Memory Chip Giant Just Had Its Worst Day Ever

Oil prices jumped on Monday following a weekend of attacks in the Middle East, while slumping AI stocks weighed on stock markets. Micron Technology and Nvidia helped lead the way lower after SK Hynix shares in Seoul fell to their largest loss ever.

• The S&P 500 fell 60.05 points, or 0.8%, to 7,515.34.
• The Dow Jones Industrial Average fell 138.37 points, or 0.3%, to 52,498.64.
• The Nasdaq composite fell 408.43 points, or 1.6%, to 25,873.18.

Brent crude's price climbed nearly 10% Monday after the United States and Iran each said the Strait of Hormuz is under its control, the AP reports. Oil prices are still below their wartime peak, but the sharp gains sent Treasury yields higher in the bond market on worries about inflation.

The gains for oil prices accelerated immediately after President Trump said he's reinstating a blockade to prevent tankers carrying Iranian oil from using the strait. He also called for 20% payments on all cargo shipped through it to reimburse the United States for providing protection in the area. Brent's price, though, remains well below its wartime peak of nearly $120 per barrel for its most actively traded contract.

On Wall Street, Micron sank 4.4%, eating into what had been a stellar rise of 243.1% for the year so far. Real profits are behind the rise because the AI rush has created surging demand for computer memory and other computing building blocks. But worries are rising that stock prices have shot too high and that the demand may not be sustainable if AI doesn't deliver as much profit and productivity as expected. Nvidia fell 3.5% and was the single heaviest weight on the S&P 500.

• The day's losses began in Asia, where South Korea's Kospi index dropped 8.9%. That included a 15.4% plunge for SK Hynix's stock in Seoul, the worst since it began trading in 1997. The South Korean tech giant just launched shares of its stock trading in the United States on Friday, raising roughly $26.5 billion. Those shares jumped 13.1% in their first day of trading, but they fell 9.3% Monday.

Much of Wall Street's attention this week will be on profit reports from companies saying how much they earned during the spring. On Tuesday alone, Bank of America, Citigroup, JPMorgan Chase, Goldman Sachs, and Wells Fargo are all releasing their latest quarterly results. Analysts are forecasting that companies in the S&P 500 index will deliver overall growth of 23.6% from a year earlier, according to FactSet. If they're right, it would be the second straight quarter of growth better than 20%.