Leading Quantum Computing Companies by Market Capitalization

Six pure-play quantum computing companies currently trade on U.S. exchanges: IonQ (IONQ), D-Wave (QBTS), Rigetti (RGTI), Quantum Computing Inc. (QUBT), Arqit Quantum (ARQQ), and Infleqtion (INFQ). Alongside them, several of the world’s largest tech companies — including IBM, Alphabet, Microsoft, and Honeywell — are investing heavily in quantum research and development.

While classical computers process information in bits, quantum computers use qubits, built with different physical technologies depending on the company:

• Trapped ions: IonQ, founded in 2015, was the first pure-play quantum company to go public. It uses ytterbium and barium ions and makes its systems available through all major public cloud services.
• Quantum annealing: D-Wave, founded in 1999 in British Columbia, is described as the world’s first commercial supplier of quantum computers. Its acquisition of Quantum Circuits Inc. made it the first dual-platform quantum company.
• Superconducting gate-model: Rigetti Computing, founded by an ex-IBM quantum scientist, is the only publicly traded company that designs, fabricates, and operates its own full-stack superconducting systems.
• Photonics: Quantum Computing Inc. (QCI), based in Leesburg, Virginia, specializes in photonic quantum computing following its acquisition of QPhoton.
• Quantum security: Arqit Quantum focuses on post-quantum cryptography and security software.

Among larger companies, IBM was the first to offer cloud-based quantum computing access, and its open-source Qiskit toolkit has become an industry standard for quantum programming. Google’s Quantum AI group, founded in 2012, achieved the first “quantum supremacy” claim. Honeywell operates in the space through Quantinuum, formed from the merger of Honeywell Quantum Solutions and Cambridge Quantum Computing.

Key commercial application areas include drug discovery, finance and portfolio optimization, energy grid optimization, and defense. Quantum computing also has implications for cybersecurity, with the capacity to both break and reinforce encryption methods. The pure-play quantum computing stocks are considered more speculative, as the technology remains in its early stages.

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The following table ranks the largest quantum computing companies by market capitalization, including both pure-play quantum firms and diversified technology companies with major quantum programs. All data — price, market cap — updates automatically to reflect current market conditions.