AI storage stocks: who stores what AI produces
The NAND flash makers, hard drive suppliers, and controller vendors that store AI training and inference data, graded by how direct their exposure is.
Updated · newest price in the table below
The companies
NAND flash makers
Six companies make NAND at scale: Samsung, SK Hynix with Solidigm, Kioxia, Sandisk, Micron, and China's YMTC. Only Sandisk is a US-listed pure play. Samsung, SK Hynix, and Micron run flash as a segment inside a larger memory or electronics business, which is the single most important thing to understand before buying the theme.
| Ticker | Company | Exposure | Why it is here | Price | Day | Market cap | Next earnings | Our coverage |
|---|---|---|---|---|---|---|---|---|
| SNDK | Sandisk Corporation Sandisk does not own the plants that make its NAND. Kioxia owns the Yokkaichi and Kitakami plants, and the two companies co-own the manufacturing equipment through joint ventures, a partnership running more than 25 years, so its capacity decisions are made jointly with a competitor rather than alone. | Direct | The only US-listed pure play in NAND flash and enterprise SSDs, so nothing else in the business dilutes its exposure to flash pricing. | $1150.89 | -13.47% | $163.8B | - | 67 |
| MU | Micron Technology, Inc. Micron is graded Direct on our HBM page. It is the same company on both, weighted differently: high bandwidth memory is what moves it, and flash is the secondary line. | Significant | Makes NAND alongside DRAM, so flash is a real business but a minority of revenue and not what sets the stock's direction. | $884.74 | -5.30% | $1.00T | Dec 23, 2026 | 159 |
| SKHY | SK hynix Inc. SKHY is the US ADR. Ten ADSs equal one Seoul-listed ordinary share, and the ADR has traded at a shifting premium to Seoul since listing, which is a second exposure on top of the company itself. Any company results described on this page belong to the Seoul-listed parent, not to the ADR. | Significant | Owns Solidigm, the former Intel NAND business, on top of its own flash operations, which makes it the number two NAND maker worldwide. Flash still sits behind DRAM and HBM in what drives the company. | $149.21 | -7.95% | $1.05T | Jan 27, 2027 | 126 |
| 005930 | Samsung Electronics Seoul listed, no US exchange listing | Significant | The largest NAND maker in the world, and also a maker of DRAM, HBM, smartphones, and other electronics. No US exchange listing, so it carries no price here, but omitting it would misstate who controls flash supply. | - | - | - | - | Profile |
| 285A | Kioxia Tokyo listed, no US exchange listing | Direct | The former Toshiba Memory, and the only other listed pure-play NAND manufacturer besides Sandisk. It makes flash and nothing else, which makes it the closest international comparable for Sandisk, its partner in the shared Yokkaichi and Kitakami fabs. | - | - | - | - | Profile |
Nearline hard drives
Spinning disk did not die. It became the archive tier, holding the data that is too large for flash and too valuable to delete. Three companies still make hard drives: Seagate, Western Digital, and Japan's Toshiba. Seagate and Western Digital are the two US-listed ones.
| Ticker | Company | Exposure | Why it is here | Price | Day | Market cap | Next earnings | Our coverage |
|---|---|---|---|---|---|---|---|---|
| STX | Seagate Technology Holdings PLC | Direct | One of the two US-listed nearline hard drive suppliers, competing on areal density to keep the cost-per-terabyte gap against flash open. | $644.58 | -7.98% | $148.0B | Jan 26, 2027 | 21 |
| WDC | Western Digital Corporation | Direct | The other US-listed nearline supplier. Since separating from its flash business it is a hard drive company, so it is a cleaner read on disk demand than it used to be. | $366.11 | -7.41% | $137.0B | Jan 28, 2027 | 35 |
Controllers and interface silicon
Raw flash is not a drive. Controllers handle wear levelling, error correction, and the interface, and they are where a merchant vendor can sell into every flash maker at once.
| Ticker | Company | Exposure | Why it is here | Price | Day | Market cap | Next earnings | Our coverage |
|---|---|---|---|---|---|---|---|---|
| SIMO | SIMO | Significant | Silicon Motion calls itself the global leader in supplying NAND flash controllers for solid state storage devices, and it sells to flash makers and module houses rather than competing with them. Exposed to flash volumes rather than flash prices, which is a meaningfully different cycle. | - | - | - | - | 0 |
Equipment
Adding flash bits means etching deeper stacks, not just more wafers, which concentrates spending in a narrower set of tools than a logic fab needs.
Exposure grades are our own judgment, defined in the methodology below. Market cap is unavailable from our quote source for a small number of symbols and is left blank rather than estimated. “Our coverage” is the number of articles we have published on that company.
AI storage is the layer below the accelerator. High bandwidth memory feeds the processor for the microseconds a calculation takes, but the training sets going in, the checkpoints written during a run, and the outputs coming out all have to live somewhere cheaper and far larger. That job splits between NAND flash, which is fast and expensive, and nearline hard drives, which are slow and cheap. An AI data center buys both, in quantities set by how much data the models consume and produce.
Who leads
TrendForce ranks the top five NAND brands by NAND revenue. Shares below are for the second quarter of 2026, the latest TrendForce release. TrendForce's top five does not include China's YMTC; Counterpoint Research, using its own estimates, ranked YMTC fifth by second-quarter NAND revenue, behind Micron and Kioxia.
| Company | How to buy it | Position in the market |
|---|---|---|
| Samsung Electronics | Seoul (005930) | The largest NAND maker, at 29.3% of NAND revenue in the second quarter of 2026, according to TrendForce. |
| SK Hynix | US ADR (SKHY), Seoul (000660) | Second, counting Solidigm. One of two makers, with Samsung, that rank among the HBM leaders and in the top two in flash, which makes its capital allocation between the two a live question every quarter. |
| Micron | US (MU) | Third in the second quarter of 2026, ahead of Kioxia. Flash is a minority of a company driven by DRAM and HBM, which is why Micron is graded Significant here and Direct on our HBM page. |
| Kioxia | Tokyo (285A) | Fourth at 13.6% in the second quarter of 2026, and pure-play flash. Listed on the Tokyo Stock Exchange in December 2024. BCPE Pangea Cayman2, a Bain Capital vehicle, has been the largest shareholder since August 3, 2026, with 14.19% of voting rights. Toshiba, the former parent, has been selling down its stake. |
| Sandisk | US (SNDK) | The US-listed pure play, and Kioxia's fab partner rather than purely its rival. The two co-own the manufacturing equipment in Kioxia's Yokkaichi and Kitakami plants through joint ventures, so they compete on product and cooperate on capacity. |
| Seagate and Western Digital | US (STX, WDC) | Not NAND makers at all, and the reason this page has two halves. They are two of the three remaining hard drive makers, with Japan's Toshiba the third, which makes the archive tier far more concentrated than flash. |
What drives this group
The variables that decide whether these companies have a good year. Mechanisms rather than forecasts.
1. The supply cycle, not the demand story
NAND is a commodity made by six companies, and pricing turns on whether they are collectively adding capacity or withholding it.
Why it matters: Storage demand from AI is real, but supply has historically mattered more to these stocks. Flash prices are set at the margin by supply discipline, and the industry has broken that discipline repeatedly. A bullish AI thesis that ignores what the six makers are doing with capacity has skipped the variable that actually moves the group.
2. Checkpoints and inference exhaust
Training runs write model state to disk continuously, and inference at scale produces logs, caches, and generated media that get retained rather than discarded.
Why it matters: This is the mechanism by which AI turns into storage demand, and it is a stock rather than a flow: data written during a run keeps occupying capacity afterward.
3. Flash against disk on cost per terabyte
Every year flash gets cheaper per terabyte and every year hard drives get denser, and the two curves decide how much of the archive tier stays on disk.
Why it matters: The substitution argument has been made for a decade and disk has kept its cost advantage at the capacity end. If that changes, it does not dent hard drive demand gradually, it redirects a whole tier of spending. It is a major structural risk to the drive names and a major opportunity for the flash names.
4. Shared fabs and joint capacity
Two of the six NAND makers manufacture through joint ventures they co-own with a competitor, and capacity decisions there are made jointly.
Why it matters: It means supply response is slower and more negotiated than in an industry where each maker controls its own fabs. It also means a corporate event at one partner, a sale, a listing, or a restructuring, becomes a supply question for the other, which is why ownership changes in flash move more than one stock.
5. Enterprise mix against consumer
The same fabs serve phones, PCs, and data centers, and enterprise SSDs carry different margins from consumer parts.
Why it matters: A maker shifting output toward enterprise can improve margins without any change in flash prices, and a consumer recovery can absorb capacity that the AI story was counting on. Mix is why two flash makers can report opposite results in the same pricing environment.
Our recent coverage
- Sandisk (SNDK) announces 8-for-1 stock split as quarterly results beat forecasts Oct 29, 2026
- AI chipmaker Tenstorrent raises $1.5 billion at a $6.2 billion valuation, with Sandisk (SNDK) among backers Oct 19, 2026
- Memory stocks compared: Micron (MU) vs SK Hynix (SKHY) vs Samsung vs Sandisk (SNDK) vs Kioxia Sep 23, 2026
- Who makes NAND flash? The five big makers, and why China is pushing in Sep 19, 2026
- SK Hynix (SKHY) unit Solidigm is weighing its first US memory plant, with New York in the lead Sep 18, 2026
- SK Hynix's (SKHY) Solidigm weighs an IPO that could value it at up to $150 billion Sep 25, 2026
- Micron (MU) is down nearly 15% on fears of a 2029 memory glut. Chip suppliers report shortages now. Oct 24, 2026
- Lam Research (LRCX) falls 12% after supply warning as chip stocks suffer worst day since June Oct 22, 2026
How the group traded
Unweighted average of the 6 constituents that returned a quote in the most recent session. This is a read on how the group traded, not an index and not a tracked return series.
How this list is built
This is a different group from the memory makers on our HBM page, and it behaves differently. HBM is a three-company oligopoly selling into a supply-constrained boom. Storage is an older, more cyclical industry that spent years in oversupply and is only now being pulled into the AI buildout, which is why the same names can look like value and momentum in the same quarter.
A company is on this page when storing data is the business, not a feature of it, in one of four roles. We grade how direct that exposure is rather than presenting every name as an AI pure play, because storage demand still comes overwhelmingly from phones, PCs, and conventional servers.
- NAND flash makers: companies that manufacture and sell flash memory and the enterprise SSDs built from it.
- Hard drives: companies making the high-capacity nearline disks that hold data too large or too cold for flash.
- Controllers and interface silicon: companies selling the chips that turn raw flash into a usable drive.
- Equipment: companies selling the tools that flash fabs specifically require.
Exposure grades
- Direct. The theme is a primary revenue driver. A change in it changes this company's year.
- Significant. Named by the company as a real driver, but a minority of revenue.
- Indirect. Benefits from the theme inside a diversified business. Do not read it as a pure play.
What is deliberately not here
- High bandwidth memory makers are covered on our HBM page instead. Micron and SK Hynix appear here for their flash businesses only, at a lower grade than they carry there.
- Cloud storage providers and software vendors are demand-side or a different business entirely. This page is about the physical media.
- Diversified equipment makers are included only at an Indirect grade. Flash is real for them and named on their calls, but it sits inside a much larger business.
Prices, market caps and earnings dates come from our market data provider and refresh through the trading day. Filings come straight from SEC EDGAR. Membership and exposure grades are reviewed by us as companies change what they disclose, and changes are recorded in the page history.
Use this data
Our figures are free to reuse in articles, newsletters, and research with attribution and a link back to this page. How every number is computed: methodology. Current table as a file: download CSV.
Suggested citation: AIStockWire, “AI storage stocks,” aistockwire.com/sectors/ai-storage. Questions about the data: support@aistockwire.com.
Related: HBM memory stocks · AI data center stocks · AI infrastructure backlog tracker · Sandisk (SNDK) company page
Frequently asked questions
What are AI storage stocks?
AI storage stocks are the companies that make the media holding AI training data, model checkpoints, and inference output: NAND flash makers and the enterprise SSDs built from their flash, nearline hard drive suppliers that hold the colder archive tier, and the controller vendors that turn raw flash into a usable drive. They are a separate group from the high bandwidth memory makers that feed the accelerator itself.
Is AI storage the same as HBM?
No. High bandwidth memory sits in the accelerator package and feeds the processor during a calculation, measured in gigabytes and priced accordingly. Storage holds the data before and after, measured in petabytes and bought on cost per terabyte. They are different products, different customers inside the same building, and different industry structures: HBM is a three-company oligopoly in shortage, NAND is a six-company commodity industry with a long history of oversupply.
Which stocks are pure plays on NAND flash?
Only two are publicly listed, and one of them is US-listed. Sandisk makes flash and enterprise SSDs and nothing else, and Kioxia, the former Toshiba Memory, is the Tokyo-listed equivalent. China's YMTC is also a pure play but is not listed. Samsung, SK Hynix, and Micron run flash inside larger memory or electronics businesses where something else sets the direction of the stock.
Do hard drives still matter for AI?
Yes, because cost per terabyte still decides where cold data lives. Nearline hard drives hold the archive tier that is too large for flash and too valuable to delete, and flash has not closed the cost gap at the high-capacity end despite a decade of predictions that it would. Seagate, Western Digital, and Toshiba are the three remaining hard drive makers, and the first two are the US-listed ones.
Why do Sandisk and Kioxia share factories?
Because the partnership predates the AI era by more than two decades. Their NAND is made at Kioxia's Yokkaichi and Kitakami plants in Japan using equipment the two companies co-own through joint ventures, so they compete on finished products while jointly owning the equipment that makes them. It means neither can expand or cut flash supply unilaterally, and it is why a corporate event at one of them becomes a supply question for the other.
Why is Micron graded lower here than on the HBM page?
Because the grades describe exposure, not quality. Micron makes NAND and it is a real business, but high bandwidth memory and DRAM are what move the stock, so flash is a minority driver. On the HBM page the same company is graded Direct for the opposite reason. Reading either grade as a view on the company rather than on the theme would be a mistake.
Published for information only. Nothing here is investment advice or a recommendation to buy or sell any security, and membership of this list is not an endorsement of any company on it.