Employee Option Pools in SaaS: Size, Structure, and How to Avoid the Option Pool Shuffle

Employee option pool structure and dilution mechanics in SaaS companies

What Option Pools Are and Why They Matter More Than You Think

An option pool is a reserve of shares set aside for employee equity compensation. Most SaaS founders think option pools are simply pools of shares they set aside for future hiring. This is partially correct. The critical nuance is when the pool is created, which determines who bears the dilution cost. A pool created before investor capital arrives (pre-money) is carved out of founder shares and does not dilute investor ownership. A pool created after investor capital arrives (post-money) dilutes all existing shareholders equally with the investor. This distinction is the option pool shuffle, and it is responsible for more founder value destruction than most founders realise.

The reason option pools matter is that they do not require any capital raise. You can create a pool and dilute founders without any external money entering the company. An investor who demands a 15% post-money option pool in a £20M Series A round (£8M raised) is requiring founders to issue £3M of equity to employees without founders receiving any capital. The investor is purchasing shares at £2.50 per share (£8M divided by 3.2M shares issued). Founders, via the option pool, are being diluted at the same price even though they are not receiving the cash. This is mathematically equivalent to founders investing £3M additional capital in the company at the investor's price.

Pre-Money vs Post-Money Pools: The Shuffle Explained

Let us illustrate with a simple example. You have a company with 10M shares issued to founders. You are raising a Series A. Your Series A investor proposes to invest £8M for 2M new shares. The question is when the option pool is created. If created pre-money (before the investor arrives), the pool is carved from your 10M founder shares. If the pool is 10% of post-money capitalisation (12M shares total), the pool is 1.2M shares, but these come from your founder shares. You are diluted from 100% to 87% (8.8M of 10.1M shares). The investor receives 2M of 10.1M = 19.8%. The option pool is 1.2M of 10.1M = 11.9%.

If the pool is created post-money, the sequence is different. The investor invests £8M for 2M shares. This increases total shares from 10M to 12M. Then, you create a 10% post-money option pool of 1.2M additional shares. Total shares outstanding are now 13.2M. Founders own 10M of 13.2M = 75.76%. Investor owns 2M of 13.2M = 15.15%. Option pool owns 1.2M of 13.2M = 9.09%. Compared to the pre-money alternative, founders are diluted an additional 11.2 points (87% to 75.8%). This is the option pool shuffle. The post-money pool requires founders to bear the dilution cost, not the investor.

The shift from pre-money to post-money pools is the single largest hidden wealth transfer from founders to investors at Series A and beyond. Most founders do not negotiate this point because they do not understand it. Your Series A term sheet will almost certainly propose a post-money pool. Push back aggressively. A pre-money pool costs you significantly less founder equity for the same hiring capacity.

Typical Pool Sizes by Stage

Seed stage: 10-15% post-money option pools are standard. At seed, founders are raising small amounts (£500k to £2M), often from angels or early venture firms. Pools are larger (closer to 15%) because founders have not yet built teams and the pool will be needed for many early hires. A 15% post-money pool at seed is reasonable because it reflects early-stage hiring needs. Push back if investors demand 20%+ pools at seed. Standard market is 10-15%.

Series A: 10% post-money option pools are market standard. At Series A, you have established a core team and hiring velocity is known. A 10% pool is standard and should be non-negotiable. If investors demand 12-15% at Series A, push back and offer 10% post-money or a pre-money pool of equivalent size. The difference between 10% and 15% at a £20M Series A is 1M shares, which at £1-2 per share (series A prices) is £1-2M in founder value destruction.

Series B: 8-10% post-money option pools are typical. By Series B, hiring needs are more predictable and the pool can be smaller. Demand 8% unless your hiring plan requires more. Negotiate for pre-money pools at Series B. More sophisticated founders successfully negotiate pre-money pools at Series B, which costs significantly less founder dilution.

Post-Series B: pools remain 8-10% post-money or, increasingly for mature companies, pre-money pools are negotiated as standard. If you have reached Series C and beyond, your investor base is experienced and understands the option pool shuffle. Push for pre-money pools regardless of stage. By late stage, pre-money pools are common because both parties understand the economics.

Strike Price and 409A Valuations

When you grant options to employees, you must set a strike price. The strike price is the exercise price the employee pays to purchase the shares. For tax purposes, the strike price must equal the fair market value of shares at the time of grant. This is determined by a 409A valuation, a third-party appraisal that determines the fair market value of your shares. If the 409A valuation is £1 per share and you grant options at £0.80 per share, the Internal Revenue Service will view the £0.20 discount as taxable compensation.

The 409A valuation increases after each funding round. A £2M post-money seed valuation means shares are worth roughly £0.20-0.40 per share (depending on dilution). A £20M Series A valuation means shares are worth roughly £2-3 per share. An £80M Series B valuation means shares are worth roughly £8-12 per share. Each increase in 409A valuation makes strike prices higher, making options less valuable for employees. An engineer who received options at £0.50 per share at seed is in-the-money if the next round values shares at £3. An engineer who receives options at £3 per share at Series A is in-the-money only if Series B values shares above £3. This dynamic discourages mid-stage hiring because options become less valuable relative to cash compensation.

Manage 409A valuations carefully. Many founders are unaware that 409A valuations are public documents filed with the company and can be requested by potential acquirers during due diligence. A low 409A (below market) creates tax risk and conflicts. A high 409A (above market) makes options worthless for employees. Target 409As that are 20-30% below the last funding round valuation. This creates options that are meaningful but not toxic. Update 409As annually or after significant company developments (large contract wins, fundraising milestones). Stale 409A valuations are red flags to investors.

Vesting Schedules: Standard 4-Year Cliff

Options typically vest over four years with a one-year cliff. This means an employee must stay for one year to receive any options. After the one-year cliff, options vest monthly (or quarterly) over the remaining three years. An employee who leaves after six months receives zero options. An employee who leaves after 18 months receives 4.5 years worth of vesting ((12+6 months) vesting / 48 months total). This structure aligns employee incentives with company success and reduces the cost of early departures.

The four-year structure is market standard and reflects the median SaaS employee tenure. Some founders propose two-year vests or three-year vests. Two-year vests are rarely acceptable to investors; they create too much option value for short-tenure employees. Three-year vests are negotiable and sometimes accepted for early-stage companies with strong founders, but four-year is expected. Do not propose structures shorter than four years.

The one-year cliff is market standard and strongly recommended. It protects against hiring failures. If you hire an employee who leaves after eight months, you are protected from vesting 67% of the option grant. Without a cliff, employees could demand accelerated vesting or special treatment. The cliff makes the outcome predictable and objective.

Grant Levels by Role and Seniority

Option grants should scale with seniority and impact. Early engineers hired at seed typically receive 0.5-1.5% of the company (post-dilution). Mid-stage engineers hired at Series A typically receive 0.05-0.1% of the company. Senior leadership (VP engineering, VP sales) hired at Series A typically receive 0.2-0.5% of the company. The principle is that early joiners who bear more risk receive larger grants, and later joiners who have less risk receive smaller grants.

Use an option grant spreadsheet that ties grants to role, seniority, and company stage. Do not grant options ad-hoc based on negotiation. Consistency matters because option recipients will compare their grants to peers. A transparent, documented grant policy protects against accusations of favouritism or discrimination.

Managing the Pool: Reserves and Refresh Cycles

As you hire, your option pool depletes. A 10% pool at Series A with 20 new hires (averaging 0.15% per hire) will deplete to 7% by Series B. Investors expect to refresh the pool at each funding round. A Series B term sheet will typically include a refreshed option pool (new 8-10% for Series B hiring). The refresh dilutes all existing shareholders equally, which is fair. Some investors aggressively propose refreshes that are larger than needed, using the pool to disguise additional investor ownership. Negotiate pool refreshes carefully. The pool should reflect your actual hiring plan for the next 18 months, not your theoretical hiring capacity. A 20-person startup raising Series A does not need a 15% pool sized for 40 hires.

Key Takeaways

Option pools allow employee equity compensation without founder share sales
Pre-money pools protect founders; post-money pools dilute founders equally with investors
The option pool shuffle shifts dilution cost to founders without raising capital
Typical pool sizes: 10-15% seed, 10% Series A, 8-10% Series B
Strike prices tie to 409A valuations; high 409As make options worthless for employees
Standard vesting is four-year with one-year cliff, protecting against early departures
Grant levels should scale with seniority: early joiners receive 0.5-1.5%, later joiners 0.05-0.15%