Shares of quantum computing company Rigetti Computing (RGTI) plummeted 8.43% in pre-market trading on Friday after Nvidia CEO Jensen Huang cast doubts on the near-term prospects of "very useful" quantum computers, deflating recent hype and speculation around the nascent technology.

Rigetti and other quantum computing stocks like IonQ (IONQ), D-Wave Quantum (QBTS), and Quantum Computing Inc. (QUBT) had surged in recent months as investors became increasingly optimistic about the potential of quantum computing to revolutionize various industries. However, Huang's comments at Nvidia's analyst day suggested that commercially viable quantum computers could still be 15 to 30 years 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 told analysts, adding that a 20-year timeline would be more realistic for many to believe.