Shares of leading firms nose-dive after Nvidia’s Jensen Huang suggests a generational wait for fully functional quantum tech. We’ve been told that the future is now, but it seems it’s not quite here yet—at least not for quantum computing.

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.

The quantum computing rally came to an abrupt end on Wednesday following comments from Nvidia CEO Jensen Huang. During a question-and-answer session with analysts, Huang put forth a more pessimistic view of the quantum computing timeline: