Quantum computing stocks faced a sharp decline following remarks from Jensen Huang, CEO of $NVIDIA (NVDA.US)$. During Nvidia's analyst day, Huang expressed optimism about quantum computing's future but warned that practical applications might be 15 to 30 years away.

What Happened: Huang highlighted that while quantum computing is effective for small data and big compute tasks, it struggles with large data due to its microwave-based communication. He emphasized the necessity of classical computers for error correction, positioning Nvidia as a significant player in the classical-quantum computing space. Nvidia collaborates with nearly every quantum computing company worldwide, extending their CUDA platform to quantum applications.

"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.

"If you picked 20, I think a whole bunch of us would believe it."

Following Huang's comments, quantum computing stocks saw a notable drop in overnight trading in Robinhood on Wednesday. $IonQ Inc (IONQ.US)$ fell by 10.75%, $Quantum Computing (QUBT.US)$  declined by 12.86%, and $D-Wave Quantum (QBTS.US)$ and $Rigetti Computing (RGTI.US)$  experienced decreases of 14.14% and 13%, respectively. The market's reaction reflects investor concerns over the extended timeline for quantum computing advancements.

Why It Matters: The recent downturn in quantum computing stocks underscores the challenges and uncertainties facing the sector. As highlighted by Jim Cramer, the long development timelines and current market valuations raise concerns for investors. Despite the U.S. quantum computing market's projected growth from $138.2 million in 2022 to $1.2 billion by 2030, the path to practical applications remains lengthy.

Quantum computing is often compared to artificial intelligence in terms of its transformative potential. Experts predict it will drive breakthroughs in fields like cryptography, drug discovery, and optimization. However, the technology's reliance on qubits, which can represent multiple states simultaneously, means it still faces significant hurdles before it can match the speed and efficiency of classical computers.