Memory and data storage stocks tumbled on Thursday after the group saw investors rush into the names over the past six months, fueled by the artificial intelligence spending boom.
Sandisk (SNDK) shares fell more than 10% on Thursday, while Micron (MU) tumbled more than 4%. Western Digital (WDC) and Seagate Technology (STX) saw declines of 8% and 7%, respectively.
Despite Thursday’s drawdowns, the quartet saw strong runs in the bach-half of 2025 and first few trading days of 2026, led by Sandisk. Sandisk’s market cap has increased more than 800% over the past 12 months, while Micron has risen more than 220%. Western Digital and Seagate have increased 280% and 224%, respectively, over the same time frame.
The sharp declines in the stocks of the aforementioned companies comes on the same day that memory industry stalwart Samsung (SSNLF) forecasted a record-high quarterly operating profit in the fourth-quarter, mainly owing to tight supplies and the AI boom. The company expects revenue to be between 92T and 94T Korean won, while operating profit is expected to be between 19.9T and 20.1T Korean won, largely due to rising memory prices.
It was reported earlier this week that Samsung and SK hynix (HXSC.F), the two biggest memory makers, are discussing raising prices for server memory by up to 70% in the first quarter.
Micron reported its most recent quarterly results and guidance in December that were significantly better-than-expected. As such, a number of Wall Street firms said the company is in the midst of a “memory supercycle.”
Last month, Wedbush Securities analyst Matt Bryson said that the surge in demand for memory that started in March 2025 became “even more pronounced in Q4.”
“While we believe Nanya (and to some extent module makers) are benefitting from DDR4 shortages tied to the rapid EOL of this product set, we see strength now as much broader based due to unexpected upticks in demand from [cloud service providers] in the August and September periods which have created shortages throughout DRAM and NAND,” Bryson said. “We now expect trends will continue into 2026, with [cloud service providers] having significantly lifted their outlook for requirements through next year.”