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.

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.