Sandisk’s closest manufacturing partner just fell 15.8% in Tokyo after giving a December-quarter profit forecast roughly 15% below consensus, but the read-through to Sandisk stock is less straightforward than the headline suggests.Kioxia Holdings closed Monday down 15.78% after falling as much as 17% intraday. The drop followed results released after the Japanese market closed on October 30, when the NAND flash maker forecast about ¥2 trillion of adjusted operating profit for October through December against market expectations of roughly ¥2.32 trillion to ¥2.35 trillion.The Nikkei finished at 63,081.86, down 208.25 points, or 0.33%, with Kioxia the biggest drag on the index, according to Reuters.Sandisk initially went the other way. It traded roughly 2.5% to 3% higher before Monday’s U.S. open, while Micron gained more than 2%. That divergence weakened once regular trading began. A later intraday read had Sandisk around $1,130, down roughly 1.8% from Friday’s $1,150.89 close, while Micron had also turned about 1% lower.The question for Sandisk investors is therefore not whether Kioxia matters. It clearly does. The question is how much of Kioxia’s guidance miss reflects the NAND market Sandisk shares with it, and how much comes from Kioxia’s own shipment timing, currency exposure and customer mix.
Kioxia’s Record Quarter Was Not the Problem
The September quarter itself was exceptionally strong.Kioxia reported revenue of ¥2.48 trillion for July through September, up about 453% from a year earlier and 40% sequentially. Adjusted operating profit reached ¥1.9883 trillion, producing an 80.2% adjusted operating margin.Kioxia’s official October 30 results show that the company expects December-quarter revenue of ¥2.5 trillion, up only 0.8% sequentially, and adjusted operating profit of ¥2 trillion, up 0.6%.That is the part investors punished. Bloomberg described the outlook as one that “suggests demand leveling off,” rather than Kioxia itself declaring that NAND demand has stopped growing.The distinction matters because management gave several company-specific reasons for the near-flat guide.Chief Financial Officer Yoshihiko Kawamura said Kioxia’s forecast absorbs roughly ¥55 billion of foreign-exchange pressure from assuming the yen strengthens from about ¥161 to ¥157 per dollar. Some customer orders that had originally been expected in the December quarter were also pulled forward into the September quarter because demand was unusually strong.At the same time, some enterprise-storage orders moved into the January-March quarter because those products require longer manufacturing and delivery cycles.Kioxia therefore says the December-quarter shape is partly about timing, not simply weaker end demand. Management expects stronger shipment growth in the March quarter and says planned 2027 capacity is already allocated, with long-term agreements covering more than half of expected 2028 shipments.
Why Kioxia Matters Directly to Sandisk Stock
The relationship between the two companies goes much deeper than two NAND manufacturers selling into the same market.Sandisk and Kioxia jointly develop and manufacture flash-memory wafers through three Flash Ventures entities. Sandisk owns 49.9% of those ventures and Kioxia 50.1%. Kioxia operates the Japanese fabrication facilities, while the ventures buy wafers from Kioxia and resell them to both companies.Sandisk has previously disclosed that substantially all of the flash-based memory used in its products comes through those ventures.That makes Kioxia’s production economics, NAND pricing and capacity decisions directly relevant to Sandisk. In August, the companies went further, announcing plans for more than $31 billion of additional investment in Japan through 2032.The pricing relationship has already been central to the Sandisk investment case. FinanceFeeds reported in September that Kioxia was trying to prevent further NAND price increases from damaging longer-term demand after prices had risen about 70% in a quarter.The latest results show that pace has already moderated. Kioxia said its blended NAND average selling price increased in the mid-20% range sequentially in the September quarter, compared with roughly 70% in the previous period.That does not mean NAND prices are falling. Kioxia’s own commentary indicates they are still rising, just at a slower rate.
Sandisk’s Own Guide Is Stronger Than Kioxia’s
The argument against treating Monday’s Kioxia fall as a one-for-one Sandisk signal is Sandisk’s own earnings report.Sandisk reported fiscal first-quarter revenue of $11.03 billion, up 378% year over year and 23% sequentially, then guided the current quarter to $12.2 billion to $12.6 billion. Its non-GAAP gross-margin guide is 84.5% to 85.5%.FinanceFeeds’ week-ahead analysis after Sandisk’s 13.47% Friday drop noted that the company also has long-term agreements covering about half of fiscal 2027 bit supply and roughly two-thirds of fiscal 2028.In other words, Sandisk and Kioxia share manufacturing infrastructure and the same broad NAND cycle, but they do not have identical shipment schedules, customers or quarterly revenue recognition.That explains why Kioxia could guide adjusted operating profit almost flat while Sandisk is still guiding another double-digit sequential revenue increase.It also explains why Monday’s premarket reaction initially diverged. TradingKey had Sandisk up more than 3% and Micron more than 2% even after Kioxia had closed down 15.8% in Tokyo. The fact that both U.S. stocks subsequently surrendered those gains leaves the market’s final read less decisive.
The Sandisk Read-Through Is Pricing, Not One Quarter’s Shipment Timing
For Sandisk shareholders, the most useful part of Kioxia’s results is therefore not the ¥2 trillion headline by itself.The bigger signal is what happens to NAND pricing after a year of exceptional increases.If Kioxia’s slower ASP growth reflects only product mix, foreign exchange and orders moving between quarters, Sandisk’s own demand and guidance can continue to diverge. If slower price increases become an industry-wide pattern, the read-through becomes much more important because Sandisk’s recent earnings expansion has depended heavily on unusually strong NAND pricing and data-center demand.That question comes after Sandisk stock already fell 13.47% on October 30 to $1,150.89 following its own results.There is also a mechanical change coming later this month. Sandisk has announced an eight-for-one forward split, with additional shares distributed after the close on November 19 and split-adjusted trading beginning November 20. FinanceFeeds has a full breakdown of the Sandisk stock split and how existing prices and earnings figures convert.Monday’s Kioxia selloff does not establish that Sandisk’s outlook has deteriorated. It does, however, put another data point behind the question investors are already asking after Sandisk’s own post-earnings decline: how much longer can NAND pricing grow at the rates that produced this year’s extraordinary margins?
