The S&P 500 Fell, but These 2 AI Memory Stocks Exploded Higher

The S&P 500 Fell, but These 2 AI Memory Stocks Exploded Higher

Sat, September 5, 2026 at 10:03 PM GMT+3 3 min read

Wall Street delivered a sharp split on September 4. The S&P 500 fell 0.4% after a stronger-than-expected jobs report lifted rate concerns, but Sandisk jumped 11.9% and Micron gained 6.1%. The divergence matters because it was not a broad risk-on move. The pattern was consistent with investors rotating toward memory and storage suppliers that help keep AI systems fed with data. That put Sandisk Corporation (NASDAQ:SNDK) and Micron Technology, Inc. (NASDAQ:MU) at the center of the session.

Source: Sandisk Corporation

Sandisk offers the purer NAND and flash-storage argument. Its August results established data center as a key growth pillar, and management said it had signed five more new-business-model agreements since April. The bull case is that AI expands high-value enterprise storage demand while tighter supply supports pricing. The bear case is cyclicality: customer agreements cannot eliminate inventory swings, pricing reversals, or the execution risk that comes with a newly independent public company.

Professional ownership broadened before Friday's rally. Insider Monkey counted 128 hedge funds holding Sandisk Corporation (NASDAQ:SNDK) at June 30, up from 114 at March 31. Leopold Aschenbrenner's Situational Awareness LP disclosed 2,495,344 shares, about 119% more than the 1,140,119 shares reported in Q1. Those filings are quarter-end snapshots and do not show what the funds did during the September move.

Micron supplies both high-bandwidth memory and conventional DRAM and NAND. Its fiscal third-quarter revenue reached $41.46 billion, while Cloud Memory revenue rose to $13.77 billion and Core Data Center revenue to $11.52 billion. That operating leverage is the bull case. The counterargument is that extraordinary margins invite capacity additions, and today's scarcity economics may normalize faster than investors expect.

Hedge-fund breadth also rose for Micron Technology, Inc. (NASDAQ:MU), to 184 funds in Q2 from 154 in Q1. Cliff Asness's AQR Capital Management reported 3,833,728 shares, about 15% fewer than the 4,523,415 shares disclosed in Q1. The August 14 exchange-reported settlement recorded 7,676,558 SNDK shares sold short, about 8.24% of the estimated public float, equal to roughly 0.5 day of average trading volume. That snapshot predates the rally and cannot identify motive.

The session supports a real thesis: AI demand is spreading from accelerators into the memory hierarchy. Sandisk has more focused upside but greater company-specific and NAND-cycle risk. Micron has broader product exposure and exceptionally strong disclosed margins, yet it also carries more expectations. The next proof points are pricing, data-center mix, and whether customer commitments survive the next supply response. Both can benefit from demand while suffering very different supply and execution failures, a distinction Friday's prices cannot resolve. Quarterly contract volumes should reveal which thesis is gaining ground.

While we acknowledge the potential of SNDK and MU as investments, we believe certain other AI stocks offer greater upside potential and carry less downside risk. If you're looking for an extremely undervalued AI stock that also stands to benefit significantly from Trump-era tariffs and the onshoring trend, see our free report on the best short-term AI stock.

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