Micron Earnings Smash Records, So Why Did Seagate and Western Digital Sink?

Micron earnings for its fiscal fourth quarter were the biggest in the company’s history: $54.2 billion of revenue, nearly five times a year earlier, and guidance that blew past forecasts. The stock slipped anyway. Two days later, hard drive makers Seagate and Western Digital fell 11% and 7% on Friday after rival Toshiba moved to double its hard disk output.

Same AI data-centre boom, very different reactions. Here is what Micron reported, why the storage names sold off, and what it tells traders about crowded trades.

Micron Earnings: A Record Quarter and a Bigger Forecast

Micron reported on 30 September for the quarter ending 3 September. Revenue of $54.23 billion beat the roughly $50.5 billion analysts expected and was up 379% year on year. Adjusted earnings of $33.42 a share topped the $31.16 forecast, and gross margin reached about 87%.

DRAM, the memory that includes the high-bandwidth memory (HBM) stacked next to AI chips, brought in $39.8 billion, about 73% of sales. Full-year revenue hit a record $133.2 billion, up 256%. For the current quarter, Micron guided to around $61.5 billion of revenue, well above the roughly $56.8 billion consensus, and said memory supply should stay tight through fiscal 2027 and 2028.

So why did Micron stock slip?

Expectations. Micron was up about 268% this year before the report, so even a beat-and-raise was met with profit taking. Investors also weighed Micron’s heavy spending plans, and the company faces the prospect of strike action in Taiwan, where a large share of its DRAM is made. A walkout there could disrupt supply at exactly the moment demand is strongest.

Why Did Seagate and Western Digital Stock Drop?

On Friday Seagate fell 11% and Western Digital dropped 7% after reports that Toshiba is preparing to roughly double its hard disk drive production to meet AI data-centre demand. Both companies have told investors that tight supply is what gives them pricing power. More capacity from a major rival threatens that, so the market marked down the margins it had been paying for.

The scale of the run made the drop sharper. Before Friday, Seagate shares were up around 210% this year and Western Digital about 150%. When a stock has rallied that far, any hint that the supply and demand balance could loosen sends traders for the exit.

“In a supply-constrained boom, the biggest threat is not weak demand. It is a competitor building more.”

Memory vs Storage: The Trade Is Splitting

The selloff stayed narrow. The Roundhill Memory ETF, which is dominated by Samsung, SK Hynix and Micron, barely moved on Friday, and the Nasdaq rose 1.2%. That points to an issue specific to hard drives, not a break in the wider AI memory story. Chip-based memory (DRAM and HBM) is still capacity-limited, while hard drive supply may now be about to grow.

How to Trade Chip and Storage Stocks

You can buy Micron, Seagate or Western Digital shares directly, or trade them with share CFDs, which let you go long or short. Many traders get exposure to the whole group through the Nasdaq 100 instead of picking single names. Either way, these stocks swing hard around earnings and supply news, so keep sizes small and always set a stop-loss. See our best brokers for Nasdaq 100 and how to trade stocks guides.

The bottom line: Micron earnings showed the AI memory boom is still accelerating, but a stock up more than 250% needs more than a beat. And for hard drive makers, one rival’s expansion plan was enough to wipe out a week of gains.