Facebook, Amazon (NASDAQ: AMZN), Apple (NASDAQ: AAPL), Netflix, and Alphabet's (NASDAQ: GOOGL)(NASDAQ: GOOG) Google were coined the "FAANG" stocks due to their shared ability to generate astounding shareholder returns over a relatively short timeframe. Over the last five years, their shares have generated total returns of 187%, 533%, 210%, 631%, and 190%, respectively. Ten-thousand dollars invested evenly among them five years ago would be worth over $45,000 today. Finding a new grouping of stocks that could perform so well isn't easy, but there are some definite candidates for consideration. So which stocks could be "the next FAANG index?" I think Spotify (NYSE: SPOT), Carvana (NYSE: CVNA), Amazon, and Zillow Group (NASDAQ: Z)(NASDAQ: ZG) -- the SCAZ stocks -- are as good a bet as any. Amazon is a repeat from the original FAANGs, but deservedly so, given the enormous markets it is working to excel in. Image source: YCharts. 1. Spotify Spotify is the world's largest audio streaming platform, with 248 million monthly active users (MAUs), including 113 million paying Premium subscribers, as of the end of September. Both user metrics grew 30% and 31%, respectively, last quarter. Despite this solid growth, the company still has a very small share of a 3 billion-plus smartphone addressable market to tap into, so the growth potential ahead is big. While streaming label-controlled music isn't very profitable yet, the company's aggressive expansion into podcasting and its two-sided marketplace should contribute to rapidly growing profits. For example, the recently released Streaming Ad Insertion tool is bringing targeted and measurable advertising to podcasts for the first time, which should significantly increase ad pricing. Skeptics point out competition from Apple Music, Amazon Music, YouTube, SiriusXM's Pandora, and others -- but Spotify is outperforming all of them. For example, the No. 2 streamer, Apple Music, last reported a subscriber figure in June when it said it had over 60 million subscribers. Since then, Spotify's grown its MAUs and Premium subscribers by 38% and 36%, respectively. If Apple had impressive or even comparable numbers to report since then, it's unlikely the company would be keeping it a secret. Spotify thinks its user engagement is twice that of Apple Music's and three times that of Amazon Music's. That's part of why Spotify believes its churn rate (which includes subscriber cancellations) is half that of Apple Music. Meanwhile, Pandora's user base continues to shrink. Some investors worry the major music labels have such market power that they will capture most of the industry profit pool for themselves. But as Spotify continues to grow and diversify its business away from just music, and as the labels grow increasingly reliant on Spotify for their revenues, bargaining power in the industry should only shift in Spotify's direction. 2. Carvana Carvana invented a better way for consumers to buy used cars and has been rewarded with astonishing growth. Seven years after its founding, it's still growing revenues by over 100% each quarter. The company offers a selection of over 27,000 used cars for sale, entirely online, and delivers them to customers' doors or to their patented vending machines to be picked up. Not only is it a better car buying experience, but management claims its cars are typically $1,000 cheaper than those sold by its competitors. Carvana's opportunity is vast because it has only about 0.5% of the estimated $800 billion per year U.S. used-car market. The market is extremely fragmented with CarMax (NYSE: KMX), the used car leader, having less than 2% market share nationally, and with the top 100 used car retailers having a combined 7% market share. Interestingly, Carvana's market share in its oldest market, Atlanta, was 1.94% at the end of 2018, and is probably closer to 2.5% today. Since Carvana's market share in its oldest market is already higher than CarMax's share nationally, Carvana should become the used car king if the rest of the country continues to follow Atlanta's lead. At the same time, there's no clear upper limit for Carvana's market share, because its model has fewer constraints on growth than traditional used car retailers, which have to build out hundreds of retail locations in order to grow. Carvana is rewriting the rules of the game in a huge market. Image source: Getty Images. 3. Amazon Amazon is one of the original FAANG stocks, but still has so much growth potential left that I have no choice but to include it in this group as well. Despite Amazon's enormous success to date, it still controls just 1.2% of global retail sales. Similarly, Amazon Web Services (AWS) leads the Infrastructure-as-a-Service market and is already a $36 billion annual run-rate revenue business. Yet that is only 1% of the $3.7 trillion total IT infrastructure market it is going after. Both businesses are only scratching the surface of their opportunity. There is also a rapidly growing and high-margin online advertising business, as well as a slew of other emerging businesses. On top of that, Amazon relentlessly invents new businesses from scratch. We'll probably be talking about the company's huge global logistics business one day or its dominant healthcare business or some other big idea it is working on that we don't even know about yet. That pioneering culture of invention is a big reason why Amazon is a repeat from the original group. 4. Zillow Group Zillow Group is using its massive 196 million MAU base to completely reinvent the home-buying and selling process. By buying and selling homes directly through Zillow Offers, the company is positioning itself at the center of the home real estate transaction. That should open up large adjacent revenue opportunities, including mortgage origination, title insurance, homeowner insurance, design and renovation services, moving services, and a variety of other similar opportunities. Over time, Zillow could evolve into a real-time marketplace of homes where buyers can purchase a house seamlessly with one click. If Zillow can create that marketplace, it should become enormously profitable. These companies find profit by finding a better way Each of the FAANG stocks invented a new and/or better way of doing something, whether it was social media, e-commerce, smartphones, streaming video, or search. Similarly, the SCAZ stocks are pioneering better ways of streaming audio, selling used cars online, e-commerce/cloud/and everything else, and buying and selling residential real estate. Just like the FAANGs, each of these businesses have 1) a tiny market share of an enormous market, and 2) competitive advantages necessary to successfully grow into those markets. Stock investors should take notice. 10 stocks we like better than Spotify TechnologyWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the ten best stocks for investors to buy right now… and Spotify Technology wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of December 1, 2019 John Mackey, CEO of Whole Foods Market, an Amazon subsidiary, is a member of The Motley Fool’s board of directors. Suzanne Frey, an executive at Alphabet, is a member of The Motley Fool’s board of directors. Randi Zuckerberg, a former director of market development and spokeswoman for Facebook and sister to its CEO, Mark Zuckerberg, is a member of The Motley Fool's board of directors. Andrew Tseng owns shares of Alphabet (C shares), Amazon, Carvana Co., Facebook, Netflix, Spotify Technology, and Zillow Group (A shares). The Motley Fool owns shares of and recommends Alphabet (A shares), Alphabet (C shares), Amazon, Apple, Facebook, Netflix, Spotify Technology, Zillow Group (A shares), and Zillow Group (C shares). The Motley Fool recommends Sirius XM Radio. The Motley Fool has a disclosure policy.Source