Key points
- Kioxia is the former Toshiba Memory. It makes NAND flash only, no DRAM and no HBM, and held 14% of the NAND market in Q1 2026.
- No single shareholder controls it. Toshiba is the biggest holder left at 15.10%, and it's still selling. An SK Hynix (SKHY) vehicle holds 14% in unconverted bonds.
- Bain Capital sold its last Kioxia shares in July 2026, taking about 2.5 trillion yen out of the position. Nikkei called it a record for Japan.
- Sandisk (SNDK) co-owns the plants that make the chips. No US listing yet: KXIAY and KXHCF trade over the counter.
Kioxia Holdings makes NAND flash memory, the storage inside solid state drives, and nothing else. It was part of Toshiba until 2018. No single shareholder controls it today.
The private equity firm Bain Capital led the buyout that took the memory business out of Toshiba, and it sold the last of that stake in July 2026. Bain took about 2.5 trillion yen out of the position. Nikkei put the figure at $17 billion and called it a record for Japan.
The two names closest to the top of the register now are a company that used to own all of it and a Korean competitor that can't vote its shares yet.
Who owns Kioxia now?
The largest disclosed holder is Toshiba, at 15.10% as of July 15, 2026. That figure has fallen every few weeks this year, from 18.52% in January to 17.62% in March and 16.10% in May.
| Holder | Stake | Detail |
|---|---|---|
| Toshiba | 15.10% | As of July 15, 2026. Selling down in steps. |
| SK Hynix (SKHY) vehicle | 14% | Convertible bonds, not yet converted to voting stock. |
| Bain Capital | 0% | Fully exited July 2026, from about 44% in December 2025. |
SK Hynix put money into the 2018 deal two ways. It bought 129 billion yen of convertible bonds, the piece behind the 14% figure, and it committed another 266 billion yen to the Bain fund as a limited partner. Its second quarter results booked gains from the fund's sale and from a revaluation of the bonds. The bonds themselves have not been sold.
The SK Hynix position sits in a special purpose vehicle and hasn't been converted into common stock. To vote those shares, SK Hynix would need antitrust clearance in several countries. Korean financial press has described it as the effective second largest shareholder rather than the registered one.
Toshiba booked 2.28 trillion yen (about $14.5 billion) in gains on Kioxia share sales and revaluation in the fiscal year ended March 2026.
How did Toshiba end up selling it?
Toshiba invented NAND flash. Fujio Masuoka's team at the company developed it in the 1980s. The sale came out of an accounting disaster somewhere else entirely.
- 2017: Losses at Toshiba's Westinghouse nuclear construction unit force the sale of the memory business.
- June 1, 2018: Toshiba Memory closes into K.K. Pangea, a vehicle controlled by a Bain-led consortium, at about $18 billion. Bain's group takes 49.9% of voting rights, Toshiba keeps 40.2%, Hoya takes 9.9%.
- October 1, 2019: Renamed Kioxia, from the Japanese kioku for memory and the Greek axia for value.
- December 2023: Toshiba itself goes private under Japan Industrial Partners in a deal near $14 billion, ending 74 years as a listed company.
- December 2024: Kioxia lists on the Tokyo Stock Exchange at 1,455 yen a share.
Apple (AAPL), Dell (DELL), Seagate (STX) and Kingston also put money into the 2018 deal, through preferred stock carrying no vote and no role in governance. They were buying supply, not control. SK Hynix agreed at the time to hold under 15% of the voting rights for ten years.
What kind of memory does Kioxia make?
NAND flash, and nothing else. Kioxia doesn't make DRAM and doesn't make the high bandwidth memory that sits next to an AI accelerator. That separates it from Samsung, SK Hynix and Micron (MU), which all run both businesses.
NAND is the memory inside solid state drives. It holds data when the power is off. Kioxia ranked third in that market in the first quarter of 2026, a point ahead of three rivals tied at 13%, including China's YMTC.
| NAND maker | Q1 2026 share |
|---|---|
| Samsung | 29% |
| SK Hynix (SKHY) | 18% |
| Kioxia | 14% |
| Micron (MU) | 13% |
| Sandisk (SNDK) | 13% |
| YMTC | 13% |
The product line is called BiCS. Kioxia and Sandisk began sample shipments of the tenth generation on July 3, 2026.
| Generation | Layers | Status |
|---|---|---|
| BiCS8 | 218 | Current volume production |
| BiCS10 | 332 | Sampling since July 3, 2026. Mass production targeted for 2027. |
BiCS10 is a 1 terabit part with bit density above 29 gigabits per square millimeter and an interface speed of 4.8 gigabits per second. Kioxia says that's 59% denser than BiCS8. Some of the gain is the extra layers. The rest is CBA, short for CMOS directly Bonded to Array. CBA bonds the control logic straight onto the memory array instead of placing it alongside.
Samsung has announced NAND above 400 layers. Kioxia says its 332-layer design still reaches higher bit density, at about 10% lower cost per gigabyte and 10% better power efficiency.
Why does Sandisk move with Kioxia?
Because they own the factories together. The Yokkaichi and Kitakami plants that make Kioxia's NAND are joint ventures with Sandisk, and the partnership goes back more than 25 years.
On January 29, 2026, the two extended the Yokkaichi agreement from the end of 2029 to December 31, 2034. The Kitakami agreement runs to the same date. Sandisk agreed to pay Kioxia $1.165 billion for manufacturing services and continued supply, in installments running from 2026 through 2029. When Kioxia closed limit-down in Tokyo on July 28, Sandisk closed down 14.25% in New York the same day.
What did Kioxia report on July 31?
Records on the top line and a miss against consensus underneath, depending on which profit figure you use.
| Q1 FY2026 | Yen | USD |
|---|---|---|
| Revenue | 1,767.1 billion yen | $11.2 billion, up 415.5% from a year earlier |
| Non-GAAP operating profit | 1,326.2 billion yen | $8.4 billion, a 75% margin |
| Operating income vs consensus | 1.27 trillion yen | $8.1 billion, against 1.37 trillion expected |
| Non-GAAP net income | 887.0 billion yen | $5.6 billion |
| Q2 revenue guidance | 2,390 billion yen | $15.2 billion, up 35.2% |
| Q2 operating profit guidance | 1,900 billion yen | $12.1 billion, up 48.8% |
Blended selling prices rose 70% from the prior quarter. Bit volume grew low single digits. Goldman Sachs had expected operating profit of 1.417 trillion yen (near $9.0 billion).
Kioxia repaid 407.5 billion yen (about $2.6 billion) of senior loans. It finished the quarter in a net cash position, with the equity ratio at 51% against 38%.
The board authorized a buyback of up to 30 million shares for 800 billion yen (some $5.1 billion), or 5.47% of the shares outstanding. It runs to October 30, 2026. A 3-for-1 stock split takes effect October 1.
Both had been signalled a month earlier. "We are considering a stock split so that more investors can hold shares, and we expect to be able to announce it soon," Vice President Yoshihiko Kawamura told the Seoul Economic Daily in June. The company would "expand shareholder returns more aggressively," he added.
Ikuo Mitsui, a fund manager at Aizawa Securities, said ahead of the report that "a buyback could send a signal that management views the stock as oversold."
Tokyo closed at 46,500 yen ($295), up 7,000 yen or 17.72%. Results were scheduled for 15:30, the same time as the close. The two US traded lines took the reaction instead. The ADR, KXIAY, closed down 10.10% at $27.80, and KXHCF fell 7.98% to $282.49.
How far has the stock moved?
It listed at 1,455 yen in December 2024. On June 12, 2026 it passed Toyota to become Japan's most valuable listed company, ending a run Toyota had held for 22 years. Ten days later it peaked at 112,700 yen ($716).
Then it fell as far as 66% below that high, bottoming at 38,380 yen on July 29. It went limit-down twice in July. Friday's rebound left it 59% under the peak, a loss of about $230 billion in market value. Even after that drop it's up 346% for 2026 so far. Market value at the July 31 close was 25.48 trillion yen (near $162 billion).
The selling wasn't tied to Kioxia news. ChangXin Memory's Shanghai debut on July 27 raised about $8.6 billion and closed up 466%. Memory names sold off across Asia and the United States that week. SK Hynix missed consensus two days later.
Can US investors buy Kioxia?
Not on a US exchange. Kioxia trades in Tokyo under 285A, and three routes reach it from a US brokerage account.
| Route | Ticker | July 31 close |
|---|---|---|
| Tokyo, direct | 285A | 46,500 yen ($295) |
| Unsponsored ADR, over the counter | KXIAY | $27.80 |
| Ordinary shares, over the counter | KXHCF | $282.49 |
Buying in Tokyo costs the most to start. Shares there trade only in blocks of 100, a unit called a board lot. At Friday's close one Kioxia lot ran 4.65 million yen, about $29,500. Kioxia carried the most expensive board lot on the entire exchange as of June 30, at 8.97 million yen, near $57,000.
The Tokyo Stock Exchange asked 270 companies in 2026 to bring their entry costs down, and treats 500,000 yen as the level a board lot should stay under. Kioxia's 3-for-1 split on October 1 cuts its lot to about 1.55 million yen, near $9,850 at Friday's price. The company said the split is meant to lower the amount needed to buy in and widen the shareholder base.
Interactive Brokers (IBKR) is one of the few US brokers offering direct access to the Tokyo exchange. It charges 0.08% of trade value on Japanese stocks, with a minimum of 80 yen.
The two over the counter lines skip that. An ADR, or American Depositary Receipt, is a US traded certificate representing shares held at a bank overseas. KXIAY is unsponsored, meaning Kioxia had no hand in setting it up. JPMorgan Chase Bank is the depositary.
Each KXIAY share represents one tenth of an ordinary share. It traded 4.4 million shares on Friday, against a three-month average near 2.2 million. KXHCF is one for one with the Tokyo shares and trades far less. Its three-month average is under 18,000 shares a day, and on July 24 it traded 262.
Support for over the counter securities varies by broker, and some retail platforms don't carry them at all, so the symbol has to be checked account by account.
Dividends are close to a non-issue for now. Kioxia plans to start a progressive dividend in the fiscal year ending March 2027. Japan withholds 15.315% on dividends from listed shares, and the US treaty rate for portfolio investors is 10%, according to PwC's tax summaries.
Kioxia said in May 2026 that it plans to list American Depositary Shares in the United States. Korean press reported the target window as April to May 2027. The exchange, the timing and the size are all unset, and Kioxia has said it could drop the plan.
Kioxia's memory business managing director, Shunsuke Nakato, said earlier this year that the company's 2026 production is already sold out. The tightness runs into 2027, he said, because so many companies keep investing in AI rather than be left behind.
President Hiroo Ota took over on April 1, after 41 years at the company. "Long-term contracts with U.S. hyperscalers are increasing," he told the Seoul Economic Daily in June. "As data processing volumes surge with the spread of agentic AI and physical AI, memory demand will grow another notch, and the current strong demand is not a temporary phenomenon."
Prices are Friday, July 31, 2026 Tokyo closes. Yen figures converted at 157.40 yen to the dollar. Nothing here is investment advice.
