IonQ vs. Rigetti Computing: Which Quantum Computing Stock Will Outperform in 2026?

Quantum computing stocks gained a lot of attention in 2025 as the next big potential technological innovation after artificial intelligence (AI). Two of the most prominent pure-plays in the space are IonQ (NYSE: IONQ) and Rigetti Computing (NASDAQ: RGTI). While both stocks went on wild rides in 2025, it is Rigetti that is set to outperform in 2025 with a year-to-date gain of nearly 50% versus around 15% for IonQ, as of this writing.

Let's look at which stock is set to outperform in 2026.

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The case for IonQ

Quantum computing is very much in its early days, and revenue for these companies is relatively modest. As such, how they perform will mostly come down to how their technology progresses and the milestones they hit.

IonQ's potential advantage in the quantum computing race is its trapped-ion technology. Instead of using fabricated quantum bits, or qubits, like most companies in the space, IonQ's systems use actual ytterbium and barium atoms. Since every atom of an element is identical, they are more stable, which can lead to fewer errors, which is one of the biggest obstacles facing quantum computing. While these systems can initially be more expensive to build, they do have an advantage, as IonQ doesn't need to design new chips to make its systems more powerful; it can just add more ions.

At the same time, IonQ wants to take a page out of Nvidia's book and build an entire quantum computing ecosystem. While Nvidia is known for its powerful graphics processing units (GPUs), it is the company's CUDA software platform and networking portfolio that have made it the dominant company in AI infrastructure. In a similar vein, IonQ has gone out and made aggressive acquisitions in the space to pick up quantum sensing, interconnect, satellite, and semiconductor technology. It's also developed software to help further reduce errors. It will use this technology to make better systems, as well. For example, it is looking to move to a modular architecture, where it can link small ion traps with photonic interconnects, to make even bigger jumps in power.

The company has a massive war chest of cash on its balance sheet to continue to fund research and development and make more acquisitions. Meanwhile, it has seen strong growth, with its revenue soaring more than 200% in Q3 to nearly $40 million.

The case for Rigetti Computing

While IonQ has an accuracy advantage with its trapped-ion technology, Rigetti's superconducting qubit technology is faster. In fact, it is much faster, with reports that its technology can be 10,000 times faster. That could eventually become a big advantage.

Rigetti currently has a more than 100-qubit chiplet-based system with 99.5% fidelity (accuracy) and is looking to bump that up to an over 1,000-qubit system by 2027. While 99.5% fidelity seems high, it does trail IonQ's 99.99% accuracy, and for computers, both are still considered very error-prone. Computer scientists generally believe that quantum computing companies need to hit at least 99.9% fidelity before even considering implementing other error-reducing techniques. However, if Rigetti does make an error-reduction breakthrough, its speed advantage would help put it in the driver's seat.

Meanwhile, the company also has a partnership with Nvidia, where its system can be integrated into its NVQLink platform. It also has a three-year contract with the U.S. Air Force and has made some commercial sales for its Novera QP system.

The verdict

IonQ is in a stronger financial position and has achieved more sales. Meanwhile, the company's more accurate technology trumps Rigetti's speed advantage. As the old baseball saying goes, no one cares how fast you throw ball four.

Overall, I think IonQ is better positioned for the long run with its trapped-ion technology and ecosystem approach. Meanwhile, there are a few milestones it can hit in 2026 that could send its stock higher, including showing breakeven error correction (being more reliable than an actual atom) and demonstrating a multi-core quantum computer that uses photonic interconnects, which would help solve scaling issues. As such, I think it will be the quantum computing stock that outperforms in 2026.

Geoffrey Seiler has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends IonQ and Nvidia. The Motley Fool has a disclosure policy.