Quantum computing stocks: 10 biggest listed players by market value

Ranked by market value at the October 30, 2026 close, the ten biggest listed companies with quantum computing exposure are Nvidia, Microsoft, Alphabet, IBM, IonQ, Quantinuum, D-Wave, Rigetti, IQM and Quantum Computing Inc. The four largest are diversified technology groups, not quantum specialists. The six quantum-only companies are much smaller, and so is their revenue.

This ranking uses one measure only: market value on October 30, 2026. It is not a forecast of share prices.

Key takeaways

• Nvidia tops the list by market value at about $4.94 trillion.
• The six quantum-only companies are far smaller: IonQ is about $12.90 billion.
• Their revenue is small too: Quantinuum guides to $28 million to $32 million for 2026.
• Third-quarter results for the quantum-only names land between November 5 and November 10.
• Losses are heavy: Rigetti lost $52.6 million in the second quarter of 2026.

The ranking at a glance

Three labels run through this article. Pure play means quantum is the heart of the business. Strategic means a diversified technology group with its own quantum program. Enabling means supplying the computing platforms the sector runs on.

IBM and IonQ trade on the New York Stock Exchange. IBM also trades on NYSE Texas. The other eight trade on Nasdaq, a US stock exchange.

The 10 biggest quantum computing stocks, ranked by market value

1. Nvidia: about $4.94 trillion

Nvidia is the number one on this measure, and it does not sell its own quantum processors as its core business. It supplies quantum-classical computing platforms and infrastructure instead. So the quantum link here is the tools layer, not the machines.

2. Microsoft: about $3.88 trillion

Azure Quantum, Microsoft's cloud service, lists IonQ, Pasqal, Quantinuum and Rigetti as hardware providers, with Quantum Circuits coming soon in private preview. Microsoft says its quantum program has reached the Majorana 2 chip. It expects a scalable quantum computer by 2029. Those chips are with DARPA, a US defense research agency, for independent testing.

3. Alphabet: about $3.44 trillion

On October 15, 2026, Google Quantum AI announced that its Willow processor cut errors 40-fold using magic-state cultivation. This is a method for preparing quantum states. It reached 99.99% logical fidelity. This measures whether the resulting quantum state is correct. The result was published in the journal Science. For what actually moves the share price, see our guide to Google stock.

4. IBM: about $243.66 billion

IBM says it has signed more than $1.1 billion in quantum-program client contracts since 2017, and that more than 340 network organizations use its systems. On October 27, 2026, it connected two Nighthawk processors with meter-scale couplers at 99% average quantum-state-transfer fidelity, and it still targets its Starling machine for 2029. IBM's earnings materials do not state quantum revenue separately.

5. IonQ: about $12.90 billion

IonQ reported $80.1 million of revenue in the second quarter, but its reported revenue covers satellite data as well as quantum computing. Its second-quarter net loss under standard US accounting rules was $1,867.7 million. Full-year 2026 guidance is $450 million to $460 million for the combined company, including SkyWater from July 31. On October 14, 2026, IonQ priced a $2.0 billion equity offering of shares and warrants. On July 31, 2026, IonQ completed its SkyWater acquisition, a cash-and-stock deal valued at about $1.8 billion.

6. Quantinuum: about $8.85 billion

Quantinuum closed its Nasdaq initial public offering on June 5, 2026. This was its first public sale of shares. It sold 28 million shares at $60 each for $1.68 billion in gross proceeds. It guides to revenue of $28 million to $32 million for 2026. Cash and cash equivalents stood at $2.107 billion on June 30, 2026.

7. D-Wave: about $3.97 billion

D-Wave builds annealing machines. They are designed for tasks such as scheduling and routing. First-half 2026 bookings were $35.5 million, including a $20 million system sale whose revenue was to be recognised later, while second-quarter bookings were $2.1 million. It reported revenue from more than 100 customers in the first half, more than half of them commercial enterprises.

8. Rigetti: about $3.75 billion

Rigetti held $27.8 million in cash plus $513.5 million in investments on June 30, 2026, and used $32.0 million of operating cash in the first half. It disclosed an $8.4 million order to deliver a 108-qubit system to India's C-DAC. A qubit is the basic unit used in quantum computing. On September 8, 2026, Rigetti signed a definitive agreement for up to $100 million in Commerce funding, including a minority government equity stake.

9. IQM: about $1.64 billion

IQM is a Finnish company that completed a merger with a company already listed on the stock market on July 1, 2026, raising about €209.5 million in gross proceeds. Its US depositary shares began trading on Nasdaq on July 2, and its ordinary shares on Nasdaq Helsinki on July 3. Full-year 2026 revenue guidance is €42 million to €47 million. For more names from the region, see our ranking of the biggest European tech companies.

10. Quantum Computing Inc.: about $1.49 billion

QCi reported first-half 2026 revenue of $9.242 million. It held $189.15 million in cash and about $1.3 billion in cash, equivalents and investments on June 30, 2026. Its light-based NeuraWave platform was ready for deployment in the second quarter. It was covered by an agreement for up to multiple dozens of systems with potential value above $10 million, subject to milestones.

Pure plays versus big tech: what you actually own

With a pure play, quantum is the whole story. Quantinuum's 2026 revenue guidance of $28 million to $32 million sits against a market value of about $8.85 billion on October 30. Results arrive on a short clock too, with third-quarter numbers due from November 5 to November 10, 2026.

With the four strategic and enabling names, quantum is one program inside a diversified technology business. Alphabet booked $127.577 billion of revenue in the third quarter of 2026, and IBM does not break out quantum at all. On October 26, 2026, Intel announced a deal to acquire quantum-software company Classiq, with closing expected in the first half of 2027 and no price disclosed.

Risks

• Losses are large next to sales. D-Wave reported $3.1 million of second-quarter revenue and a $48.0 million net loss.
• Equity offerings can leave each existing share owning less of the business. IonQ priced a $2.0 billion equity offering in October 2026.
• Customers can be concentrated. Two unnamed Rigetti customers were 64% and 16% of its second-quarter revenue.
• Roadmaps are dates, not results. IBM targets Starling for 2029 and Microsoft expects a scalable machine by 2029.
• Big contracts are often conditional. IonQ's DARPA Stage C agreement, announced on October 7, 2026, has a potential value of up to $300 million rather than a completed award.

This article is for information only and is not investment advice.

Frequently asked questions

Which other quantum companies are listed?

Pasqal completed its merger on August 27, 2026. Its shares were expected to start trading on Nasdaq as PSQL the next day.

What is the difference between annealing and gate-based machines?

Annealing systems are built for optimisation problems, such as planning a delivery route or a shift roster. Gate-based machines aim at a wider range of computing tasks. D-Wave sells annealing machines and also has a gate-model roadmap. A physical qubit is a hardware unit. Its roadmap targeted a 17-physical-qubit system in 2026, 49 in 2027 and 181 in 2028.

How do customers actually get access?

They can get access through cloud services and paid plans. Azure Quantum lists IonQ, Pasqal, Quantinuum and Rigetti as hardware providers. IBM offers paid Pay-As-You-Go, Flex, Premium and On-Prem plans, and says the UK National Quantum Computing Centre's agreement gives researchers access to its Premium Plan.

Are these companies buying each other?

Yes. On October 12, 2026, IonQ announced a definitive agreement to acquire Elisity. The deal would be paid for with IonQ shares and was valued at up to $1.3 billion, subject to regulatory approval and other closing conditions.

How much comes from governments?

At Rigetti, U.S. government entities accounted for 48.0% of 2025 revenue. Rigetti reported $7.1 million of revenue for 2025 and a $216.2 million net loss, with US government entities accounting for 48.0% of that revenue.

Sources

• Google Quantum AI: Magic state cultivation on a superconducting quantum processor (October 15, 2026)
• IBM: IBM commits more than $10 billion to quantum computing (June 2, 2026)
• IonQ Investor Relations: IonQ announces pricing of $2.0 billion equity offering (October 14, 2026)
• Quantinuum: Quantinuum announces closing of upsized initial public offering (June 5, 2026)
• U.S. Securities and Exchange Commission: D-Wave Quantum Q2 2026 results exhibit (August 6, 2026)
• Rigetti: Rigetti signs definitive agreement for up to $100 million in U.S. government funding (September 8, 2026)
• U.S. Securities and Exchange Commission: IQM listing announcement exhibit (July 2026)
• U.S. Securities and Exchange Commission: Quantum Computing Inc. Q2 2026 results exhibit

Cover photo by Brian Kostiuk on Unsplash.