Shares in major quantum computing firms dropped on Thursday after an announcement from Nvidia chief Jensen Huang. It’s not the first time. Quantum computing stocks got pummeled yesterday, with the four most prominent public quantum computing companies—IonQ,

IonQ's executive chairman said it's a bad idea to bet against Nvidia. IonQ stock rose a day after Nvidia's Quantum Day.

Investing is sometimes about weighing the potential reward versus the risks involved. Sure, IonQ could become a powerhouse in quantum computing. The issue is that the stock is already valued as if it's a given when it's not. If things don't work out as investors hope, the stock has an immense downside from its current price.