IonQ Shares Jump 11% After Quantum Error Correction Decoder Validation

IonQ (IONQ) shares rose more than 11% on Wednesday, September 23, 2026, after the quantum computing company announced what it called the industry's first end-to-end real-time quantum error correction decoder, validated across hundreds of logical qubits. The decoder runs on a single off-the-shelf CPU, allowing error correction to operate continuously without stalling quantum hardware, IonQ said. Testing covered up to 408 logical qubits across 88 memory blocks and more than 31.5 million quantum operations. Under standard noise conditions, the decoder added as little as 0.02% stretch time, according to the company. IonQ said the results, published on arXiv, support its roadmap to scale beyond 256 physical qubits toward systems controlling thousands of qubits via its Walking Cat architecture. Peer quantum names Rigetti Computing, D-Wave and Quantum Computing each gained more than 4% premarket.