Unicorns...

In technology, much like fiction, unicorns are rare, mythical creatures, which most only ever dream of capturing.

In tech start-up land "unicorn" has become the moniker for a company that has achieved the valuation of $US1 billion, and in the United States only about 0.14 per cent of tech start-ups ever reach that status. 

Read more: http://www.afr.com/technology/are-envato-canva-campaign-monitor-aconex-and-rokt-the-next-atlassian-20150930-gjydrc#ixzz3nqJRZSr0