The memory trade gives back: 20% to 40% off the peak tests the pricing-power story
Micron, Sandisk, Seagate and Western Digital ran 500% to 900% and more since the start of 2025. The recent reversal is the first real market test of the thesis behind it.
The Investor · Invest desk

What happened
- Micron, Sandisk, Seagate and Western Digital all rank among the S&P 500's 10 best performers this year, fuelled by demand for memory and storage supporting AI data centre buildout.
- Year to date, Sandisk is up roughly 575%, Micron 240%, Seagate about 210%, and Western Digital more than 170%.
- Since the start of 2025, Micron has surged roughly 920%, Western Digital is up 820% and Seagate nearly 740%, compared with a 25% gain for the S&P 500.
- Sandisk began trading independently in February 2025 and has soared more than 4,300%.
- The group's run began as hyperscalers accelerated spending on AI data centres; supply could not keep pace, creating shortages that gave producers tremendous pricing power and helped propel earnings and stocks higher.
Why it matters
Four memory and storage stocks that sit among the S&P 500's ten best performers this year have handed back a large slice of the move, trading roughly 20% to 40% below their late-June peaks after a sharp reversal in recent weeks [1][6]. That matters because the run rested on a single claim, that AI demand has pulled memory out of its commodity pricing cycle, and the drawdown is the first serious test of it [5][15].
The scale first. Since the start of 2025, Micron is up roughly 920%, Western Digital 820% and Seagate nearly 740%, against 25% for the S&P 500 [3]. Micron's gain is about 37 times the index's over the same stretch [17]. Sandisk, which began trading independently in February 2025, is up more than 4,300% [4]. Year to date the same names are up roughly 575% (Sandisk), 240% (Micron), 210% (Seagate) and more than 170% (Western Digital) [2].
Put those two sets of numbers together and the picture changes. Micron's 920% since the start of 2025 and 240% so far this year imply about 200% in 2025 alone, meaning more of the compounding happened in 2026 than in the year before it [18]. Western Digital works out to roughly 240% in 2025 [19]. Sandisk's move from its February 2025 debut through the end of that year comes to about 550% [20]. This is not a slow re-rating. The steepest part of the move is the most recent part, which is also the part now unwinding, and CNBC dated the peaks to late June with the reversal in the weeks before its August 21 piece [6][7].
The mechanism was straightforward: hyperscalers accelerated AI data centre spending, supply could not keep pace, and the resulting shortages handed producers pricing power that carried through to earnings and then to the stocks [5]. Nothing in that chain is permanent by construction. The bull case is that the demand is structural across the whole stack rather than concentrated in one product. D.A. Davidson's Gil Luria told CNBC that DRAM, NAND and hard drives are not substitutes and that data centres "need all of them," because "they do different things" [9]. Micron chief executive Sanjay Mehrotra made the same point, describing a hierarchy running from high-bandwidth memory through DRAM to SSDs [10], and argued that "the value of memory, that equation has totally changed" [13]. Luria went further, saying memory is "the guts of the model now" rather than a periphery [14].
The counterweight sits in the same reporting. Memory has historically been treated as a commodity, with Micron, SK Hynix and Samsung competing largely on price, which produced the brutal boom-and-bust cycles the industry is known for [15]. Three suppliers competing on price is what the structure was before AI, and the structure has not changed; the demand has.
The differentiation is worth holding onto. DRAM, the fastest and most expensive tier, is Micron's core and the substrate that gets stacked into high-bandwidth memory, which Luria calls more important to the data centre than CPUs [8][12]. NAND is Sandisk's sole focus and part of Micron's mix; hard drives from Seagate and Western Digital are the cheapest way to hold bulk data [8]. Those are different cost curves and different competitive sets, and they have been trading as one basket.
Recovering the highs is arithmetic, not narrative: a name 40% off its peak needs a 67% gain to get back, and one 20% off needs 25% [21].
Clarity's read
What the record supports and how the coverage leans. The claims behind it follow.
Reality
- Evidence52
- Adoption74
- Hype gap+24
- Incentives71
- Confidence55
Claim ledger
Ranked by verification strength, evidence, and original report placement.
- [1]
Micron, Sandisk, Seagate and Western Digital all rank among the S&P 500's 10 best performers this year, fuelled by demand for memory and storage supporting AI data centre buildout.
- [2]
Year to date, Sandisk is up roughly 575%, Micron 240%, Seagate about 210%, and Western Digital more than 170%.
- [3]
Since the start of 2025, Micron has surged roughly 920%, Western Digital is up 820% and Seagate nearly 740%, compared with a 25% gain for the S&P 500.
- [4]
Sandisk began trading independently in February 2025 and has soared more than 4,300%.
- [5]
The group's run began as hyperscalers accelerated spending on AI data centres; supply could not keep pace, creating shortages that gave producers tremendous pricing power and helped propel earnings and stocks higher.
- [6]
Momentum intensified into 2026 before reversing sharply in recent weeks, leaving the four stocks roughly 20% to 40% below their late-June peaks.
- [7]
The CNBC article carrying these figures is dated August 21, 2026.
- [8]
The three main technologies trade off speed against cost: DRAM is the fastest and most expensive and is Micron's bread and butter; NAND flash is slightly slower and cheaper, is Sandisk's sole focus and part of Micron's business; hard disk drives made by Seagate and Western Digital have slower access but are the cheapest way to store huge amounts of data.
- [9]
The technologies are not necessarily substitutes; D.A. Davidson analyst Gil Luria told CNBC that modern computers and data centres "need all of them" and that "they do different things."
- [10]
Micron CEO Sanjay Mehrotra said AI is driving a whole hierarchy of memory requirements, from high-bandwidth memory to DRAM to SSDs.
- [11]
Mehrotra appeared with Jim Cramer from the site of Micron's planned $10 billion research facility in Boise, Idaho.
- [12]
DRAM is the chip stacked to make high-bandwidth memory, which rapidly moves data to and from GPUs and CPUs; Luria said HBM is "more important to the data center than CPUs are."
- [13]
Mehrotra said "Today there is no AI without memory" and that "the value of memory, that equation has totally changed."
- [14]
Luria said memory is "no longer just storage" but "the guts of the model now," not a periphery or an accessory.
- [15]
Memory has historically been considered a commodity: Micron, SK Hynix and Samsung Electronics, the world's three major DRAM producers, competed largely on price, contributing to the brutal boom-and-bust cycles that have long characterised the industry.
- [16]
Micron is the only one of the four that the CNBC Investing Club owns in its portfolio.
- [17]
Micron's gain since the start of 2025 is roughly 37 times the S&P 500's over the same period.
- [18]
Micron's 920% gain since the start of 2025 and 240% year-to-date gain imply a gain of about 200% during 2025 alone, so the 2026 portion of the run is the larger multiple.
- [19]
Western Digital's 820% gain since the start of 2025 and more-than-170% year-to-date gain imply roughly 240% during 2025.
- [20]
Sandisk's more-than-4,300% gain since its February 2025 debut and 575% year-to-date gain imply roughly 550% from February 2025 through the end of that year.
- [21]
A stock trading 40% below its peak needs a 67% gain to regain it; one 20% below needs 25%.
Get this ledger inside ChatGPT. Ask about any of our stories and the answer brings its figure, each claim’s verdict and the sources. Free, no account.
Sources
1 independent publisher whose own reporting we read for this story.
- cnbc.com4 memory stocks are darlings of the AI boom. How they differ and why we own Micron
1 article · August 21, 2026
Topics and entities
Follow any of these and your For You feed starts watching them — no settings page required.
Topics
- AI memory and storageFollow
- Semiconductor CyclicalityFollow
- AI Data Center BuildoutFollow
- AI trade drawdownFollow