A whopping 31% of unicorns listed by CB Insights are worth exactly $1B. Jeremy Liew, from Lightspeed Venture Partners, noted in a tweet that it’s “potentially not a coincidence”.

There’s much to be gained by joining the fabled club, not least of which is appearing on these hallowed lists which in turn generate their own momentum.

But the extra valuation comes at a cost of protected rights for the last investors setting the price. As the adage goes: you set the valuation, I’ll set the terms.