and valuing contributions in a dynamic equity model. Getting it wrong creates legal and tax problems. The IRS uses FMV to determine whether options were priced correctly and what taxes are owed.
If a company issues stock options below fair market value — even by accident — the recipients face immediate ordinary income tax on the discount plus a 20% penalty under Section 409A of the Internal Revenue Code. This is why establishing a defensible FMV through a formal appraisal is not optional for any company granting equity to employees or contractors.
Beyond options, FMV matters in dynamic equity models where time contributions are converted to dollar values using market rates. The market rate is each contributor's FMV of labor — what a reasonable employer would pay for equivalent work. Setting accurate market rates ensures that ownership accumulates in proportion to genuine economic contribution.
How it works
For private companies, FMV is typically established through a 409A valuation performed by an independent appraiser. The appraiser considers comparable company transactions, the company's financial performance, and market conditions. The three main valuation methodologies are the market approach (comparable transactions or public company multiples), the income approach (discounted future cash flows), and the asset approach (net asset value).
For very early-stage companies with no revenue, the FMV of common stock is often a fraction of the preferred stock price — typically 20% to 33% — due to the lack of liquidation preferences and other rights that preferred shareholders hold. For example, if preferred stock is priced at $1.00/share in a seed round, common stock might be valued at $0.20 to $0.30/share.
A 409A valuation is valid for 12 months or until a material event — such as a new funding round — occurs. Startups typically refresh their valuation annually and immediately after each raise. The appraiser's report provides a safe harbor against IRS challenge as long as the company relied on it in good faith.
| Method | How it works | Best for |
|---|---|---|
| Market approach | Compares to similar transactions or public multiples | Post-revenue startups with comparable comps |
| Income approach | Discounts projected future cash flows to present value | Mature companies with predictable revenue |
| Asset approach | Values net assets (assets minus liabilities) | Early-stage pre-revenue companies |
| Recent funding round | Uses the price per share from the most recent round | Companies that recently closed a priced round |
History and origin
The concept of fair market value has roots in common law going back centuries, but its modern legal definition was formalized by the U.S. Treasury in the mid-20th century for estate and gift tax purposes. The IRS Revenue Ruling 59-60 (1959) established the canonical definition still used today: the hypothetical price at which property would change hands between a hypothetical willing buyer and a hypothetical willing seller, each having reasonable knowledge of the relevant facts.
The specific application to startup stock options accelerated after the dot-com boom. Many companies in the late 1990s and early 2000s issued options at prices they informally declared to be FMV without independent appraisals. The IRS cracked down, and Congress responded by enacting Section 409A of the Internal Revenue Code in 2004 as part of the American Jobs Creation Act. Section 409A imposed strict rules on deferred compensation — including stock options — and created significant penalties for options granted below FMV.
The 409A safe harbor valuation industry grew directly from this legislation. What was once an informal estimate became a formal, recurring compliance requirement for virtually every venture-backed startup. Today, independent 409A appraisals are standard practice, performed by firms like Carta, Preferred Return, and Andersen, and refreshed regularly throughout a startup's lifecycle.
Frequently asked questions
What is fair market value in a startup context?
Fair market value (FMV) is the price an asset — including company shares — would sell for between a willing buyer and a willing seller, both with reasonable knowledge of the facts and neither under compulsion to transact. For startups, FMV most commonly comes up when pricing stock options and when valuing sweat equity contributions.
How is fair market value determined for a private company?
For private companies, FMV is typically established through a 409A valuation conducted by an independent third-party appraiser. The appraiser uses methods like the market approach (comparable transactions), the income approach (discounted cash flows), and the asset approach. For early-stage companies, the market approach using recent funding rounds is most common.
Why is fair market value important for stock options?
The IRS requires that incentive stock options (ISOs) and non-qualified stock options (NSOs) be granted at or above fair market value. If options are issued below FMV — called a "discount option" — the recipient faces immediate ordinary income tax on the spread plus a 20% penalty under Section 409A. A proper 409A valuation protects both the company and the employee.
How often should a startup update its 409A valuation?
A 409A valuation is valid for 12 months or until a material event occurs — whichever comes first. Material events include closing a new funding round, a significant change in the company's business or financial condition, or preparing for an exit. Most startups refresh their 409A annually or immediately after each funding round.
What is the difference between FMV and the preferred stock price?
Preferred stock (sold to investors) carries special rights like liquidation preferences and anti-dilution protection that make it more valuable than common stock. The FMV of common stock is therefore typically a fraction of the preferred price — often 20% to 33% at early stages. This discount is why founders and employees can receive options at a lower price than what investors pay.
Does fair market value apply to sweat equity and dynamic equity models?
Yes. In dynamic equity models, contributions are valued using each contributor's market rate — the FMV of their time. Setting accurate market rates ensures that equity accumulates proportionally to actual economic contribution. If rates are inflated or deflated, the ownership split becomes unfair from the start.
Can founders set their own fair market value?
For option pricing purposes, founders cannot simply declare their own FMV — an independent 409A appraisal is required for the valuation to qualify as a safe harbor under IRS rules. However, for internal purposes like dynamic equity contribution tracking, co-founders can agree on market rates for their time as long as the rates are documented and reflect what a reasonable employer would pay.
Learn more
- Pre-money valuation: how startups set their price
- ISOs for startup employees: the complete guide
- What is a cap table and why does it matter?
- The 83(b) election explained: why timing matters for founders
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