The quantum computing space is a great place to look for stocks with millionaire-maker potential. This nascent technology has the capability to supplement some of the incredible technology being developed in the classical computing realm in remarkable ways. Hybrid systems that link quantum computers with traditional machines could solve problems that are far beyond the capacities of even the most powerful classical supercomputers.
While quantum computing may not be a relevant industry right now -- as the technology is simply not mature enough for commercial applications -- it may be by 2030. By 2035, many tech sector gurus expect it to be in fairly widespread use. In that light, investing in emerging quantum computing stocks now may be a bit risky, but I think if you pick the right ones, they could pay off in a big way.
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How big is the quantum computing market?
According to a forecast published by McKinsey & Company, the quantum computing market could be worth up to about $72 billion annually by 2035. That's the high point of the consultancy's projection -- it extends down to $28 billion on the low end. Still, that's a huge market that essentially doesn't exist yet, and if IonQ (IONQ 0.80%) or D-Wave Quantum (QBTS 1.27%) can capture a large chunk of that, they should prove highly successful investments.
But that prediction is for a decade from now, and the opportunity cost for investors will be high if these two don't pan out.
Unusual approaches to quantum computing
Every quantum computer is built around qubits -- the fundamental units by which they store and manipulate data. But there are a host of different technological methods for creating those qubits, and there are players in the space exploring all of them. The most popular is to create superconducting qubits, which involves cooling circuits to nearly absolute zero -- a temperature that allows them to behave according to quantum mechanical principles. This technique is employed by several big-name tech companies, as well as some quantum computing start-ups.
But neither IonQ nor D-Wave uses this method.
IonQ utilizes a trapped-ion approach -- isolating and supercooling individual atoms to create qubits -- while D-Wave uses an even more unusual technique called quantum annealing. IonQ's trapped-ion approach has advantages in terms of high fidelity, which is important. The primary challenge that all quantum computing systems face today is that they are not remotely accurate enough to compete with traditional computing.
IonQ has achieved the world's best 2-qubit gate fidelity score -- a commonly used metric to assess accuracy among quantum computers. Most other companies are struggling to cross the 99.9% threshold, while IonQ achieved 99.99% fidelity in October 2025. Time will tell if IonQ can maintain its lead, but if it does, it has a strong chance of panning out. But while 1 error in 10,000 calculations is better than its peers have achieved, traditional computers' error rates are around 1 in 1 quintillion calculations. (A quintillion? That's 1 billion times 1 billion.) So quantum computing has a long way to go.
NYSE: IONQ
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IonQ and most of its peers are trying to make general-purpose quantum computers that are suitable for handling a broad range of extremely complex problems. D-Wave Quantum is taking a more specialized approach. Its quantum annealing systems are specifically well suited for optimization problems -- its technology rapidly finds some of the lowest energy points in complex systems, which correspond to optimal or nearly optimal solutions to the computations they are handling.
There are plenty of other types of problems that researchers hope to address using quantum computers, but some of the most promising use cases are for optimization problems -- among them, logistics networks, weather modeling, artificial intelligence (AI) training and inference, and statistics. If D-Wave can carve out a niche for itself in this space, then it could be one of the top quantum computing investments over the long haul.
NYSE: QBTS
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But could either of these stocks make you a millionaire? It's tough to say. Let's hypothetically project that one company can capture the entire $72 billion annual market opportunity by 2035. That would be a near-impossible task, but it shows the maximum upside for each stock. If such a company could generate a 50% profit margin from those sales (similar to the best computing hardware companies today), that would translate into $36 billion in profits. If that company were valued at 50 times earnings, it would have a market cap of $1.8 trillion.
IonQ and D-Wave have market caps of $11.8 billion and $6.7 billion, respectively. So, their maximum potential 10-year returns range from about 152 times to 269 times if each stock conquers that market opportunity.
Those would be huge gains, but they could only happen in the most ideal situation, which is highly unlikely to transpire. I think each of these stocks could be worth an investment, but investors must understand the risks associated with them. Each has huge upside potential, but if their technologies don't pan out or if rivals outpace them, the stocks could go to $0.
But their upsides are nearly unlimited, a proposition that could appeal to risk-tolerant investors. If you want to open a small position (say, no more than 1% of the value of your portfolio), then each of these stocks could be a great lottery ticket to stash away.
