Shares in memory chip companies slumped across U.S. markets Monday, in a further sign of investor concerns over how much road is left for the AI stock market boom.
SK Hynix’s American depository shares were down 8.9% by midday Monday, just days after its blockbuster stock market debut last week, the largest ever U.S. IPO by a foreign company.
The chip giant was also the biggest faller in South Korea, plunging a record 15%, while tech giant Samsung also dropped 10.5%. The two firms dominate the country’s Kospi index, and the falls were so steep that they triggered a temporary stop in trading.
Now, the selloff has carried over to the Nasdaq, where SK Hynix has its new secondary listing. Fellow memory storage company Micron Technology was down 4.8%; Sandisk fell 10.7%; and Western Digital was down 5.9% by midday Monday.
Investors piled into SK Hynix’s U.S. debut Friday, keen to get a piece of another company that has benefitted hugely from the AI infrastructure boom. The Korean group is the global leader in high-bandwidth memory, the type needed for the most powerful AI servers. The IPO raised $26.5 billion and was more than seven times oversubscribed.
Revenue and profit have surged recently, amid an ongoing memory chip shortage driven by AI companies’ vast demand for data center buildouts. Operating profit jumped 405% year-over-year in the first quarter of 2026, while revenue surged 198%, SK Hynix reported in April.
But analysts are concerned about how fast shares have gone into reverse. Semiconductor stocks have been especially volatile in recent weeks, following a red-hot period earlier this year when many of them rallied dramatically.
“It was always going to be a volatile ride after the company’s American depositary receipts began trading at such a heady valuation,” wrote Susannah Streeter, chief market strategist at Wealth Club, in a note. “While companies right now can’t get enough of SK Hynix’s products, there are concerns that a lot of this demand has been front-loaded and will ultimately prove cyclical.”
SK Hynix appears to have been hurt by a report from Korea Investment & Securities, which projected its operating profit for the latest quarter may trail analyst forecasts by 8%. The brokerage pointed to its reliance on HBM as a share of revenue, saying prices are not rising as fast in that area as for conventional chips, reported Bloomberg.
Other analysts suggested the volatility was to do with what the company’s fair value should be.
“Everybody’s really confused about what’s going to happen to the memory demand and where the fair price is,” Daniel Yoo, global strategist at Yuanta Securities, told CNBC. “It’s all about how much demand is there versus how much supply is going to come in . . . [and] what kind of multiple you will be getting.”