Key Highlights

● STX shares fell 3.80% to $753.25 in Monday’s session on roughly 4.08 million shares, about $3.07 billion in dollar volume and 19th among US stocks.

● The selling came in a sector-wide pullback after China’s CXMT made key progress on a denser memory-cell design, even though Seagate does not make DRAM.

● The stock fell 10% on October 2 on reports that Toshiba plans to double hard disk drive capacity, and 9.5% on October 6 amid reports of a contest with Toshiba to buy TDK’s head business.

● Fiscal fourth-quarter revenue was $3.63 billion, up 48.5%, with non-GAAP EPS of $5.71.

Why did Seagate Technology (NASDAQ:STX) land among the most actively traded U.S. stocks on Monday? The main reason is price, not panic. The hard drive maker closed at $753.25, down 3.80%, on roughly 4.08 million shares. That is below its normal turnover, with a relative volume of 0.79. But at a share price this high, even an ordinary session adds up to about $3.07 billion in dollar volume, enough to rank 19th on the “Most active US stocks” list, which ranks names by price times volume.

The selling came during a sector-wide pullback in memory and storage shares. SanDisk (NASDAQ:SNDK) dropped about 6% in early trading and Seagate about 4%. The Roundhill Memory ETF also fell about 4%, and Micron (NASDAQ:MU), Western Digital (NASDAQ:WDC) and SK Hynix all traded lower, while the S&P 500 ETF was roughly flat. The trigger was news that ChangXin Memory Technologies, a Chinese DRAM maker, had made key progress on a denser memory-cell design and planned an AI data center product later this year. Seagate does not make DRAM. Still, memory and storage stocks tend to trade together on sector sentiment, and Seagate is also a holding in the Roundhill Memory ETF, so the selling spread to names with no direct exposure.

A Rough Stretch for the Stock

Monday’s drop added to a volatile two weeks. On October 2, Seagate fell 10% in morning trading, after reports that Toshiba planned to double its hard disk drive capacity, centered on its Philippines plant, to meet AI data center demand. Toshiba, the smallest of the three HDD makers, is targeting 30% of the market by capacity. That runs against the supply discipline Seagate’s management has stressed. On the company’s April 28 call, CEO Dave Mosley said, “The total number of units is not really increasing.”

On October 6, the shares fell 9.5% in the afternoon session, reflecting investor caution after a report said Seagate and Toshiba were in a multibillion-dollar contest to buy TDK’s HDD magnetic-head business, the components that read data from and write data to the spinning platters inside a drive. According to that report, Toshiba began talks with TDK in the spring and Seagate submitted a higher offer in the summer. Toshiba disputed the report, saying it “conflicts with Toshiba’s own account of developments,” and none of the companies had confirmed a deal. The possible acquisition, with its risk of higher debt and weaker free cash flow, is among the pressures on the stock, along with the Toshiba capacity plan, recent insider selling and caution ahead of upcoming earnings.

The stock was still up 174.4% year to date after Monday’s close, and was well below its 52-week high.

What Seagate Does

Seagate describes itself as a pioneer in mass-capacity data storage, selling drives to hyperscale cloud providers, enterprises and consumers. It is legally domiciled in Dublin, Ireland, and its operational headquarters is in Fremont, California. Its core business is high-capacity nearline hard drives, which sit in the bulk storage tier of cloud and AI data centers. The company is pushing its Mozaic platform, built on heat-assisted magnetic recording (HAMR), to pack more data onto each drive. Seagate said in April that its nearline capacity was almost fully allocated through calendar 2027.

Latest Results and Guidance

The most recent report came on July 28. For fiscal fourth-quarter 2026, which ended July 3, Seagate posted revenue of $3.63 billion. That beat the $3.50 billion consensus and was up 48.5% from a year earlier. Non-GAAP earnings per share were $5.71, against a $5.10 estimate and $2.59 a year earlier. Non-GAAP gross margin reached 52.7%. Free cash flow for the quarter was $1.1 billion.

For the full fiscal year, revenue rose 34% to $12.2 billion. Non-GAAP EPS was $15.58 and free cash flow was $3.1 billion, and the company retired $1.4 billion of debt. “As AI accelerates data generation and its value, we see durable long-term demand for mass capacity storage,” Mosley said in the release.

The outlook implies growth continues. Seagate guided fiscal first-quarter 2027 revenue to $4.1 billion, plus or minus $100 million, and non-GAAP EPS to $7.30, plus or minus $0.20. The company pays a quarterly dividend of $0.74 per share, most recently paid on October 7.

Valuation

Based on trailing earnings, Seagate looks expensive. The P/E is 54.29 on trailing EPS of $13.87, and the trailing multiple is well above the stock’s five-year median of 22.0. The forward picture looks very different because profits are rising so quickly. The forward P/E is 20.8. Analysts expect $35.70 in EPS for the current fiscal year.

Analysts remain largely positive. The tally shows 22 Buy ratings and 5 Holds, with an average price target of $986, well above Monday’s close. In late July, after earnings, Rosenblatt raised its target to $1,400, Wells Fargo (NYSE:WFC) raised its target to $1,180, and JPMorgan (NYSE:JPM) raised its target to $1,240. One discounted cash flow model suggests the shares could be about 36% undervalued, while another measure of fair value is far below the current price.

Bull Case versus Bear Case

The bull case rests on a tight, consolidated industry and the volume of data AI produces. Only three companies make hard drives, demand for mass-capacity storage is growing, and Seagate has said its nearline output is largely spoken for through 2027. That gives the company pricing leverage, and HAMR could widen its technology lead. Seagate beat estimates in every quarter of fiscal 2026.

The bear case starts with supply. If Toshiba doubles its capacity, the industry’s pricing power could weaken just as investors have priced in years of strong margins. A contested bid for TDK’s head unit could mean higher spending and debt. Insiders have been sellers, having sold 466,959 shares worth about $378.8 million over three months, which the company described as covering taxes on vesting equity. With a beta of 2.06 and 70 moves greater than 5% in the past year, the stock is prone to sharp swings when sentiment shifts.

Seagate’s Next Catalysts: Earnings, TDK and Toshiba

The next big catalyst is Seagate’s fiscal first-quarter 2027 report. The date has not been confirmed. Investors will want to see whether revenue lands near the $4.1 billion midpoint and whether margins keep rising despite the Toshiba news. Any official word on the TDK magnetic-head process, and on how quickly Toshiba’s new capacity reaches cloud buyers, could move the shares. Investors will also watch whether the memory sell-off sparked by the ChangXin news fades or spreads, since Seagate has shown it can be pulled along by DRAM headlines even though it does not make DRAM.