Key Highlights

● STX shares rose 4.49% to $887.09 on Monday, October 5, on 5.59 million shares, about 1.28 times normal volume.

● Seagate fell 10.21% on Friday, October 2, after reports that Toshiba plans to double its hard-drive capacity for AI data centers by fiscal 2027.

● Bernstein reiterated its Outperform rating, Morgan Stanley said Toshiba's expansion roughly matches market growth, and Goldman Sachs named Seagate a top tactical pick ahead of earnings.

● Fiscal fourth-quarter Revenue was $3.63 billion, up about 49%, and Seagate guided fiscal first-quarter revenue to $4.1 billion, plus or minus $100 million.

What sent Seagate Technology (NASDAQ:STX) back up the most-active list on Monday was a sharp Reversal of Friday's scare. The hard-drive maker rose 4.49% to $887.09 on 5.59 million shares, about 1.28 times its normal volume, after a cluster of brokerages argued that the previous session's sell-off had misread news out of Japan. With the stock trading near $900 a share, even modestly elevated Volume translated into roughly $4.96 billion changing hands, enough to rank 17th among US stocks by dollar volume.

What's driving the volume

The story starts on Friday, October 2. Reports that Toshiba plans to double its hard-drive Manufacturing capacity for AI data centers by fiscal 2027, including expansion in the Philippines, hit the whole storage group. Seagate fell 10.21% that day, after trading more than 13% lower early in the session, while Western Digital (NASDAQ:WDC) dropped around 7%. The worry was simple: if a third supplier adds a lot of nearline capacity, the tight market that has let Seagate raise prices could loosen.

By Monday, analysts were pushing back. Bernstein reiterated its Outperform rating and called the reaction "misunderstood." Citi (NYSE:C) argued that the hard-disk industry is under-shipping Demand by a wide Margin and noted that Toshiba relies on outside suppliers for key components, which could limit how fast it can actually add output. Morgan Stanley (NYSE:MS) told clients to buy the dip, saying Toshiba's expansion roughly matches market growth rather than creating a glut, and Goldman Sachs (NYSE:GS) named Seagate a top tactical pick ahead of earnings, looking for modest upside to revenue and guidance. Western Digital, the closest US peer, climbed 6.34% on the day, so the rebound was sector-wide rather than company-specific.

The broader tape helped. The Nasdaq Composite gained 1.05% on Monday as technology momentum overrode a jump in the 10-year Treasury Yield to 5.31%, its highest level since 2002, and softer jobs data eased fears of further Fed rate hikes. AI infrastructure names, from Nvidia (NASDAQ:NVDA) to Broadcom (NASDAQ:AVGO), were bid, and storage is increasingly traded as part of that complex.

The business

Seagate designs and manufactures hard disk drives and related storage systems. The company has largely moved away from PCs and consumer devices toward mass-capacity nearline drives sold to cloud providers and large enterprises, the drives that hold the enormous volumes of data generated and consumed by AI workloads. Its technology edge is heat-assisted magnetic recording, sold under the Mozaic brand. Mozaic 4 drives with 44 terabytes per unit are in production, and a 50-terabyte Mozaic 5 is targeted for qualification in late 2027. Because HAMR lets Seagate add capacity per platter rather than build more drives, it can grow exabytes shipped without adding as much manufacturing footprint, which supports margins.

Recent results and guidance

Seagate's most recent report, for its fiscal fourth quarter ended in early July, was strong. Revenue came to $3.63 billion, up about 49% from a year earlier and ahead of consensus. Non-GAAP Earnings per share were $5.71, and non-GAAP gross margin reached 52.7%, a remarkable level for a Business that was once viewed as a cyclical Commodity supplier. For fiscal 2026 as a whole, revenue was $12.2 billion and free Cash Flow was $3.1 billion. The company pays a quarterly Dividend of $0.74 per share.

Guidance points to further acceleration. For the fiscal first quarter, Seagate forecast revenue of $4.1 billion, plus or minus $100 million, and non-GAAP EPS of $7.30, plus or minus $0.20. CEO Dave Mosley said performance was being driven by robust cloud Data Center demand and that the company sees momentum continuing into 2027. Management has said nearline capacity is almost fully allocated through calendar 2027, with contracted pricing locked in, which is precisely why bulls argue a Toshiba expansion years away does not change the near-term picture. The next report is expected in late October.

Valuation

On trailing GAAP earnings, Seagate looks expensive: its P/E is 63.94, against 18.27 for Western Digital, 23.38 for Sandisk (NASDAQ:SNDK) and 14.34 for Micron (NASDAQ:MU). That headline number overstates the premium, because trailing earnings lag the steep ramp now under way. If the company annualizes its current-quarter EPS guidance, the forward multiple falls to roughly 30 times, and another estimate puts it at about 25 times forward earnings.

Even so, investors are paying a richer price than for other memory and storage names, partly because Seagate's long-term contracts make its earnings look more visible. The stock had gained about 250% over the previous 12 months, and the year-to-date advance is around 209%. Even after Monday's rebound, the shares remain below their 52-week high of about $1,094, set in June, which gives some sense of how much enthusiasm has already been priced in and how quickly it can be taken back out.

Bull case

Supporters point to a demand picture that is still outrunning supply. AI Training and inference generate large amounts of data that must be stored cheaply, and hard drives remain far less expensive per terabyte than flash. Allocated capacity through 2027, rising gross margins, a technology lead in HAMR and strong free cash flow give Seagate room to keep raising its dividend and buying back stock. Several major brokerages defended the shares within a single trading day of the Toshiba news.

Bear case

Skeptics argue that Friday's reaction is a preview of the main risk: hard drives have been a boom-and-bust business, and any sign that Supply will catch up with demand can compress the multiple quickly. Toshiba's plans, a possible slowdown in hyperscaler Capital spending, or price pressure when current contracts roll over could all hurt. The stock's big run also leaves less room for disappointment, and daily swings of 5% to 10% have become routine.

Seagate's late-October report and the Toshiba question

The next major test is Seagate's fiscal first-quarter report, expected in late October, where investors will look for results in line with the $4.1 billion revenue guide, commentary on pricing for 2027 and 2028 contracts, and any update on Mozaic 5. Further details on the scale and timing of Toshiba's expansion, Western Digital's results and hyperscaler capital-spending commentary during October earnings season will shape whether Friday's sell-off proves to be a buying opportunity or an early warning.