Better Quantum Stock: Rigetti Computing vs. Quantum Computing

Rigetti Computing (NASDAQ: RGTI) and Quantum Computing (NASDAQ: QUBT) represent two different ways to invest in the expanding quantum computing market. Rigetti is an established producer of quantum chips, systems, and cloud software solutions. Quantum Computing, also known as QCi, develops experimental -- but potentially disruptive -- chips.

Over the past 12 months, Rigetti's stock rallied nearly 60% but QCi's stock rose just 3%. Let's see why the former outperformed the latter, and if it remains the better quantum play.

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The differences between Rigetti and QCi

Quantum computers can store zeros and ones simultaneously in qubits, while classical computers still store them separately in binary bits. That difference enables quantum computers to consume more data and process specific tasks much faster than classical computers. Still, they're also bigger, pricier, more power-hungry, and more prone to errors.

That's why they're still mainly used for niche experiments at universities and government agencies. However, companies like Rigetti and QCi are addressing those weaknesses with new technologies, more powerful systems, and more accessible computing platforms.

Rigetti, like many of the older quantum computing system makers, accelerates electrons through superconducting loops to achieve a quantum state. These systems are easy to manufacture and scale, but they must be cryogenically refrigerated -- which makes them expensive to operate and maintain. They also have lower coherence fidelity (how long data remains in a quantum state) than newer technologies. However, they have higher gate fidelity (the accuracy with which their operations are performed) than other systems.

QCi develops photonic chips, which process data by beaming light through chips, fibers, and optical circuits. These chips can be easily manufactured in conventional chip fabs, operate at room temperature, and exhibit higher coherence fidelity than electron-driven systems. However, they're tricky to scale and expensive to manufacture in small quantities, and they have lower gate fidelity than electron-driven systems in operations that require more than a single gate.

Which company is growing faster?

Rigetti is a "full stack" quantum computing company that manufactures its own modular and non-modular quantum processing units (QPUs), installs them in its own quantum systems, and hosts a cloud-based quantum-computing-as-a-service platform called Forest. In other words, it's a "one-stop shop" for companies that want to invest in quantum systems.

Rigetti sells two completed systems: Ankaa-3, an 84-qubit system that runs on a single non-modular chip; and Cepheus-1-36Q, a 36-qubit system that links four modular 9-qubit chips. It plans to deploy its next 108-qubit Cepheus system and a 150+ qubit system later this year, followed by a 1,000+ qubit system by the end of 2027.

Rigetti's revenue declined in 2023, 2024, and 2025 as it struggled with uneven government contracts and the expiration of its contract with the U.S. National Quantum Initiative (NQI). However, analysts expect its revenue to grow more than sixfold from $7.6 million in 2025 to $45.4 million in 2027 as it rolls out its new systems and gains new contracts. Yet, with a market capitalization of $7.3 billion, Rigetti's stock is already richly valued at 160 times its projected 2027 sales. It's also expected to stay unprofitable for the foreseeable future.

QCi's technology sounds promising, but it only began delivering its first chips last year. Most of its revenue still comes from professional services contracts rather than chip sales, but it's gradually generating revenue from its cloud-based Dirac-3 quantum platform.

Analysts expect QCi to only generate $0.8 million in revenue this year. However, they expect its revenue to surge to $15 million in 2027 as it ramps up its chip production and challenges older electron-driven systems. That outlook seems promising, but QCi will also remain deeply unprofitable as it tries to challenge established quantum players like Rigetti. With a market cap of $2.5 billion, QCi looks even pricier than Rigetti at 166 times its 2027 sales.

The better buy: Rigetti Computing

Rigetti and QCi are both highly speculative stocks. But if I had to choose one over the other, I'd stick with Rigetti because it's expanding a proven technology and has a more precise roadmap for the future. QCi's photonic chips are potentially disruptive, but it needs to overcome some major manufacturing hurdles before it can challenge the established electron-driven leaders.

Leo Sun has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.