Article at Vator: The USD1B valuation club became super crowded in 2014

http://vator.tv/news/2015-01-14-the-1b-valuation-club-became-super-crowded-in-2014

With valuations jumping so high, the USD1 billion club is getting easier and easier to get into. In 2014 alone, 38 different companies entered the USD1 billion club, according to a report from CB Insights. That is more than the three previous years, when only 22 companies made it combined
https://www.cbinsights.com/blog/billion-dollar-valuation-startups-2014/

There is a large dotcom bubble fueled by venture investment funds, investors who are dragging other investors to continue investing until they can sell shares of the company and recover leveraged money, but the last holder of shares is going to lose. 
Please see: tech space that is out of control: WhatsApp 
http://onlinedatingsoundbarrier.blogspot.com.ar/2014/02/tech-space-that-is-out-of-control.html 

"Social media faces doubts after latest round of results"
 http://onlinedatingsoundbarrier.blogspot.com.ar/2014/05/social-media-faces-doubts-after-latest.html
Many companies had been operating at a loss for years!!! They will never be profitable.
http://onlinedatingsoundbarrier.blogspot.com.ar/2014/12/incredible-uber-raises-another-usd12.html
http://onlinedatingsoundbarrier.blogspot.com.ar/2014/10/article-vc-funding-falls-30-tech-ipos.html
http://onlinedatingsoundbarrier.blogspot.com.ar/2014/05/pinterest-raises-new-round-of-usd-200.html