Cap tables and dilution: the arithmetic of ownership

A capitalization table (cap table) is the record of who owns what fraction of a company's equity. The basic structure is a list of holders with the number of shares (or share-equivalents) each one holds, plus the total shares outstanding.

A simple example at the founding of a company:

The number of shares (10 million here) is arbitrary; what matters is the proportion. Companies typically issue 10 million shares at founding by convention; a 30% stake is 3 million shares whether the total is 1 million or 10 million.

Real-world cap tables get more complex than this because companies issue multiple share classes, options, warrants, and convertible securities. The rest of this lesson lays out the structure used to manage that complexity.

Most startups have at least two share classes by their first priced round.

Common stock. The default share class. Held by founders, employees (via option exercise or grants), and consultants. Common shareholders have voting rights and receive whatever is left in a liquidation after preferred shareholders are paid.

Preferred stock. Issued to investors in priced funding rounds. Carries specific rights spelled out in the company's certificate of incorporation: a liquidation preference that pays out before common in a sale or wind-down, anti-dilution protection that adjusts ownership if a later round is priced lower, board representation rights, protective provisions that require investor approval for major company actions, and others.

Within preferred, classes are typically labeled by round: Series Seed Preferred, Series A Preferred, Series B Preferred, and so on. Each series has its own preference terms and may be senior or pari passu to other series in liquidation.

Later-stage companies may have:

• Junior preferred (rare; subordinated to other preferred).
• Founder-friendly classes with extra voting power (super-voting common, used in some founder-led public companies).
• Special classes for specific transactions (e.g., crossover-round preferred with unique terms).

A cap table records the number of shares in each class. Total ownership is computed per share, but the rights attached to those shares differ by class. The next lessons (term sheets, exit waterfalls) examine what those rights mean economically.

Beyond actual shares, cap tables track options and warrants — instruments that grant the right (not obligation) to acquire shares in the future at a fixed price (the strike price or exercise price).

Stock options are typically granted to employees as incentive compensation. The option becomes exercisable as the employee vests over a typical 4-year schedule with a 1-year cliff. Once exercised, the employee pays the strike price and receives common shares.

Warrants are similar but typically issued to investors, lenders, or partners — usually with longer expiration periods and different terms (some sold for cash, some issued as a sweetener to a debt or service agreement).

For cap-table purposes, options and warrants are tracked because they represent potential dilution. If they vest and are exercised, they will become shares, reducing every existing shareholder's percentage. The standard convention is to report ownership on a fully diluted basis that assumes all options and warrants are exercised and all convertible securities are converted.

The distinction:

• Issued shares. Actually outstanding common and preferred stock.
• Fully diluted shares. Issued shares + outstanding options + outstanding warrants + shares underlying convertible securities (SAFEs, notes) + shares in the unallocated option pool.

A founder who 'owns 50%' may own 50% of issued shares but only 35% on a fully diluted basis if there are large option pools, outstanding warrants, and convertible securities outstanding. Press headlines often quote the issued basis; investor discussions almost always quote the fully diluted basis.

An option pool is a reserve of authorized but unissued shares set aside to grant as options to current and future employees.

At company formation, founders typically authorize ~10–20% of fully-diluted shares for the pool. As employees are hired and option grants are issued, the pool is drawn down. When the pool runs low, the company authorizes additional shares — usually at the next priced funding round.

Pool expansion at funding rounds. Investors expect a pool large enough to hire over the next 18–24 months (commonly 10–20% of post-money fully diluted) before they wire money. Founders agree to expand the pool to that size before the round closes. Because the new shares are authorized before the investors purchase, the dilution comes from the existing shareholders (founders and earlier investors), not from the new investors.

Numerically: if a Series A investor invests $5M for 20$25M post-money valuation, and the company also expands the option pool from 10% to 15% pre-investment, the pool expansion dilutes existing shareholders by ~5 percentage points more than the investor's purchase alone.

This 'option-pool shuffle' is one of the most consequential negotiation points in a Series A term sheet. The math is straightforward but easy to miss in the headline ('5M at 20% post' sounds simple; the actual founder dilution depends on the pool expansion). Founders who model the cap table carefully before the round are in a much better position to negotiate.

Dilution is the reduction in an existing shareholder's percentage ownership when new shares are issued.

Before an issuance, existing holders own all of the company. After issuance, they own a smaller fraction because the denominator (total shares) grew.

Numerical example: a holder owns 1,000,000 shares of a company with 10,000,000 total shares — a 10% stake. The company issues 2,500,000 new shares to investors. After the issuance:

• Total shares: 12,500,000.
• Holder's shares: still 1,000,000 (unchanged).
• Holder's percentage: $1,000,000 / 12,500,000 = 8\%$.

The holder lost 2 percentage points to dilution. The new investors received 20% ($2,500,000 / 12,500,000$).

The dilution formula. If existing holders collectively own $1 - x$ of the post-issuance company and the new investors own $x$, then the multiplicative dilution factor for each existing holder is $1 - x$. An existing 10% holder becomes a 10% × (1 - x) = 10% × (1 - 0.20) = 8% holder.

Across multiple rounds, dilution compounds multiplicatively. A founder with 40% pre-Seed becomes:

• 40% × (1 - 0.20) = 32% after Seed (20% dilution).
• 32% × (1 - 0.20) = 25.6% after Series A.
• 25.6% × (1 - 0.20) = 20.5% after Series B.
• 20.5% × (1 - 0.20) = 16.4% after Series C.

After four rounds at 20% dilution each, the founder's stake has gone from 40% to ~16%. The multiplicative compounding is structurally important: a founder who fundraises five times before exit may hold 10–20% of the company at exit even without 'losing control' on any particular round.

This is why ownership-per-dollar-raised matters more than headline ownership. A founder who raises $50M to grow the company to$500M valuation may own less of a bigger company than one who raises $5M to reach$50M valuation — but the absolute dollar amount of equity can be very different.

Pro-rata rights give existing investors the right (not obligation) to participate in future funding rounds at the level needed to maintain their ownership percentage.

Mechanics: if an investor owns 20% of the company pre-round, and the round is raising $10M, they can invest up to$2M of that $10M to keep their 20$8M dilutes everyone proportionally (including this investor's other holdings).

Why investors want pro-rata:

• Maintain ownership in winners. A small investor in a successful seed round can keep a meaningful position by exercising pro-rata in subsequent rounds.
• Signal-value. Existing investors continuing to invest is taken as a positive signal by new investors at later rounds.
• Capital-efficient diversification. Investing more in companies that are working out is a structural feature of how venture portfolios produce returns.

Why founders or new investors might resist:

• Allocation constraints. A hot round may be oversubscribed; pro-rata claims from earlier investors crowd out new investors that the founders want on the cap table.
• Round economics. Pro-rata participation by all earlier holders can mean no allocation for new leads, complicating fundraising.
• Founder dilution math. Pro-rata participation does not change total dilution at this round, but it changes which holders are diluted by what.

Later-round investors (Series B and later) often require pro-rata rights as a standard term. Earlier-round investors (seed and Series A) increasingly do too. Some founders negotiate caps or waivers in specific situations. The next lesson examines how these and other terms are written into the priced-round documentation.

Vesting is the schedule by which equity becomes the holder's to keep. The standard structure for employee options and founder equity:

• 4-year vesting with a 1-year cliff.
• Cliff: nothing vests for the first year. At month 12, 25% vests in a lump.
• After the cliff: monthly (or quarterly) vesting for the remaining 36 (or 12) periods until fully vested at month 48.

Why vesting exists:

• Retention. An employee who would lose unvested equity has a financial incentive to stay through the vesting schedule.
• Reversion of unvested equity. If an employee leaves before fully vesting, the unvested portion is forfeited and (typically) returned to the option pool.
• Founders too. Founders typically vest their own equity on the same 4-year schedule. This protects co-founders from each other: if a founder leaves at month 6, the company keeps the unvested 87.5%.

Acceleration clauses modify the schedule under specific conditions:

• Single-trigger acceleration. Some or all unvested equity vests on a change of control (acquisition). Less common today.
• Double-trigger acceleration. Vesting accelerates on a change of control and a subsequent involuntary termination. More common; protects employees but does not transfer the entire economic incentive at the time of acquisition.

Founder vesting and acceleration terms are negotiated at the first priced round (and reset by many investors at that time, even if founders had already 'vested' under their own founder agreement). The structural lesson: vesting aligns long-term incentives, and the specific schedule and acceleration triggers can be the difference between a founder departing with substantial equity vs. forfeiting most of it.

Three structural points for the cursus.

• Ownership has multiple denominators. Issued vs fully diluted vs voting. Each one captures something different. Press releases and pitch decks tend to use the most flattering denominator. Investors and operating analysts use the fully diluted denominator.
• Dilution compounds multiplicatively. Each fundraising round multiplies the existing holder's stake by $(1 - x_i)$, where $x_i$ is the investor share at that round. Over multiple rounds, what looks like modest per-round dilution accumulates substantially.
• The cap table is a living document. Option grants, exercises, transfers, repurchases, vesting, and funding rounds all change it. Founders and CFOs who can model the cap table in advance of decisions make better decisions; those who treat it as administrative paperwork are routinely surprised.

The next lesson moves from the cap-table mechanics into the math of a priced round: pre-money vs post-money valuation, how new shares are issued at what price, and how the math of a round actually closes.