Micron Stock Falls 5% as South Korean Memory Giants Reverse Thursday’s Gains.

Micron shares are losing some of Thursday’s 16% post-earnings jump. The stock fell 5% in premarket trading Friday after SK Hynix dropped 8.4% and Samsung fell 5.3% in South Korea. These declines pulled the KOSPI index down as much as 8% before regulators stopped trading. The index later recovered somewhat, ending the day down 5.8%. Here’s what caused the reversal and why the issue is bigger than just one day.

The main concern has been growing quietly during the memory chip boom. This week, both Apple and Microsoft announced they are raising hardware prices because memory components have become more expensive. Apple increased MacBook and iPad prices by $100 to $300, and Microsoft is raising Xbox console prices for the same reason. Investors worry that higher prices for consumers could lower demand for devices that use a lot of memory, which might hurt the strong outlook that has boosted Micron, SK Hynix, and Samsung in 2026.

Steve Sosnick, chief strategist at Interactive Brokers, explained the risk clearly. Apple’s customers are much more sensitive to price changes than the large companies building AI data centers. Now that Apple has said it can’t keep absorbing higher memory costs, the big question is when these large data center operators might do the same. So far, they have been willing to pay high memory prices because AI infrastructure is so important to them, but that willingness has its limits.

Micron’s earnings report on Wednesday night was truly impressive, with revenue up four times and gross margins hitting 85%. The shortage of memory chips is expected to last at least another 18 months. However, the excitement on Thursday and the drop on Friday show just how sensitive this sector is to any sign that demand from consumers or businesses might weaken before the supply shortage ends.