Quantum computing stocks sank on Wednesday, pausing a year-long rally, after Nvidia CEO Jensen Huang said the technology's practical use was likely two decades away. The long wait outlined by Huang for "very useful quantum computers" throws cold water on a sector that was already expected to spend millions more on the technology,

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The shares of IonQ Inc. and other companies linked to quantum computing tumbled in extended trading on Tuesday after Nvidia Corp. Chief Executive Officer Jensen Huang said “very useful” quantum computers are likely decades away.