A unicorn is a private startup valued at $1 billion or more. The term was introduced by venture capitalist Aileen Lee in a 2013 TechCrunch article about unusually successful technology startups.
Lee chose the mythical animal because billion-dollar private companies were exceptionally rare at the time. Her analysis found only a small number of such companies among thousands of technology startups founded over the previous decade.
A unicorn is not necessarily profitable, publicly traded, or independently valued through a stock-market price. Its valuation generally comes from a private funding round or another transaction. A decacorn is a related term for a private company valued at $10 billion or more, while a hectocorn refers to a valuation of at least $100 billion.