Who bears dilution when the option pool is topped up?

Hold the financial assumptions constant

Start at 1 January 2026 with 1,000,000 common shares, all held by Founder A, and no existing pool. Investor A supplies 1,000 EURk at a pre-money value of 4,000 EURk. Rights are equal, treasury is zero, and FD pricing includes the Full Pool.

The target is 20% available, ungranted pool units divided by closing Fully Diluted units after both steps. All pool units are ungranted in this example, so available pool and total unexercised pool are identical. A 20% target is not 20% of the opening million shares.

Without a pool, this round would leave the founder at 80% and the investor at 20%, as shown in the priced funding-round workflow. We now change only the pool timing.

Before funding: the pool enters the pricing denominator

The pre-money top-up adds 333,333.333… reserved units before the round. The pricing denominator is therefore 1,333,333.333… FD units. Dividing EUR 4m by that denominator gives EUR 3 per new share, so EUR 1m buys 333,333.333… investor shares.

Closing FD is 1,666,666.666…: 1,000,000 founder shares, 333,333.333… investor shares and 333,333.333… pool units. The founder owns 60%, the investor 20% and the unallocated pool 20%. The investor retains the round’s 20% FD position because the extra pool was included before pricing.

The common shares outstanding are only 1,333,333.333… . On Basic, the founder and investor hold 75% and 25%. Those Basic percentages answer a different question from the 60/20/20 Full Pool result.

After funding: the pool dilutes both shareholding groups

The round is first priced on the original 1,000,000 shares. EUR 4m / 1,000,000 gives EUR 4, and the investor receives 250,000 shares. Immediately after the round, the founder owns 80% and the investor 20%.

Next, the pool top-up adds 312,500 units. This is the native solution to pool / (1,250,000 + pool) = 20%. Closing FD becomes 1,562,500. The founder owns 64%, the investor 16%, and the pool 20%. Both shareholding groups are diluted by the later pool addition.

No common shares are issued merely by reserving the pool. Basic shares remain 1,250,000 and Basic ownership remains 80%/20%. Full Pool measures the additional included capacity; it is not evidence of an exercise or a cash payment.

Reproduce the intervention and inspect the order

1. Download the pre-money top-up case and the post-money top-up case. Import them deliberately as separate examples.
2. Open Ownership → Option Pool / ESOP. Confirm Full reserved pool inclusion, Target % of closing FD = 20%, and Available / ungranted as the target numerator.
3. Inspect the linked funding round and the selected funding treatment. The pre-money case positions the top-up before the round; the post-money case positions it after the round.
4. Read the complete closing preview, including all active equity actions. Review before applying. The download retains the opening ledger and pending actions so that their effect is visible.

Do not hide the denominator or the limits

Counts with repeating decimals are retained by the current engine; tables round them to three decimals. Percentages use the unrounded values. An actual issuance may require agreed rounding terms, which are not invented by this model.

A target top-up requires Full Pool and a compatible linked round. In this setup, an impossible 90% pre-money target blocks the closing result rather than producing a plausible-looking table. Changing timing, pricing basis or grants requires a fresh review.

This is a pool-capacity and ownership calculation. It does not value options, calculate IFRS 2/ASC 718 expense, model VSOP cash settlement, or supply tax or legal advice. For denominator interpretation use Basic vs Fully Diluted. For setup details use pool top-ups and pool timing in funding rounds.