Sandisk stock has turned into one of Wall Street’s wildest AI trades, soaring roughly 628% from around $235 at the start of 2026 while swinging between record highs and brutal double-digit pullbacks. The latest hedge-fund filings reveal an extraordinary split: Leopold Aschenbrenner’s Situational Awareness piled deeper into SNDK before July’s crash, while billionaire David Tepper’s Appaloosa dumped its entire position.
That disagreement comes as Sandisk’s fundamentals appear stronger than ever. Fiscal fourth-quarter revenue jumped to $8.97 billion, AI-driven data-center demand is surging, and management now expects mid-to-high-teens annual revenue growth from fiscal 2028 through 2030.
The problem is the stock price.
At roughly $1,781 on August 17, SNDK carries a market capitalization near $280 billion after rising another 8.5% Monday. Investors are now debating whether Sandisk represents a structural winner from AI—or one of the most dangerous momentum trades on Wall Street.
Hedge Funds Are Split on Sandisk Stock
Second-quarter 13F filings show just how divided sophisticated investors became as Sandisk raced higher.
Situational Awareness, the fund run by former OpenAI researcher Leopold Aschenbrenner, increased its Sandisk holding by roughly 1.36 million shares during the quarter. By June 30, SNDK represented approximately 28% of the fund’s disclosed long U.S. equity portfolio.
Combined with Micron, memory stocks accounted for more than 56% of the portfolio.
That concentration became disastrous when the AI trade suddenly reversed.
Between the end of June and July 30, Sandisk shares plunged approximately 43%, while Micron fell around 24%. Situational Awareness ultimately negotiated a rescue transaction with Citadel after leverage magnified the losses across its technology-heavy portfolio.
The filing is particularly striking because it captures the fund’s holdings immediately before that collapse.
Then there is David Tepper.
Appaloosa Management moved in precisely the opposite direction, selling its entire 281,250-share Sandisk positionduring the second quarter. Tepper had only established the stake in Q1, meaning he exited while SNDK was still deep into its extraordinary rally.
The contrast could hardly be sharper.
One high-profile investor dramatically increased exposure.
Another walked away completely.
The Sandisk Stock Rally Has Been Almost Unbelievable
The reason hedge funds are struggling with SNDK is simple: the stock has moved far faster than almost anyone expected.
Sandisk began 2026 near $235 and later surged above $2,300 at its June peak. By August 12, shares had fallen roughly 43% from their 52-week high to around $1,344 before rebounding sharply following the company’s Investor Day.
The volatility has been extreme even by semiconductor standards.
Sandisk rose 13.7% on August 13 after management released its long-term financial framework, then continued climbing. By August 17, shares were near $1,781 after another 8.5% gain.
Yet the stock remains more than 20% below its record high.
That combination—a huge year-to-date gain, a violent correction and a rapid rebound—is precisely the type of environment where hedge funds can reach dramatically different conclusions about valuation and risk.
For bulls, the pullback created another entry point.
For bears, it demonstrated how quickly a crowded AI trade can unravel.
Earnings Explain Why Bulls Refuse to Leave
The fundamental numbers behind Sandisk stock are extraordinary.
Fiscal fourth-quarter revenue reached $8.97 billion, up 51% sequentially. GAAP net income hit $6.90 billion, equal to $43.97 per diluted share, while adjusted earnings came in at $39.25 per share.
The pricing environment was particularly powerful.
Sandisk said roughly two-thirds of its sequential revenue growth came from higher prices, with the remaining one-third attributable to increased volume.
That follows an equally explosive fiscal third quarter.
Q3 revenue reached $5.95 billion, up 97% sequentially, as data-center revenue surged 233%. Sandisk said the results reflected higher pricing and a shift toward higher-value customers.
Only two quarters earlier, fiscal Q2 revenue was $3.03 billion.
The speed of the increase demonstrates just how dramatically the economics of NAND flash memory have changed as artificial-intelligence infrastructure builders consume enormous amounts of storage.
AI Data Centers Have Changed the NAND Market
Traditional NAND memory has historically been brutally cyclical.
Manufacturers add capacity when prices rise, supply eventually exceeds demand, prices collapse and profits disappear.
Sandisk is trying to convince investors that AI is changing that model.
Modern AI infrastructure does not need only Nvidia GPUs and high-bandwidth DRAM. It also requires huge amounts of fast storage for datasets, model checkpoints, inference workloads and data movement.
That is creating a new growth opportunity for NAND suppliers.
At its August 13 Investor Day, Sandisk forecast mid-to-high-teens annual revenue growth between fiscal 2028 and 2030. The company also expects adjusted gross margins to remain around 80% during that period.
Those margins are extraordinary for a company operating in what historically has been a commodity-like memory market.
Management believes long-term customer contracts can help make the economics more durable.
Sandisk Just Locked Up Huge Amounts of Future Demand
The most important part of Sandisk’s Investor Day may have been its new customer-contract strategy.
The company said its new business model now includes agreements with eight customers, including three U.S. hyperscalers. Those contracts cover approximately half of Sandisk’s storage output in fiscal 2027 and about two-thirds in fiscal 2028.
That visibility is designed to reduce the boom-and-bust character of NAND.
Instead of producing enormous quantities of memory and hoping demand appears, Sandisk is increasingly linking future capacity to committed customer volumes.
The strategy could make earnings significantly easier to forecast.
And it directly addresses one of the biggest bearish arguments surrounding SNDK stock: that current profits simply represent the peak of another memory cycle.
If large cloud providers are effectively reserving future output years in advance, Sandisk may have more pricing power than it did in previous cycles.
That is the bull case Wall Street is now trying to price.
High-Bandwidth Flash Could Be Sandisk’s Next AI Catalyst
Sandisk is also developing a new technology designed specifically for artificial intelligence.
High Bandwidth Flash, or HBF, attempts to combine the capacity advantages of NAND flash with dramatically faster data-transfer speeds.
The technology is aimed partly at AI inference, where systems must retrieve and process increasingly large quantities of data as models grow.
Sandisk and SK Hynix have already advanced an Open Compute Project technical specification for HBF, while Sandisk and Kioxia announced another high-performance QLC 3D flash technology in August targeted at AI and data-intensive applications.
If HBF becomes an important layer in AI servers, Sandisk could gain another source of growth beyond conventional enterprise SSDs.
But investors should not price that opportunity as guaranteed revenue.
HBF is an emerging technology, and adoption rates, competitive designs and future economics remain uncertain.
Why David Tepper May Have Sold Sandisk Stock
Appaloosa’s exit does not necessarily mean Tepper expects Sandisk’s business to collapse.
13F filings reveal positions, not investment reasoning.
They also arrive with a delay.
Appaloosa’s filing reflects holdings as of June 30, so the fund’s current portfolio may already differ substantially.
Still, the timing is notable.
Sandisk had already delivered an enormous gain when Tepper sold all 281,250 shares. Appaloosa simultaneously reduced its Micron exposure by roughly 41%, suggesting broader profit-taking from the memory trade rather than a Sandisk-specific rejection.
Valuation may also have mattered.
At approximately $1,781, Sandisk trades at roughly 62 times trailing earnings and carries a market value near $280 billion.
That is an aggressive valuation for an industry historically known for violent cycles.
Even excellent companies can become poor investments if too much future growth is already embedded in their stock prices.
The Situational Awareness Collapse Shows the Other Risk
The opposite strategy produced an even more dramatic lesson.
Situational Awareness entered July with roughly 28% of its disclosed equity book in Sandisk and another 27.5% in Micron. Its five largest disclosed positions represented approximately 77% of the portfolio.
That concentration amplified the damage when AI and memory stocks reversed.
Reuters separately reported that crowded technology trades suffered badly during July as investors attempted to unwind positions simultaneously. JPMorgan described the episode as particularly difficult because many funds were trying to capture gains at the same time.
The takeaway for ordinary SNDK investors is not necessarily that Sandisk is overpriced.
It is that position sizing matters enormously in a stock capable of moving 40% in a matter of weeks.
A strong fundamental thesis does not eliminate market risk.
Is Sandisk Stock Still a Buy After the 628% Rally?
The bull case remains formidable.
Revenue is exploding.
Data-center demand is accelerating.
Long-term customer agreements cover substantial future output.
Management expects double-digit growth through the end of the decade.
And Sandisk is developing new technologies specifically aimed at AI workloads.
The bear case is equally straightforward.
SNDK has already undergone an enormous valuation re-rating, trades at a premium multiple and remains exposed to a memory industry where supply additions can eventually crush prices.
Morningstar recently argued that Sandisk, Micron and Seagate were trading well above its estimates of intrinsic value, warning that new memory supply expected around 2028 could eventually pressure earnings growth.
That is exactly when Sandisk’s own long-term forecast becomes critical.
Management believes the new contract structure can prevent history from repeating.
Investors are betting billions that it is right.
Outlook: The Next Sandisk Stock Move Could Be Violent
The hedge-fund filings have turned Sandisk into a fascinating Wall Street battleground.
Situational Awareness showed how aggressively believers were willing to chase the AI-memory boom.
Appaloosa showed that one of the world’s most successful investors was willing to cash out despite spectacular operating momentum.
Now the stock sits between those two views.
At roughly $1,781, Sandisk is recovering rapidly from July’s collapse but remains below its June record.
Investors should watch data-center revenue, NAND pricing, hyperscaler contract coverage, HBF adoption and whether management can actually sustain anything close to its targeted 80% adjusted gross margins through 2030.
If AI storage demand remains structurally undersupplied, Sandisk’s rally may still have another chapter.
But after a 628% surge and one spectacular hedge-fund blowup, the next surprise in SNDK may be just as violent as the last.
