Aileen Lee
Founder & Managing Partner, Cowboy Ventures
Coined the term "unicorn" and built one of the first data-driven seed funds.
Aileen Lee spent over a decade at Kleiner Perkins, working hands-on with companies from Series A through IPO, including Bloom Energy, Rent the Runway and Trendyol.
In 2012 she founded Cowboy Ventures, a seed-stage fund backing teams reimagining work and personal life. In 2013 she published the research that coined "unicorn" for billion-dollar startups, turning a loose pattern into a dataset the industry still cites.
Cowboy invests at seed across enterprise software, fintech, security, health and AI-native tooling rather than committing to a single vertical. Lee has returned to the unicorn dataset repeatedly in the years since, re-running the study against the original cohort to test which of its findings actually held.
How she invests
The defining habit is measurement rather than prediction. The 2013 study did not forecast anything — it counted how often billion-dollar outcomes had actually occurred and what the companies producing them had in common, against an industry that had been repeating the same beliefs without checking them. Re-running that work years later, against a cohort whose outcomes were by then known, is a form of self-scoring that venture capital almost never does in public.
What an individual investor can take from it
The transferable practice is not the terminology, it is the scoring. Write down what you believe about a category, state what evidence would prove you wrong, and revisit it a year later with the outcomes in hand. Most individual portfolios are never scored this way, which is exactly why their owners cannot separate a good decision from a lucky one — and those two require completely different responses the next time round.
Where the lesson stops
Scoring your own decisions is much harder at individual scale than at fund scale. A seed fund makes dozens of comparable bets a year, which is enough for patterns to emerge; an angel making three or four a year will not accumulate a statistically meaningful record within a decade. Keep the record anyway, but read it as a check on your reasoning rather than as evidence about your skill.
Coined the term "unicorn" for billion-dollar startups.
Sources
Facts here reflect public reporting at time of writing — roles and fund affiliations change; verify current details directly with Cowboy Ventures.