The power law: why one investment has to return the whole fund.

Venture returns are not spread evenly. In a typical early-stage portfolio, around half the companies return less than the money put in, a handful return a few times their money, and one or two return more than all the others combined. Statisticians call this a power law. VCs live by it.

What a portfolio really looks like

Picture a fund that backs 30 tech startups with equal cheques (an illustrative mix, not data):

• 15 fail or return a fraction of the money.
• 6 return roughly their money back.
• 5 return two to five times.
• 3 return ten to twenty times.
• 1 returns 100 times.

That one outlier often produces more than everything else in the portfolio put together. Remove it and a good fund becomes a poor one. Run it yourself in the VC portfolio simulator.

Why VCs ask for 10x

If half the portfolio returns little or nothing, the winners must make up for them and still deliver a strong overall return. So at the moment of investing, a VC needs to believe each company could return at least ten times their money. Most will not. That is understood. But a company that could only ever return two or three times cannot fix the maths, however safe it looks. This is the 10x return model we wrote about in The 10x return model of VC funding.

Can you return the fund?

Many partners go further and ask whether a single investment could return the entire fund. The sum is simple:

Exit value needed = fund size ÷ the stake the VC owns at exit.

A £50m fund that owns 10% of your company when it is sold needs a £500m exit to get £50m back. Owning 7.5% after later rounds dilute it, the figure rises to about £670m. Try your own numbers in Can you return the fund?

What this means for tech founders

• Market size matters more than polish. A VC is buying a chance at a very large outcome. Show how big the business could become, built bottom-up from real customers and prices. Our market sizing guide shows how.
• Match the fund to the exit. A £20m exit is a life-changing result for tech founders, and irrelevant to a £300m fund. Smaller funds, angels and syndicates can make good money on outcomes larger funds cannot.
• Expect pressure to grow fast. An investor who needs an outlier will often prefer a bold plan with more risk over a steady plan with less.
• A no is not a verdict on your business. Plenty of excellent, profitable tech companies are not venture-shaped. That can be a strength: you keep more ownership and more control.

General information, not financial, legal or tax advice. Figures marked as rules of thumb vary by fund, sector and market conditions.