90% of the comments in this thread make it clear that knowing about technology does not in any way qualify someone to think correctly about markets and equity valuations.
The crash is absolutely rational; the cascading effect highlights the missing moat for companies like OpenAI. Without a moat, no investor will provide these companies with the billions that fueled most of the demand. This demand was essential for NVIDIA to squeeze such companies with incredible profit margins. NVIDIA was overvalued before, and this correction is entirely justified. The larger impact of DeepSeek is mo…
1) AI stuff isn't really worth trillions, in which case Nvidia is overvalued.
2) AI stuff is really worth trillions, in which case there will be no moat, because you can cross any moat for that amount of money, e.g. you could recreate CUDA from scratch for far less than a trillion dollars and in fact Nvidia didn't spend anywhere near that much to create it to begin with. Someone else, or many someones, will spend the money to cross the moat and get their share.
So Nvidia is overvalued on the fundamentals. But is it overvalued on the hype cycle? Lots of people riding the bubble because number goes up until it doesn't, and you can lose money (opportunity cost) by selling too early just like you can lose money by selling too late.
Then events like this make some people skittish that they're going to sell too late, and number doesn't go up that day.