For most of 2026, the bull case for the HDD duopoly could be summarized in one sentence: nobody is building new factories. On Friday, someone did.
Shares of Seagate (STX) and Western Digital (WDC) tumbled more than 10% on Friday, standing out like a sore thumb on a day when the Nasdaq hit all-time highs, after Nikkei reported that Toshiba plans to double its hard disk drive production capacity to grab a bigger slice of the AI data center storage boom.
This is how Goldman's TMT desk summarized the Nikkei story first thing in the morning (full note available to pro subs):
Japanese technology group Toshiba plans to double production capacity for hard disk drives used in artificial intelligence data centers within fiscal 2027 as the AI boom propels data storage demand. The company will invest roughly 60 billion yen ($380 million) to expand facilities in the Philippines... The Japanese player's share by storage capacity stands at just over 10%, but it aims to reach 30% in the medium term. The Philippine expansion marks the company's first major HDD investment in around five years. Along with adding production lines at the plant, Toshiba will handle new products that increase per-unit memory capacity by as much as 40%.
By midday, Goldman's US equities desk flagged the "memory names, WDC (-10.9%) and STX (-11.6%)" as the "standout laggards" in an otherwise green tape, where AI winners were up 1.4% and NDX and NVDA had just printed all-time highs.
To be sure, a 10% drop is just
