Quantum computing stocks are tumbling after Nvidia CEO Jensen Huang warned that the technology is a long way off.

Rigetti Computing, IonQ, and other quantum stocks plunged after Nvidia CEO Jensen Huang told Wall Street analysts that “very useful quantum computers” are likely 20 years away.

IonQ (NASDAQ:IONQ) is arguably the leading stock in the quantum computing space. Prior to today, its stock was up nearly 500% over the last three months as it works to push quantum physics into computing to make massive,

Quantum computing stocks like IonQ, Rigetti Computing, D-Wave Quantum, and Quantum Computing were each down by more than a whopping 40% after Nvidia chief Jensen Huang’s comments that he did not expect quantum computers to be a reality any time soon.