http://www.newsweek.com/coinbase-billy-markus-forum-post-1584128

Coinbase CEO Brian Armstrong once tried to recruit help in building the crypto trading platform now worth $60 billion—but was batted aside.

In a comment posted to the HackerNews forum in 2012, Armstrong, posting via an anonymous throwaway account, detailed an "awesome prototype" he was working on that he thought "has a good shot at changing the world."