IonQ (IONQ) surged more than 12% in after-hours trading on Tuesday, climbing to approximately $45.74 after closing at $40.74, following the company’s announcement of what it calls the industry’s first end-to-end real-time quantum error-correction decoder running on a single standard CPU.
The company said its dual-decoder architecture handled simulated benchmark workloads of up to 408 logical qubits across 88 memory blocks and magic factories, processing more than 31.5 million individual quantum operations. Under standard operating noise, the decoder added as little as 0.02% of stretch time, meaning the classical error-correction process introduced almost no additional delay to the simulated computation.
IonQ research lead Nicolas Delfosse described the validation as an important milestone, noting that running the decoder on a single CPU offers a possible path toward commercial-scale fault-tolerant systems. The result supports the company’s proprietary Walking Cat architecture as it plans to move beyond 256 physical qubits toward platforms controlling thousands of qubits.
However, the achievement carries a key caveat: the tests used simulated benchmark circuits and simulated noise, not a physical quantum computer with 408 logical qubits. A fully fault-tolerant machine still requires reliable physical hardware, error-correction codes, control electronics, and classical decoding at scale.
Wedbush reiterated an Outperform rating and a $75 price target on IonQ shares. In Wednesday’s premarket session, IonQ remained up about 11%-12%, leading market movers alongside Worthington Enterprises, Super Micro, Dell, and Six Flags, while Sandisk, AMD, Broadcom, and Qualcomm pulled back as investors took profits.
