Nvidia's stock price swung wildly over a 3-day period, erasing $430 billion in market value as the stock plunged 13%. Nvidia's revenue and profits have skyrocketed. Its AI chips have been in high demand from major tech companies like Microsoft, Meta, Amazon, and Alphabet, who have collectively spent over $150 billion on capital expenditures. Some investors worry that demand may cool if companies don't see sufficient returns on their AI investments, which could lead to a "reckoning" for Nvidia's high stock valuation.