Pre-Seed vs Series A: Option Pool Sizing Split

You want the truth on option pools from pre-seed to Series B? Here it is.

Pre-seed and seed pools sit around 10-15% of fully diluted shares. Most founders target 12-13% at funding, with 10% as a safe floor. You can push higher if you expect rapid hiring or if your sector requires it. Deep Tech (Sector needing specialized talent (e.g., PhDs, scientists) to justify larger pools) an Biotech push to 15% or more to attract PhDs and scientists, while SaaS and E‑commerce sit around 10-12.5%. A founder I spoke with kept a 15% seed pool and topped it up at Series A to around 10% pre-money; that approach can work if hiring velocity is reliable.

At Series A, the pool is usually adjusted to 10-12%. Investors expect a pre-money pool bump, and that bump dilutes founders, early investors, and others. Series B and beyond shrink to 5-8% as teams mature and hiring slows. Carta’s Q4 2023 data backs this: seed pools median at 12.5%, moving away from the old 10% rule. Angels and funds like AngelList note seeds often sit in the 12-13% neighborhood.

Buffers matter. Pre-seed buffers for unforeseen hires sit at 30-40%, while seed stage uses about 25%. If you set a 20% pool and don’t use it, you discount Series A investors. Dilution math cannot be ignored. For most teams, size the pool to cover 18-24 months of hiring needs without mid-round increases.

What gets equity?

C-suite roles typically claim 1.5-3.0% per hire (CTO, CRO). VP roles 0.8-1.5%. Senior engineers and PMs run 0.4-0.8%. The first 10 non-founding employees range 0.3-1.0% each. This matches market data: pools must support a durable hiring plan, not a one-time grant spree.

A practical rule: size the pool to the 18-24 month hiring plan, not to a “nice to have” number. If you anticipate 8-12 key hires before the next round, map those grants directly to those roles and time-box them against markers. The math matters more than the buzzwords. Pre-seed buffers are higher because early plans shift; seed buffers are lower but still meaningful.

How to size and plan the pool by sector

Different sectors treat pools differently. Deep Tech or Biotech often justify 15%+ to attract specific talent. SaaS and E-commerce tend to stay closer to 10-12.5% because hiring is more expandable and market competition differs. The common move is to top up at Series A to around 10% pre-money, and most investors want that confirmed before the round closes.

On the strategy side, the pool should not be set in stone. If you forecast hiring velocity will exceed expectations, plan a Series A top-up before the round. If you don’t, you will face heavier dilution later. The typical pre-money pool increase at Series A is a negotiation tool, but it changes the cap table for everyone, including you as a founder.

First-hand lessons: oversized seed pools (20% or more) that aren’t fully used create a hidden tax on Series A. The math punishes you when you raise again because you dilute more than expected. A lean approach works better unless you have concrete hiring commitments that justify a bigger pool.

A few practical takeaways

• Nail your hiring plan for 18-24 months, then size the pool to cover it. Do not guess.
• Consider sector norms: Deep Tech/Biotech push toward 15%+, SaaS around 10-12.5%.
• Plan for a Series A top-up pre-money; expect investors to push for it.
• Buffers matter: 25% for seed, 30-40% pre-seed if uncertain.
• Use the pool to secure critical hires early, not as a flexible reserve.

Author notes and perspective: I have observed this in dozens of rounds. The right pool size reduces dilution issues later and supports key hires. Data backs this up: Carta’s 12.5% seed median, Series A targeting around 10%, and 5-8% for Series B+.

If you want to improve your plan, run the numbers with your hiring forecast. Do not guess, do not over-promise. Contact me if you need guidance on your pitch.

I hope this is helpful (but you should lock this in now if you are raising soon). The pool size sets the tempo for your next 18-24 months. A close contact described their pool approach as plan, top up early, and protect dilution. Rely on a clear, data-informed plan. Contact me if you need guidance on your pitch.

Daimen Blaine

I’m Daimen Blaine. I’m not a guru, and I definitely don’t call myself a “visionary,” but for as long as I can remember, I’ve been obsessed with two things: world-changing ideas and the crazy people bold enough to chase them. That’s why I write. Because every startup is a story waiting to be told - and if there’s a funding round behind it, even better.

My journey didn’t start in Silicon Valley (I wish), but in a co-working space filled with burnt coffee, impromptu pitches, and that weird energy that hovers when nobody knows what they’re doing, but everyone’s hungry. I tried building my own startup (spoiler: it flopped), poured my time into others, learned the hard way - and now, I write about all of it. The stuff no one tells you and the things everyone’s chasing.

Here I'll be profiling groundbreaking founder profiles, deep dives into million-dollar rounds, real-world guides to getting investors on board, and yeah, the occasional rant about startup culture. Because let’s be honest - the tech world is brilliant... but it’s also chaotic, exhausting, and often, straight-up contradictory.