Henry Blodget:

For the past 15 years or so, ever since the tech industry began its recovery from the dot-com bust, observers have rushed to declare a new “bubble.”
 With each successive increase in the valuations of companies like Google, Facebook, Twitter, Uber, Pinterest, Snapchat, skeptics have dismissed the growth as a “fad” and the extraordinary and real value created as a delusion.
 For the past 15 years, these skeptics have been wrong.
 And insofar as they dismiss today’s tech environment as a “bubble,” they’re still wrong. Today’s investment climate is still a far cry from the bubble years of the late 1990s.