Top Quantum Computing Stocks

The companies building the quantum future — and how UK investors can access them

Author: Arlo | Date: 2026-08-16

The Quantum Computing Landscape

Quantum computing stocks fall into two categories: diversified tech giants where quantum is one division among many, and pure-play companies whose entire business is quantum. Each carries different risk and reward profiles.

The Diversified Giants

IBM (NYSE: IBM)

IBM has been the public face of quantum computing for over a decade. Its IBM Quantum platform offers cloud-based access to real quantum hardware, and the company has deployed systems with over 1,000 qubits. IBM's roadmap targets fault-tolerant quantum computing by 2029.

For investors, IBM offers quantum exposure alongside established businesses in mainframe computing, consulting and AI. The dividend yield (typically 2-3%) provides some downside protection. IBM is listed on the NYSE and is available through most UK brokers.

Alphabet / Google (NASDAQ: GOOGL)

Google claimed "quantum supremacy" in 2019 when its Sycamore processor solved a problem faster than the world's best supercomputer. Google's quantum division continues to advance, with significant progress in error correction announced in 2024-2025.

Of course, Alphabet is primarily a search and advertising company. Quantum is a tiny fraction of its business. But for investors who want exposure to quantum without taking on pure-play risk, Alphabet is one of the safest options.

Microsoft (NASDAQ: MSFT)

Microsoft is pursuing a unique topological qubit approach, theoretically more stable than other designs. The company also offers Azure Quantum, a cloud platform that provides access to multiple quantum hardware providers.

Like Alphabet, Microsoft is primarily a software and cloud company. Quantum is a long-term bet within its broader AI and cloud strategy. Available through all major UK brokers.

The Pure-Play Stocks

IonQ (NYSE: IONQ)

IonQ is the first pure-play quantum computing company to go public. It uses trapped-ion technology, which offers high-fidelity qubits with long coherence times. IonQ has partnerships with Amazon Braket, Microsoft Azure Quantum and others.

IonQ's revenue is still small — under $50 million annually — and the company is not yet profitable. The stock is volatile and has experienced significant dilution. However, it's the most liquid pure-play quantum stock available to UK investors.

Rigetti Computing (NASDAQ: RGTI)

Rigetti builds superconducting quantum processors and operates its own quantum foundry in California. The company went public via SPAC in 2022. Like IonQ, Rigetti is pre-profit with modest revenues, but its technology is well-regarded and it has secured government contracts.

D-Wave Quantum (NYSE: QBTS)

D-Wave is the oldest commercial quantum computing company, founded in 1999. It uses quantum annealing — a different approach that's not a universal quantum computer but is specialised for optimisation problems. D-Wave's systems are used by companies including Volkswagen, Mastercard and Los Alamos National Laboratory.

D-Wave has real customers and revenue (though still small), making it arguably the closest to commercial viability among the pure-plays. However, the annealing approach has limitations compared to gate-based quantum computing.

Quantinuum (Honeywell)

Quantinuum was formed by the merger of Honeywell Quantum Solutions and Cambridge Quantum in 2021. It's a private company, but Honeywell (NASDAQ: HON) retains a majority stake — so buying Honeywell stock provides indirect exposure.

Quantinuum uses trapped-ion technology and has strong UK operations, particularly in Cambridge. It's widely considered one of the technical leaders, especially in quantum cryptography and software. An IPO is possible in the coming years.

How to Access These Stocks from the UK

All the stocks above are listed on US exchanges (NYSE or NASDAQ). UK investors can access them through most major brokers:

Holding US stocks in a UK Stocks and Shares ISA or SIPP is tax-efficient, though US dividend withholding tax (15% under the UK-US tax treaty) still applies. See our guide on buying quantum stocks in the UK for full details.

Which Approach Is Right for You?

The Bottom Line

The quantum computing investment landscape offers options for every risk appetite. The diversified giants provide safe, indirect exposure; the pure-plays offer high-risk, high-reward potential. For most UK investors, a mix of both — perhaps via a quantum ETF — is the sensible approach.

Next Steps

Nothing on this site is financial advice. All content is educational. Always do your own research and consult a qualified financial adviser before making investment decisions. Back to all guides.