The profit on a hard drive suddenly looks like that of an AI chip.
U.S. storage company Western Digital's latest FY2026 Q4 earnings release reported revenue of $3.747 billion. On a GAAP basis, earnings per share were $8.21. According to the company's announcement, the fair value remeasurement gain on its SanDisk stake was also included in the income statement.
This gives Western Digital's results two layers of interpretation. The first is that the core HDD business, after spinning off the flash memory business, sold more and became more profitable. The second is that its retained SanDisk equity fluctuated with market value, pushing GAAP profit to a level not suitable for directly measuring the hard drive business.
This is not a one-quarter jump
Let's start with the most basic question. Is this growth only happening in one quarter?
According to Western Digital's FY2026 Q4 earnings release and prior Form 10-Q, the revenue curve from FY2025 Q4 to FY2026 Q4 does not turn downward. It rose from $2.605 billion to $3.747 billion, with five actual quarters forming a continuous upward line.
The reason this line is worth looking at as a whole is that the basis has changed. Western Digital completed the spin-off of its flash memory business in February 2025, and the independent SanDisk is no longer consolidated into continuing operations. The latest earnings release also restated prior comparable periods on an HDD continuing operations basis. The growth in the chart is not the result of adding back the SSD business, but rather the pure hard drive business expanding.
According to the company's earnings presentation on the same day, the cloud market accounted for 89% of Q4 revenue. This end-market label is not equivalent to AI revenue, but it shows that Western Digital's main revenue now comes from hyperscale cloud vendors and cloud service providers. Hard drives in this chain do not provide computing power but provide large-capacity data storage.
According to the company's FY2026 Q4 earnings release, the midpoint of FY2027 Q1 revenue guidance is $4.1 billion. For readers, the reminder that the dashed line is more important than the solid line is that guidance can only be taken as the company's current judgment, not as a fait accompli for the next quarter.
Selling more and retaining more profit
Higher revenue does not automatically mean a better business. This is especially true in the hard drive industry, where during an upcycle, shipments, prices, inventory, and capacity utilization all squeeze into the income statement at the same time. What really matters is how much is left from every $100 of revenue.
According to the company's financial report, GAAP gross margin for FY2026 Q4 reached 54.1%. In more intuitive terms, for every $100 of storage products sold, more than half remains after deducting direct manufacturing costs.
Compared with a year ago, the gross profit left from every $100 of revenue is about $13 more. The other operating margin curve in the chart also rises at a similar slope, indicating that R&D, sales, and administrative expenses did not eat up the incremental gross profit.
Here, the two lines cannot be simply attributed to a single product or a single customer. The earnings release itself only tells the market that cloud and other data-intensive workloads are expanding, and demand for Western Digital's products is increasing accordingly. It does not break out "AI" as an auditable revenue line item. What is certain is that revenue growth and margin expansion occurred simultaneously over five quarters, and the incremental revenue clearly flowed through to operating margin.
Cash flow adds another check to this improvement. Free cash flow for FY2026 Q4 was $1.281 billion, and according to the company's earnings release, cash flow from operations was $1.389 billion. Hard drives remain a manufacturing business that requires equipment, materials, and inventory turnover. Cash keeping pace with profit provides another validation of the quarterly operating results. It alone cannot prove that the trend will continue forever, but it is closer to the funds the company can actually deploy than looking at the income statement alone.
Where exactly does EPS come from
So why does GAAP earnings per share look more exaggerated than the improvement in the core business? The answer lies in the last chart.
GAAP net income attributable to continuing operations for FY2026 Q4 was $3.195 billion. On the company's defined Non-GAAP basis, this figure is $1.382 billion. The difference is not a calculation error, but rather the company excludes certain items not intended for comparing ongoing operating performance from the latter.
The largest item is a $2.050 billion gain on the retained SanDisk equity. It comes from the fair value remeasurement of Western Digital's stake in SanDisk, not from selling more hard drives this quarter. In the same reconciliation table, the company also added back costs related to debt and equity transactions, and made adjustments for taxes, stock-based compensation, and restructuring items.
This does not mean Non-GAAP is the only "true profit." It is still a comparison basis defined by the company and should be read alongside GAAP. Its value lies in separating changes in equity market value from the operating results of hard drive manufacturing and sales. If you only focus on $8.21, it is easy to treat two different types of gains as the same thing.
The most interesting part of Western Digital's earnings report is not that a hard drive suddenly has a chip-like valuation narrative, but that after spinning off flash memory, the HDD core business's revenue and margins have indeed thickened together. The SanDisk stake makes GAAP profit look brighter, but when you strip it away, the remaining hard drive business is no longer what it was in the previous cycle.
