Nvidia has current market cap equivalent to ~8 times ExxonMobil. If tomorrow ExxonMobil disappears from existence, you'd get half of the world paralysed. If Nvidia tomorrow gets replaced by a massive hole in the ground, you'd just shrug, go down the road a bit and buy AMD. Sure, they can't make cards as fast as Nvidia does, but they still work, the old cards won't suddenly stop working, and they don't even manufacture their own hardware.
The AI stocks nowadays are pumped up by pure hype, and it's inevitable that the market will recalibrate sooner or later
The AI stocks nowadays are pumped up by pure hype, and it's inevitable that the market will recalibrate sooner or later