The option pool shuffle: how pre-money top-ups quietly shift dilution onto founders
A closer look at the negotiation mechanic behind option pools, where the top-up is priced in a term sheet, and why that timing decision matters far more than the headline percentage.
Why this is different from the basic option pool question
Most explanations of option pools stop at the headline point: investors ask for a pool of unissued shares, typically set aside for future hires, and that pool has to come from somewhere in the ownership table. What gets skipped is the mechanic that determines who actually pays for it. This is often called the option pool shuffle, and it is one of the more consequential negotiation points in a UK priced round, precisely because it looks like a technicality.
The core mechanic: pre-money or post-money
When a venture investor sets a valuation, they usually specify it as a pre-money figure, the value of the company before new cash comes in. The question is whether the option pool top-up is created before that pre-money valuation is calculated, or after.
If the pool is added before the pre-money valuation is set, existing shareholders, meaning founders and any existing employees or angels, absorb the full dilution from the new pool. The investor’s own percentage stake is protected, because the pool is effectively carved out of the pre-money slice, not the post-money slice they are buying into.
If the pool is instead created after the round closes, or split proportionally between old and new shareholders, the dilution is shared more fairly across everyone, including the incoming investor.
The difference sounds abstract until you run the numbers. A meaningful pool created entirely pre-money, sized to cover a couple of years of hiring, can shift several percentage points of ownership from the founding team to nobody in particular, since unallocated pool shares just sit there until granted. Investors’ effective price per share improves because the pool inflates the share count before their money is counted.
Why investors ask for it this way
Investors are not being unreasonable by wanting an option pool to exist. A credible hiring plan for engineers, a first commercial hire or a finance lead needs equity to offer, and a thin pool forces awkward fundraising just to top it up later, diluting everyone again mid-cycle. Investors also want the pool sized generously enough that it lasts through to the next round without needing another dilutive refresh.
Where it becomes a negotiation rather than a formality is the sizing and the timing. A larger pool than the actual hiring plan requires, folded into the pre-money calculation, effectively lowers the price the investor pays without lowering the valuation they quote publicly. The headline valuation in the term sheet and press release can stay the same while the founder’s real ownership after the round is smaller than a naive calculation would suggest.
What founders should actually check
The first thing to establish is the size of the pool relative to a genuine, bottom-up hiring plan for the period until the next likely raise, not a round number an investor proposes out of habit. An unnecessarily large pool sitting unused for years is dilution with no offsetting benefit to the company.
The second is where the top-up sits: pre-money or post-money. Founders can reasonably push for the pool to be calculated on a post-money basis, or for any top-up beyond the pool’s existing unallocated shares to be shared pro rata between old and new investors rather than loaded entirely onto the existing cap table.
The third is to model the actual post-round ownership table under a few scenarios, not just trust the headline pre-money and post-money numbers quoted in the term sheet. A spreadsheet showing founder, employee, existing investor and new investor percentages before and after the pool top-up makes the effect visible in a way that percentages in a term sheet paragraph do not.
It is also worth asking what happens to unallocated pool shares if hiring plans change. Pools that are never fully granted sometimes get rolled into future rounds or clawed back into general shares, and it is reasonable to ask a lawyer how the specific term sheet treats leftover pool shares.
Where this sits in the wider cap table conversation
This is one detail within a much larger set of cap table and dilution mechanics that founders face across funding rounds, alongside things like liquidation preferences, anti-dilution provisions and pro rata rights. None of it makes the option pool itself avoidable or unreasonable. A functioning employee pool is normal and expected in a UK venture round. The point of scrutinising the shuffle is simply to make sure the dilution founders accept is the dilution they think they are accepting, and that it is being shared fairly rather than absorbed entirely by the people building the company.
Because the exact conventions used by investors, and the tax and legal treatment of option pools, can shift, founders should always verify current mechanics with a solicitor experienced in venture deals and check guidance from established industry bodies before signing a term sheet.