Shares in Quantum Computing Inc., D-Wave Quantum Inc. and Rigetti Computing Inc. dropped more than 30%, while IonQ fell about 29%. These stocks have soared in recent months amid excitement about the technology’s potential, which was heightened last month following a quantum computing breakthrough by Alphabet Inc.
The shares of IonQ Inc. and other companies linked to quantum computing tumbled on Wednesday, after Nvidia Corp. Chief Executive Officer Jensen Huang said that “very useful” quantum computers are likely decades away.
“If you kind of said 15 years for very useful quantum computers, that would probably be on the early side. If you said 30, it’s probably on the late side,” Huang said in a question-and-answer session during Nvidia’s analyst day. “If you picked 20, I think a whole bunch of us would believe it.”

