Sandisk Stock Surges on AI Memory Demand as Investors Weigh Whether the Rally Is Still a Buy Now

NEW YORK — Sandisk shares jumped again as investors treated a former flash-drive name like an artificial-intelligence infrastructure stock, leaving a simple question after a violent rally: whether the tape still offers a buy, or only a bet that memory prices stay scarce.

Sandisk closed Sept. 4 at $1,740, up $185.01, or 11.90%, from the prior session. Overnight trading printed about $1,767. The session’s range ran from $1,581 to $1,740. The 52-week span, from about $68 to more than $2,350, shows how fast the story changed after the company was spun out of Western Digital in early 2025.

The move follows fiscal fourth-quarter results for the period ended July 3. Revenue was $8.97 billion, up 51% from the prior quarter and 372% from a year earlier. Data-center sales were $2.98 billion, about a third of the quarter and more than double the prior period. A year earlier that line was about $213 million. Non-GAAP gross margin reached 84.6%, compared with 26.2% a year earlier. Adjusted earnings were reported well above year-ago losses. Management said about two-thirds of the sequential revenue increase came from higher prices and one-third from more bits shipped.

Guidance kept the heat on. For fiscal first-quarter 2027, Sandisk forecast revenue of $10.3 billion to $10.80 billion and non-GAAP profit of $44 to $46 a share, with gross margin 83% to 85%. Reuters noted the revenue midpoint sat above one consensus set even as the stock sold off after the print when other estimate services had wanted more.

Chief Executive David Goeckeler has framed the boom as structural, not seasonal. “AI is fundamentally a memory-centric storage-intensive problem,” he said on the August earnings call. At the company’s investor day he said, “Our strong performance today is the direct result of disciplined execution against the strategy we outlined 18 months ago.” He has also said Sandisk grows supply “primarily through nodal transitions rather than wafer additions.”

That last point is why bulls call the stock a buy on a pullback and why skeptics wait. Memory cycles have historically ended when suppliers add wafers and prices collapse. Sandisk is arguing it can lift bits in the mid-to-high teens by moving to denser technology such as BiCS8 without a classic capacity binge. Capital spending is described as modest relative to sales. The long-term model for fiscal 2028 through 2030 targets mid-to-high-teens revenue growth, about 80% non-GAAP gross margin, about 75% operating margin and adjusted free cash flow near 50% of revenue. Those figures are below the 84.6% gross margin just printed, which is management’s way of telling the market the peak print may not be the mid-cycle print.

Contracts are the other half of the bull case. Chief Financial Officer Luis Visoso said Sandisk had 10 multiyear “new business model” agreements with eight customers, five signed since April, running as long as five years with a weighted average duration of more than four years. “The total expected revenue from all our NBMs we have signed is a minimum of $93.9 billion, assuming floor pricing,” Visoso said. Management has said the deals should cover about half of bits in fiscal 2027 and about two-thirds in fiscal 2028, backed by customer deposits and other financial support. That is closer to a contracted industrial book than to the spot NAND market Sandisk used to live in.

The company also authorized large buybacks as cash piled up. It repaid remaining term-loan debt, moved to a net cash position and later expanded repurchase authority into the tens of billions. Full-year free cash flow swung from an outflow in fiscal 2025 to more than $11 billion in fiscal 2026 on company figures. S&P Global Ratings raised Sandisk to BB+ with a positive outlook after the deleveraging, citing constrained NAND supply through fiscal 2027 in its base case.

None of that answers “buy now” as a binary. At $1,740 the stock is no longer the neglected spinoff that traded in the double digits. It has already discounted a multiyear AI storage cycle. Trailing earnings multiples compressed as profits exploded; forward estimates imply a lower multiple if guidance holds. That can look cheap if $10 billion-plus quarters continue. It looks expensive if NAND prices normalize the way they have after every prior shortage.

The risks are familiar. Edge products — phones, PCs, cards — still supply more than half of quarterly revenue even as data center grows faster. Consumer units can drop just as data-center contracts lock in. Competitors in NAND and SSDs can still add supply. Customer concentration in a handful of AI builders means a pause in GPU cluster builds would hit Sandisk with a lag, not instantly, but it would hit. Gross margins in the mid-80s have little room to surprise to the upside and a long way to fall if floor prices in the new contracts sit well below spot.

Goeckeler has said customers returned after a single quarter asking to raise three-to-five-year demand. He estimated the NAND market would exceed $300 billion in calendar 2026, triple the prior year, and approach $500 billion in 2027, with data center taking a larger share of the total. Those are company forecasts, not booked sales.

For a newsroom ledger, the buy case is this: constrained bits, contracted floors, high cash conversion, and a CEO who says the shortage is an AI architecture problem rather than a one-year restock. The hold-or-wait case is this: the stock already ran from spinoff leftovers to a triple-digit handle, August’s 29% bounce recovered a prior slide, and Sept. 4’s 12% pop prices in another quarter of $10 billion sales before that quarter is delivered.

Sandisk is no longer asking investors to believe flash cards will matter. It is asking them to believe memory stays scarce long enough for $94 billion of minimum contract value to turn into cash at margins the old Sandisk never earned. Whether that is a buy at $1,740 depends less on the closing print than on whether the next shortage ends on schedule — or, this time, does not.