It takes a trend-spotter to reimagine the world and come up with a bright idea to change things. These futurists all have passions that drive their curiosity. For a look at how they turned their inspirations into reality, one merely has to look at the 2015 CNBC Disruptor 50, our third annual roundup of the country's most ambitious and innovative private companies revolutionizing their industries—and the economic ecosystem.
The common denominator? All of these companies entered traditional sectors and turned them upside down. About half of this year's disruptors are last year's alumni that have inspired incumbent companies to adopt their new business models.
Read MoreFULL LIST: 2015 DISRUPTOR 50
For this year's list, CNBC updated our selection process. Instead of relying solely on submissions from venture capital firms through the National Venture Capital Association, as we did in years past, we opened nominations to the public at large. Nominees were required to submit a detailed analysis of companies for consideration that included key quantitative and qualitative information. This led us to expand the universe of potential contenders beyond those favored by their VC backers. As a result, we received nominations directly from entrepreneurs in the U.S. and abroad.