In the sixth annual Disruptor 50 list, CNBC features private companies — from biotech and machine learning to transportation and retail and even exploring outer space — whose innovations are changing the world. These forward-thinking start-ups have not only identified unexploited niches in the market that have the potential to become billion-dollar businesses, a majority of them already are billion-dollar businesses. A startling 33 disruptors this year are unicorns that have already reached or passed the billion-dollar mark.

Unseating corporate giants is no easy feat. But we ranked those venture capital–backed companies doing the best job. In aggregate, these 50 companies have raised nearly $78 billion in venture capital at an implied Disruptor 50 list market valuation of more than $350 billion, according to PitchBook data. Many already are part of our daily lives, whether or not we know it. Read more about the trends that stand out in the 2018 list ranking — from drones and genes to the battles for control in the rapidly growing ridesharing, lodging and cryptocurrency industries — and the methodology used to select this year's Disruptor companies.