Sandisk: The Competitor Kioxia Manufactures ForNarrow moat

Kioxia Holdings (285A) — moat facet

Thirteen percent against fourteen, sourced from jointly owned fabs built on jointly owned technology -- and the shareholder who vetoed the merger that would have ended it has now sold out.

This is the most unusual competitive relationship in the collection and it deserves stating without softening.

The most unusual rivalry in the collectionJointly owned fabsJointly ownedprocesstechnologySandisk sourcessubstantially allits flash thereThen sellsagainst Kioxiaat 13% vs 14%A merger to end this collapsed in October 2023 on SK hynix's veto. SK hynix has now sold out.
The obstacle to consolidation was a shareholder, and the shareholder has left.

Sandisk held about 13% of NAND revenue in the first quarter of 2026 to Kioxia's 14%1. Its own prospectus states that substantially all of its flash memory comes from the joint ventures with Kioxia, and that the two companies co-develop process technology and memory design and jointly own the result2. Seven of Kioxia's nine plants sit inside those ventures, with equal decision-making rights3.

So the second-closest competitor cannot be beaten on cost, cannot be beaten on process, and cannot be starved of supply — because the supply is jointly owned. What separates the two firms is controllers, firmware, drive design, channel and brand: everything above the flash.

The industry has tried to resolve this. A merger of Kioxia with Western Digital's flash business — the business that became Sandisk when it separated in February 2025 — was negotiated for more than two years and collapsed in October 2023, when SK hynix, an investor in Kioxia through the Bain consortium, declined to approve it4. SK hynix has since disposed of that position entirely.

The veto that blocked consolidation is gone. Whether the logic that motivated it survived is the single most consequential open question about this company.

Watch for a renewed approach. The obstacle was a shareholder, and the shareholder has left.

Moat trajectory: Holding steady

The relationship was renewed through 2034 in January 2026, so the awkwardness is fixed in place for eight years. What changed is outside it: the shareholder who vetoed the 2023 merger has sold out.

The number that tests this moat
Third-party estimate
Sandisk's NAND revenue share
13.9% in Q1 2026, tied with Micron

Sandisk sells flash made in the ventures it shares with Kioxia. A rising Sandisk share means Kioxia's partner is winning customers with the same wafers.

Source: TrendForce NAND ranking, Q1 2026 ↗
References
  1. Third-party estimateSandisk held about 13% of NAND revenue in Q1 2026 to Kioxia's 14%.
    Counterpoint Research — global NAND memory market share. The NAND market reached a record US$46 billion in the first quarter of 2026, growing about 90% sequentially and roughly 3.5 times against the first quarter of 2025. Share by revenue: Samsung 29%, SK hynix 18%, Kioxia 14%, Micron 13%, Sandisk 13% and YMTC 13% — YMTC having risen from about 8% a year earlier. — Q1 2026 · publ. 2026 · source ↗
  2. ReportedThe two companies co-develop process technology and memory design and jointly own the result, and substantially all of Sandisk's flash comes from the ventures.
    Sandisk Corporation, Form 424B4 prospectus (SEC, CIK 2023554) — Sandisk and Kioxia operate three business ventures, Flash Partners Ltd., Flash Alliance Ltd. and Flash Forward Ltd. (collectively 'Flash Ventures'), across seven flash-based manufacturing facilities in Japan, six in Yokkaichi and one in Kitakami, with an eighth beginning operations in calendar year 2025. 'We co-develop flash technologies (including process technology and memory design) with Kioxia for Flash Ventures' use. We and Kioxia jointly own these co-developed flash technologies.' 'Substantially all of our flash-based memory is obtained from our joint ventures with Kioxia... While substantially all of our flash memory supply utilized for our products is purchased from these ventures, from time to time, we also purchase flash memory from other flash manufacturers.' Sandisk names Kioxia, Micron, Samsung, SK Hynix and YMTC among its competitors, and completed its separation from Western Digital in February 2025. — FY2025 · publ. 2025-05 · source ↗
  3. ReportedSeven of Kioxia's nine plants sit inside Flash Ventures, with equal decision-making rights.
    Kioxia Holdings Corporation, Annual Securities Report for the year from 1 April 2025 to 31 March 2026 (8th Period) — revenue ¥2,337,628M against ¥1,706,460M, gross profit ¥1,012,904M, operating profit ¥869,013M, profit for the year ¥554,490M; research and development cost ¥141,052M against ¥132,798M; purchases of property, plant and equipment ¥281,062M against ¥223,847M; operating cash flow ¥616,540M; proceeds from government grants ¥56,396M against ¥43,748M, from an approved ceiling of ¥150.0bn for flash production at the Yokkaichi and Kitakami plants with about ¥31.8bn not yet received. Revenue by application: SSD & Storage ¥1,362,638M, Smart Devices ¥759,978M, Other ¥215,012M — 'Other' including retail products and sales to the Sandisk group recorded through the three manufacturing joint ventures. Revenue by geography: Japan ¥263,252M, North America and Europe ¥1,217,643M, Asia ¥856,733M, with the United States ¥1,098,832M, China ¥381,857M and Taiwan ¥300,932M. Non-current assets: Japan ¥1,658,950M, North America and Europe ¥1,986M, Asia ¥6,298M. Major customers: Apple group ¥476,014M (20.4%), with the Sandisk and Dell groups omitted for the year as each fell below 10% of sales. Flash Partners Ltd., Flash Alliance Ltd. and Flash Forward LLC are accounted for as joint operations with 50.1% of the voting rights and equal decision-making rights shared with Sandisk. Net interest-bearing debt ¥552,085M against equity of ¥1,398,929M — a net debt-to-equity ratio of 0.39 times, from ¥931,035M against ¥737,565M and 1.26 times a year earlier; USD-denominated senior notes at 6.25% (2030) and 6.625% (2033); goodwill of ¥395,585M from the 1 June 2018 acquisition of the former Toshiba Memory Corporation. Bain Capital funds indirectly hold 21.87% and Toshiba Corporation 17.59% of outstanding common shares, both having sold substantial holdings during the year. Risk factors state that the Yokkaichi Plant is located in an area with a high risk of earthquakes and floods and the Kitakami Plant in an area severely damaged by the 2011 Tohoku Earthquake, and name US-China trade frictions and US tariff policy among factors that may materially affect the business. The company does not provide plans or progress reports for the overall fiscal year. — year to 31 March 2026 · publ. 2026-06 · source ↗
  4. ReportedThe merger collapsed in October 2023 when SK hynix, an investor through the Bain consortium, declined to approve it.
    TechCrunch — 'Memory chip maker SK Hynix, a shareholder of Kioxia, opposes a merger with Western Digital', 26 October 2023. After more than two years of talks, Western Digital notified Kioxia that the proposed combination of its flash business with Kioxia would not proceed, citing the failure to obtain approval from SK hynix, a significant investor in Kioxia through the Bain Capital-led consortium, which had invested more than US$2.6 billion and objected that the transaction would undervalue its stake. — October 2023 · publ. 2023-10-26 · source ↗
Sources
Generated September 23, 2026