One of the most frequent questions is what is the optimal number of startup co-founders?

This is a tough question given there are so many factors at play.

Ilya Strebulaev, Professor at Stanford Graduate School of Business | Venture Capital & Private Equity, has addressed the question.

Here is evidence on the number of co-founders from unicorns. For the sample of 531 US unicorns, he identified 1,356 co-founders.  About 80% of unicorns have more than one founder. Having two or three co-founders is most common, and just 7% of unicorns have more than four co-founders.

A small number of unicorns do have many co-founders, however. Palantir Technologies has 5, Fair.com has 6, ThoughtSpot has 7, Hortonworks has 8, Wheels Up has 9, and Juno Therapeutics, Inc. has 10!

This research has been done with the help of the Stanford University Graduate School of Business Venture Capital Initiative. Many other factors – such as how co-founders complement each other – are also important