CNBC has released its sixth annual Disruptor 50 list, a ranking of top innovator companies that are changing the world. The list is topped by SpaceX, a company founded by Tesla Inc. (TSLA) CEO Elon Musk, which designs, manufactures and launches advanced rockets and spacecrafts. Using a combination of variety of technologies like artificial intelligence, machine learning, robotics and Internet of Things (IoT), the Hawthorne, California-based company aims to provide space exploring possibilities and space vehicle launch services to individuals, governments, and businesses. It has an estimated valuation of $28 billion. (See also: How SpaceX Reinvented the Rocket Launch Industry.)

Dara Khosrowshahi-headed Uber took second place in the coveted list, up from No. 19 in last year’s ranking. Beyond being considered the standard app-based ride hailing service, Uber jumped in this year’s ranking due to its new plans, which include car-sharing vehicles, car rentals, public transportation such as buses and trains, and the potential from a recent acquisition of a dockless bike company called Jump. The company also plans to “share more of its traffic-pattern data with cities,” in order to better engage with authorities for a win-win. The company has an estimated valuation of $69.6 billion.

Third-placed Airbnb enters its 11th year of operations. Beyond the standard online marketplace for home sharing, it continues to offer new initiatives to keep the participants engaged. Its launch of “Experiences,” which allows guests to explore a surrounding with the expertise of the locals, makes it a unique proposition. With larger migration to cities, patrons are expected to spend more on real experiences than standard sightseeing and possessions. It has also launched different tiers to serve high-end customers, called "Airbnb Plus" and "Beyond by Airbnb." The company has an estimated valuation of $31 billion. (See also: How Airbnb Makes Money?)

China's Disruptors

China’s Uber, Didi Chuxing, grabs the fourth spot. It serves 25 million rides a day, about twice as many as Uber, Lyft and all the other car-hailing apps combined. The company is active in the driverless car and the food-delivery space as well. The company has an estimated valuation of $56 billion and has backing from SoftBank. (See also: Didi Gets California OK to Test Self-Driving Cars.)

Lyft, another Uber rival in the U.S., stands at No. 5. The San Francisco-based company increased its national ride-sharing market share to 35%, up from 20% 18 month ago. During 2017, it offered 375.5 million rides, a rise of 130 percent over those served in 2016. It teamed up with Baltimore Bike share to offer both bikes and ride-sharing pickups, and has plans for getting into autonomous driving. The company has an estimated valuation of $11.7 billion.

Sixth-ranked Grab made headlines after acquiring Uber's Southeast Asia operation in late March. The Singapore-based ride-sharing unicorn has an estimated valuation of $6 billion. It serves 200 cities in eight Southeast Asian countries.

Other companies figuring in the coveted list include:

  • 23andMe, a privately held personal genomics and biotech firm based in Mountain View, California, that markets genetic reports on an individual's risk for a selected list of diseases.
  • Udacity, an online education platform that offers a variety of tailored courses and has partnerships with the likes of Amazon, Google, AT&T and Facebook.
  • Rent the Runway, a platform that allows patrons to rent and use their desired items for a few days.

Cryptocurrency also finds a spot in the top 10 list. The 10th spot is held by Coinbase​​​​​​​, a leading U.S. marketplace for trading and investing in digital currencies. (See also: Coinbase: What Is It and How Do You Use It?)