Filling your portfolio with long-shot stocks isn't a great idea. Such investments have high risks of failure and may not pan out. However, if you want to devote a small fraction of your portfolio (say 5% to 10% of its value) to stocks with huge upside and spread your bets out among them, then I think this can be a fun investment strategy. It's not for everyone. If you start having heart palpitations any time you see a stock you own fall by 50% or more, then I wouldn't encourage you to invest like this.
But if you're looking for the next big thing and can handle the stress, I think these three stocks offer massive upside and could deliver millionaire-maker returns.
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SoundHound AI
SoundHound AI (SOUN 4.11%) is combining audio recognition technology with generative AI. The application for this technology is massive, as it could potentially replace human employees in many types of business interactions. While SoundHound AI's primary success has been in the restaurant space, where it automates order-taking at drive-thrus, it's also starting to see some success in the customer service realm. Customer service reps represent a huge cost for many companies, and if a human-like AI bot can replace that, then SoundHound AI could experience massive growth.
NASDAQ: SOUN
Key Data Points
During the third quarter of 2025, SoundHound AI delivered 68% revenue growth. Yet its stock is down around 70% from its all-time high, and now trades at a fairly attractive 20 times sales.
That's a solid price for the stock, so this looks like a prime buying opportunity.
Nebius
Nebius (NBIS 3.53%) is positioned to produce incredible growth during 2026. It builds data centers, fills them with computing equipment built around Nvidia's processors, and then rents them. Its full-stack solution offers the ability for clients to get up and running with training and running AI models quickly, and it has become a wildly popular platform.
NASDAQ: NBIS
Key Data Points
Nebius ended 2025 with $1.25 billion in annual recurring revenue. That figure is expected to spike to between $7 billion and $9 billion by the end of 2026. That's monster growth, and if Nebius can deliver on its projections, I have no doubt that the stock will soar throughout 2026. If it can continue building out its computing footprint after 2026, it could be headed for even greater heights.
IonQ
IonQ (IONQ 3.47%) is a player in the technology that's expected to be the next big thing: quantum computing. Although quantum computing is a few years away at the earliest from being commercially viable, investing in these stocks now gives investors exposure to the most upside possible. IonQ is currently the worldwide leader in quantum computing accuracy -- the biggest hurdle this technology faces en route to wide commercial adoption.
NYSE: IONQ
Key Data Points
This makes IonQ the riskiest of the three, as it's still competing with numerous big-name and well-funded rivals (as well as a raft of other pure plays) to develop a broadly marketable product, but it also has the most upside if it works out. Only time will tell if IonQ emerges as one of the victors in this race, but I think it has incredible upside right now if it continues to push the limits of what's possible with quantum computing.
All three of these stocks will help accelerate your timeline to becoming a millionaire if they work out, but I doubt each one will make you a millionaire by itself (unless you invest a substantial sum of money). Yet if your portfolio can beat the market by just a few percentage points each year, that would dramatically accelerate your timeline toward becoming a millionaire, and I think buying these three long-shot AI stocks gives you opportunities to do just that.
