AI storage stocks: who stores what AI produces
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.
Updated · newest price in the table below
The companies
NAND flash makers
Five companies manufacture NAND at scale, and only one of them is a US-listed pure play. Everything else in flash is 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 its fabs outright. The Yokkaichi and Kitakami plants that make its NAND are joint ventures with Kioxia, 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. Nothing dilutes the exposure, which makes it the cleanest read on flash pricing and also the most violent way to hold it. | $1519.97 | -0.71% | $222.6B | Nov 6, 2026 | 57 |
| 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. | $926.55 | -0.11% | $1.05T | Sep 30, 2026 | 131 |
| 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. | $174.87 | +0.02% | $1.24T | Oct 27, 2026 | 111 |
| 005930 | Samsung Electronics Seoul listed, no US ticker | Direct | The largest NAND maker in the world and the price setter for the whole industry. No US listing, so it cannot be bought in a US brokerage account and carries no price here, but omitting it would misstate who controls flash supply. | - | - | - | - | Profile |
| 285A | Kioxia Tokyo listed, no US ticker | Direct | The former Toshiba Memory, and the only other pure-play NAND manufacturer besides Sandisk. It makes flash and nothing else, which makes it the closest international comparable for Sandisk and the reason the two share 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. Two Western suppliers are left at scale, which is a rare structure in any semiconductor-adjacent industry.
| 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 remaining Western nearline suppliers, and the one pushing hardest on areal density to keep the cost-per-terabyte gap against flash open. | $783.18 | +1.47% | $178.1B | Oct 27, 2026 | 21 |
| WDC | Western Digital Corporation | Direct | The other half of the nearline duopoly. 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. | $416.97 | +1.22% | $150.3B | Nov 5, 2026 | 32 |
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 | The largest merchant SSD controller vendor, selling into 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.
| Ticker | Company | Exposure | Why it is here | Price | Day | Market cap | Next earnings | Our coverage |
|---|---|---|---|---|---|---|---|---|
| LRCX | Lam Research Corporation | Indirect | The strongest equipment exposure to NAND specifically, because building taller 3D stacks is an etch and deposition problem. Flash is one end market inside a much larger equipment business. | $269.23 | -0.61% | $336.9B | Oct 21, 2026 | 12 |
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.
Who leads
NAND market share is measured in bits shipped, and the ranking has been more stable than the price of what is being shipped. Shares below are for the first quarter of 2026.
| Company | How to buy it | Position in the market |
|---|---|---|
| Samsung Electronics | Seoul (005930) | The largest NAND maker, at 29% of the market in the first quarter of 2026. Sets industry pricing more than it follows it, and its capacity decisions are the ones the other four react to. |
| SK Hynix | US ADR (SKHY), Seoul (000660) | Second at 18%, counting Solidigm. The only maker that is simultaneously a leader in HBM and a top-two force in flash, which makes its capital allocation between the two a live question every quarter. |
| Kioxia | Tokyo (285A) | Third at 14%, and pure-play flash. Listed on the Tokyo Stock Exchange in December 2024. Toshiba retains 10% and a special purpose vehicle tied to SK Hynix holds 14%, though that stake sits in convertible bonds that have not been converted into voting stock. |
| Sandisk | US (SNDK) | The US-listed pure play, and Kioxia's fab partner rather than purely its rival. The two co-own the plants that make their NAND, 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 the only two Western nearline hard drive suppliers left at scale, which gives the archive tier a duopoly structure that flash does not have. |
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 five companies, and pricing turns on whether they are collectively adding capacity or withholding it.
Why it matters: Storage demand from AI is real, but it has never been what decides the 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 five 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. It is also the part most likely to surprise, because retention policies at AI labs are set by what might be useful later rather than by what is needed now.
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. This is the single largest structural risk to the drive names and the largest structural opportunity for the flash names.
4. Shared fabs and joint capacity
Two of the five NAND makers manufacture in plants 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.
Recent SEC filings
| Filed | Ticker | Form | Company |
|---|---|---|---|
| Sep 16, 2026 | SNDK | 4 | Sandisk Corp — PRIMARY DOCUMENT |
| Sep 16, 2026 | SNDK | 4 | Sandisk Corp — PRIMARY DOCUMENT |
| Sep 16, 2026 | SNDK | 8-K | Sandisk Corp — 8-K |
| Sep 15, 2026 | SNDK | 144 | Sandisk Corp |
| Sep 14, 2026 | SNDK | 144 | Sandisk Corp |
Our recent coverage
- Kioxia weighs $10 billion US ADR deal as SK Hynix (SKHY) stake comes into focus Sep 14, 2026
- Sandisk (SNDK), Dell (DELL), Palo Alto (PANW) and Arista (ANET) join the S&P 100 as Nike exits Sep 5, 2026
- Why SanDisk (SNDK) went from red at 3:15 to up 5.7% at the August 31 close Aug 31, 2026
- AI's storage ladder: HBM, flash and Seagate's (STX) race to the 100TB hard drive Aug 29, 2026
- Kioxia plans a $6.3 billion new memory plant in Japan, Nikkei reports Aug 26, 2026
- Seagate (STX)'s CEO and four other executives sold $43 million in 48 hours. The stock fell 6.5% three days later. Aug 24, 2026
- Memory chip prices are soaring. So why are Micron (MU), SanDisk (SNDK) and SK Hynix (SKHY) falling? Aug 21, 2026
- Taiwan's chip industry has more than two openings per job seeker. The AI buildout needs people. Sep 15, 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, storage is a five-company commodity industry with a long history of oversupply.
Which stocks are pure plays on NAND flash?
Only two in the world, 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. Every other NAND maker, Samsung, SK Hynix and Micron, runs flash inside a larger memory or electronics business 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 and Western Digital are the only two Western suppliers left at scale, so the tier has a duopoly structure.
Why do Sandisk and Kioxia share factories?
Because the partnership predates the AI era by more than two decades. The Yokkaichi and Kitakami plants in Japan that produce their NAND are joint ventures between the two companies, so they compete on finished products while jointly owning the capacity 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.