Quantum computing stocks got pummeled yesterday, with the four most prominent public quantum computing companiesIonQ, Rigetti Computing, Quantum Computing Inc., and D-Wave Quantum Inc.falling anywhere from over 9% to over 18%. The reason? A lot of it may have to do with AI chip giant Nvidia. Again.Stocks crash yesterday on Nvidia quantum newsYesterday was a bit of a bloodbath on the stock market for the four most prominent publicly traded quantum computing companies. Heres a breakdown of how they performed, according to data from Yahoo Finance:IonQ, Inc. (NYSE: IONQ): down 9.27% to $21.14 per shareRigetti Computing, Inc. (Nasdaq RGTI): down 9.24% to $8.99 per shareQuantum Computing Inc. (Nasdaq: QUBT): down 11.71% to $7.39 per shareD-Wave Quantum Inc. (NYSE: QBTS): down 18.02% to $8.69 per shareAll four of these quantum computing stocks tumbled on the day that AI chip giant Nvidia kicked off its two-day Quantum Day event. In a blog post from January 14 announcing Quantum Day, Nvidia said the event brings together leading experts for a comprehensive and balanced perspective on what businesses should expect from quantum computing in the coming decades mapping the path toward useful quantum applications.But thats not all that Nvidia did. Besides bringing quantum experts together, the AI behemoth also announced that it will be launching a new quantum computing research center in Boston.Called the NVIDIA Accelerated Quantum Research Center (NVAQC), the new research lab will help solve quantum computings most challenging problems, ranging from qubit noise to transforming experimental quantum processors into practical devices, the company said in a press release.The NVAQCs location in Boston means it will be near both Harvard University and the Massachusetts Institute of Technology (MIT).Quantum computing will augment AI supercomputers to tackle some of the worlds most important problems, from drug discovery to materials development, Nvidias CEO, Jensen Huang, said. Working with the wider quantum research community to advance CUDA-quantum hybrid computing, the NVIDIA Accelerated Quantum Research Center is where breakthroughs will be made to create large-scale, useful, accelerated quantum supercomputers.Its not the first time stocks reacted to Nvidias CEONvidias announcement of the NVIDIA Accelerated Quantum Research Center apparently sent shivers down the spines of many quantum computing investors, with shares of QBTS, RGTI, IONQ, and QUBT all crashing.Before Nvidias announcement yesterday, IonQ, Rigetti, D-Wave, and Quantum Computing Inc. were the leaders in the nascent field of quantum computing. And while they still are right now (Nvidias quantum research lab hasnt been built yet), the fear is that Nvidia could use its deep pockets to quickly buy its way into a leadership spot in the field. With its $2.9 trillion market cap, the company can easily afford to throw billions of research dollars into quantum computing.As noted by the Motley Fool, the location of the NVIDIA Accelerated Quantum Research Center in Boston will also allow Nvidia to more easily tap into top quantum talent from Harvard and MITtalent that may have otherwise gone to IonQ, Rigetti, D-Wave, and Quantum Computing Inc.Nvidias announcement is a massive about-face from the company in regard to how it views quantum computing. Its also the second time that Nvidia has caused quantum stocks to crash this year. Back in January, shares in prominent quantum computing companies fell after Huang said that practical use of quantum computing was decades away.Those comments were something quantum computing company CEOs like D-Waves Alan Baratz took issue with. Its an egregious error on Mr. Huangs part, Bartaz told Fast Company at the time. Were not decades away from commercial quantum computers. They exist. There are companies that are using our quantum computer today.According to Investors Business Daily, Huang reportedly got the idea for Nvidias Quantum Day event after the blowback to his comments, inviting quantum computing executives to the event to explain why he was incorrect about quantum computing.Quantum Computing Inc. Q4 results may also play a roleBut it wasnt just the Nvidia news that may have contributed to yesterdays quantum sell-off. Also yesterday, Quantum Computing Inc. (QCi) announced its Q4 2024 results.Those results were not good news for the company. As The QuantumInsider noted, QCI announced it had $62,000 in total revenue for the quarterdown from $75,000 in the quarter a year before. Wall Street consensus had expected around $400,000 in revenue. The company also had a net loss of $51.2 million versus a net loss of $6.8 million in the same quarter a year earlier.Announcing its Q4 results, Quantum Computing Inc.s CEO, William McGann, said QCi made meaningful progress in the fourth quarter strengthening our financial position to support the continued advancement of our quantum solutions and foundry services. With a significantly bolstered balance sheet, we are well-positioned to scale operations and accelerate commercialization efforts.He also noted that the company is still on track to launch its foundry that will produce quantum photonic chips in early 2025.Still, that news was not enough to mitigate investor disappointment over its Q4 results. The stock fell over 11% yesterday and is down over 10% in premarket trading today.Quantum stocks sometimes rise and fall in unison, so when one company posts bad results, it can tend to drag the stock prices of other quantum computing companies lower, too.How quantum computing stocks are trading todayAfter the announcements above, including Huang announcing Nvidias intention to launch the NVIDIA Accelerated Quantum Research Center, quantum computing stocks tankedand they arent doing much better today. As of the time of this writing, the four most prominent quantum computing stock prices are all down in premarket trading:IONQ: down 1.09%RGTI: down 3.00%QUBT: down 10.4%QBTS: down 4.83%Since the start of 2025, three of those four quantum computing stocks have been hit hard. As of yesterdays close IONQ had lost more than 49% of its value, RGTI has lost 41%, and QUBT has lost 55%. Only QBTS has seen a modest gain of 3.45% for the year to date, though that gain has been wiped out in premarket trading this morning as of the time of this writing.However, despite these quantum computing stocks being in the red for 2025, over the past 12 months, all have shown impressive returns, with IONQ up over 120%, RGTI over 425%, QUBT over 495%, and QBTS over 323% as of yesterdays close.As for Nvidia, investors seem not to care much about its quantum announcement. Yesterday, NVDA stock closed up just 0.86%, and today, the stock is currently down a paltry 0.76% in premarket trading. Since 2025 began, NVDA stock has been down almost 12%, while it has been up over 31% over the past 12 months, as of yesterdays close.This post has been updated with additional context on QCis earnings.