In the startup world, the odds of a company achieving a valuation of $1 billion or more is considered so slim, it's named after a mythical beast - the unicorn.
In the entire US, there are just 135 private companies that are valued at over a billion dollars or more. Of those, only ten became so-called unicorns in less than three years, setting the speed record for all the rest.
This list, based on data from Pitchbook, rounds up all of the companies in the US that hit the $1 billion valuation mark in record time.