11 billion-dollar start-ups the world is waiting on to go public

Since the inception of the CNBC Disruptor 50 list five years ago, seven companies have stayed on the list for all five years, wooing us with innovative ideas and their ability to scale quickly and reshape industries. These seven companies raised more than a combined $25 billion from more than 400 investors, and they have a market valuation of about $120 billion, according to PitchBook.

One thing they haven't done: gone public.

Several are household names, operating in nearly every country, with billions of users — and poised for an IPO. A few are biding their time and playing coy with IPO comments. And a few simply don't buy into the allure of the traditional Wall Street offering anymore as they gobble up tons of money in private deals.

Eleven start-ups worth more than $1 billion from the 2017 CNBC Disruptor 50 are on the IPO watch shortlist — at a time when the public-offering market is heating up.

With 2017 on track to have the first annual increase in IPOs in four years — the Renaissance IPO ETF (IPO) is up 18 percent year-to-date — the stage is set for these tech juggernauts to raise lots of money from investors through an offering.

"We're in the best of all IPO markets," Renaissance Capital's Kathleen Smith recently told CNBC. "If you're not moving forward, you need to have your head examined."

Here's a look at how the big companies on this year's CNBC Disruptor 50 list are posturing themselves amid the reports about taking the leap to being a public company.

Whether you're looking to spend an evening like Tarzan in a jungle treehouse or Cinderella in a majestic castle, Airbnb more than likely has you covered with its more than 3 million worldwide listings.

Operating in more than 97 percent of the world's countries, the Disruptor recently expanded its online marketplace for home- (or room-) sharing by launching Trips, which allows guests to not only book a place to stay but also choose from thousands of experiences that are unique to the host city or country.

The company, founded in 2008, reportedly turned a profit in the last half of 2016 and anticipates it will remain profitable for the remainder of this year. Despite growing popularity and recent successes, we don't know yet when — or if — Airbnb will take the plunge and file for an IPO.

"We are working on making sure the company is ready to go public, and I've said it was a two-year project," Airbnb co-founder and CEO Brian Chesky told an audience earlier this year at the Economic Club of New York. "We're probably about halfway through that project, as far as just being ready to go public."

Airbnb co-founder Nathan Blecharczyk told CNBC on Tuesday after being named the No.1 Disruptor in 2017, "We don't have any plans for an IPO. We don't have a need for that capital right now."

Airbnb has raised more than $4 billion from investors, including Fidelity Investments, Andreessen Horowitz and SV Angel and has a market valuation of $31 billion, according to PitchBook.

Brian Chesky, Airbnb co-founder and CEO

Bloom Energy is working to supply its customers — including Apple, eBay and Fedex — with clean and reliable energy by using fuel cells to convert natural gas into electricity.

Over the past year, the company has supplied its fuel cells to power IKEA stores on both coasts and to Morgan Stanley's headquarters in New York, enabling the companies to reduce their carbon footprints.

In late 2016 the Wall Street Journal reported that Bloom Energy filed a confidential registration with the SEC for an IPO. Companies with less than $1 billion in revenue can register privately with the SEC rather than publicly file a traditional S-1, where investors would get a peek at financials.

The company has raised more than $1 billion from investors, including Kleiner Perkins Caufield & Byers, Goldman Sachs and New Enterprise Associates and is valued at more than $3 billion, according to PitchBook. But it's around for more than 15 years and has been flirting with the IPO market on and off for a while.

K. R. Sridhar, co-founder and CEO

Something's heating up in the oven over at Blue Apron, and we're not talking about the company's on-demand meal kits ranging from roasted onion miso ramen to seared peppercorn steaks.

Blue Apron reportedly recently brought three new cooks into their kitchen — Goldman Sachs, Morgan Stanley and Citi — to lead an initial public offering as soon as this fall.

Founded in New York in 2012, Blue Apron has raised more than $193 million with the backing of Bessemer Venture Partners, Fidelity Investments and Stripes Group, to name a few, and is valued at $2 billion, according to PitchBook.

Matt Salzberg, Blue Apron co-founder and CEO

The cloud-based file-sharing company Dropbox recently hit revenue-and-profit milestones that co-founder and CEO Drew Houston was aiming for before even thinking about taking his company public.

With more than 500 million registered users worldwide, including 200,000 business customers, the company reportedly brings in more than $1 billion in revenue on an annual basis.

Dropbox's closest and fiercest competitor, Box, went public in 2015. Its shares are up more than 30 percent this year, and it is still above its IPO listing price of $14. But Box shares are down 20 percent all-time based on its first-day opening trade.

Dropbox recently secured a $600 million credit line from six banks, led by JPMorgan Chase, bringing the company's market valuation to $10 billion, according to PitchBook.

Drew Houston, Dropbox co-founder and CEO

Mum's the word at Palantir Technologies, a company whose work with the U.S. government — including the Federal Bureau of Investigation and Central Intelligence Agency — and top Wall Street firms is known to very few.

Due to the high-value and oftentimes classified nature of intelligence received, ranging from counterterrorism to financial fraud, the company may face a difficult scenario that they've never had to go head-to-head with if they decide to go public: revealing the secretive financial data that's been kept under close watch since its founding more than 10 years ago.

However, late last year in an interview with the Wall Street Journal, CEO Alex Karp said the company is "positioned so [it] could go public," as the "aggregate business will be profitable next year."

Alex Karp, Palantir Technologies CEO

Ever since Ben Silbermann and Evan Sharp launched Pinterest in 2010, more than 175 active users around the world, as well as 1 million businesses, have been "pinning" content to virtual bulletin boards ranging from dessert recipes to engagement rings.

The company gathers its revenue mainly in the form of ad sales across its desktop and mobile platforms — roughly $300 million dollars last year, nearly tripling 2015's total — and has raised more than $1.3 billion from investors, including Andreessen Horowitz, SV Angel and Bessemer Venture Partners, bringing the company's valuation to $11 billion, according to PitchBook.

Recode recently reported that Pinterest won't IPO "soon" but that hiring its first CFO, Todd Morgenfeld, from Twitter back in October, and Facebook's former monetization director, Tim Kendall, who is overseeing revenue efforts, suggest it is at least planning for a deal.

Silbermann has given no indication in public comments that a deal is coming soon, and Pinterest told Recode: "We don't have any current plans for an IPO right now, because we're focused on growing the business."

Ben Silbermann, Pinterest co-founder and CEO

It may be a long shot — or moonshot — to say SpaceX is close to IPO liftoff, but hey, it's Elon Musk, so you never know.

The Hawthorne, California-based company has been working since 2002 to design, manufacture and launch rockets and spacecraft into orbit with the goal of cutting costs of space travel and making the galactic frontier accessible to the average Joe — Musk actually thinks a Mars colony will be the only way to save humanity. Musk and SpaceX came one step closer to this goal in March when they landed the first reused Falcon 9 rocket on the drone ship "Of Course I Still Love You."

In total, SpaceX has raised more than $1 billion from investors — which include Google and Fidelity — and have 70 missions booked for commercial customers, as well as NASA, representing $10 billion in contracts. According to PitchBook, Musk's company has a valuation just north of $10 billion.

When asked earlier this month to comment on the rumors that SpaceX was preparing for an IPO, company president Gwynne Shotwell told Reuters the rumors are "not true."

Elon Musk, SpaceX founder and CEO

Spotify has more than 50 million paid subscribers — making it bigger than rivals Apple Music, SoundCloud and Google. The digital streaming music service operates in 60 countries and is poised for further growth.

While the low cost of unlimited music streaming keeps listeners happy, some artists complain they are unfairly compensated as they receive a check only based on the number of streams downloaded through the service.

Reports are spreading that Spotify will go public this year, but not through a traditional IPO. CNBC recently reported that Spotify is pursuing a direct listing that is expected between the fourth quarter of 2017 and first quarter of 2018 on the NYSE. Morgan Stanley, Goldman Sachs and Allen & Co. are advising on the listing, sources told CNBC.

Investors have poured more than $2 billion into the company that's valued at more than $12 billion, according to PitchBook.

Daniel Ek, Spotify co-founder and CEO

SurveyMonkey is responsible for collecting more than 3 million online survey responses daily, with clients ranging from Fortune 500 companies to private start-ups, academic institutions and ordinary individuals.

The company has raised more than $1 billion from investors such as T. Rowe Price, Spectrum and Tiger Global Management, with a valuation of about $2 billion, according to PitchBook.

In late 2016, CEO Zander Lurie told TechCrunch that his company is more than likely to go public after 2017, explaining that they want to do it on "their own terms."

"We have some exciting product development in place, and we want to get more traction and more visibility," Lurie said. "That will put us in a great position to go public on our own timeframe, likely after 2017."

Zander Lurie, SurveyMonkey CEO

At a private valuation of $68 billion — bigger than Ford, GM or Tesla — this will be a big deal.

But Uber's recent streak of negative headlines isn't helping. Claims about a toxic work culture, a legal battle over allegedly stealing trade secrets from Alphabet, and deceptions the company has engaged in against regulators and Apple, have all plagued Uber this year. The IPO market may have to wait. But for a company whose footprint is found in more than 500 cities and 75 countries worldwide, there doesn't seem to be a rush to go public, anyway.

Uber boasts the most impressive financial benchmarks of any company on the 2017 Disruptor 50 list, with investors backing the company with nearly $15 billion. It finally revealed some financials this year to combat the negative news flow. In the fourth quarter of 2016, passengers spent $6.9 billion on Uber rides (what Uber calls "gross bookings"). It netted $2.9 billion in revenue and a loss of $991 million. Uber more than doubled its bookings, but it burned through a historic amount of cash to do it.

Fellow Disruptor 50 competitors Lyft, which tripled bookings last year, and Grab are growing as well.

Travis Kalanick, Uber Technologies co-founder and CEO

WeWork, the New York City-based company providing shared work spaces for entrepreneurs, freelancers and small start-ups, has been quickly expanding around the globe, with more than 80,000 people enjoying lavish offices with amenities ranging from arcade games to free beer on tap.

In February the company raised $300 million from Japan's SoftBank, led by Masayoshi Son, the same bank that late last year promised then President-elect Donald Trump it would invest $50 billion in the United States and create 50,000 new jobs. The investment brings WeWork's total funding to nearly $2 billion, giving the company a valuation of $18 billion, according to PitchBook.

At last year's Fortune Brainstorm Tech conference, WeWork CEO Adam Neumann said, "One thing we're not afraid of is going public." But he gave no hint on timing.

Adam Neumann, WeWork co-founder and CEO