IonQ Breaks Quantum Computing Record With 99.99% Fidelity

Oct. 21 IonQ Inc. IONQ shares are in focus on Tuesday after the Maryland-based quantum computing company said it had achieved a new industry milestone.

The firm reported that its systems reached a 99.99% two-qubit gate fidelity, a measure of how accurately quantum bits interact, marking the first time a commercial company has crossed the four-nines threshold. The result was detailed in two peer-reviewed papers and surpassed the previous benchmark held by Oxford Ionics, acquired by IonQ in a $1.07 billion deal completed last month.

Chief Executive Officer Niccolo de Masi described the development as an important step toward fault-tolerant quantum computing, which could reduce system complexity and speed up commercial applications.

IonQ said performance gains were supported by growing demand from enterprise and government clients for scalable quantum systems. The company also highlighted progress in integrating Oxford Ionics' trapped-ion technologies following the merger.

The stock has advanced roughly 39% so far in 2025 and more than tripled over the past 12 months, reflecting investor optimism about IonQ's technological progress and long-term growth potential.