CoreWeave and Oracle have borrowed heavily to build more AI data-center capacity, spooking bond markets and sending debt-insurance prices soaring.

AI stocks soared Thursday after memory chip maker Micron reported far stronger-than-expected quarterly results, offering tech investors a glimmer of hope after weeks of disappointing performance for AI stocks.

Oracle's drop dragged other AI-related stocks lower, as well. Some of the worst performers on the Nasdaq 100 index included chipmakers such as Broadcom and Arm Holdings, which were both down around 5%. The Nasdaq Composite also slid more than 1.8%. The S&P 500 fell 1.2%.

One leading tech company, Oracle (NYSE: ORCL), recently posted earnings that appear to have sent some shockwaves throughout the AI world. Investors were taken aback by its latest results, and they could be a problem for AI stocks as a whole. Here's why.

Some prominent investors who have successful track records of calling other market declines have become vocal critics of the AI boom. Michael Burry and Jim Chanos are both shorting Nvidia stock, meaning they will make money if the price goes down further.

Fujikura Ltd.’s stock has surged about 1,400% over the last two years as new data centers globally have created an insatiable appetite for its cables. There’s only one problem — the company can’t keep up with demand.

Fortinet stock's forward P/E of 31 and EV-to-sales ratio of 8.7 are attractive prices to pay for a company growing sales at a double-digit pace. With more sales coming from software solutions, it should produce strong margin expansion, enabling it to grow the bottom line even faster.

Broadcom dropped 4.5%, Oracle fell 5.4% and CoreWeave sank 7.1%. Nvidia, the chip company that’s become Wall Street’s most influential stock because of its tremendous size, fell 3.8% and was the day’s heaviest weight on the S&P 500.