✦ Bain and Toshiba on the Way OutNarrow moat

Kioxia Holdings (285A) — the future bets

Nearly forty percent of the company sits with two holders who have already demonstrated they are sellers, in a stock that has halved since June.

The largest single influence on Kioxia's share price over the next two years may have nothing to do with flash.

Kioxia share register, March 2026Bain Capital funds — 22%Toshiba — 18%Everyone else — 61%Both sold heavily during the year; the filing warns further sales may move the price.
Nearly forty percent sits with two holders who have shown they are sellers.

At March 2026, funds advised by Bain Capital indirectly held 21.87% of the company and Toshiba held 17.59% — and the filing notes that both sold substantial numbers of shares during the year, warning that further sales, or the market expecting them, may affect trading and the share price1. Two Bain partners sit on the board and a third on the audit and supervisory board2.

This is the unfinished business of the 2018 carve-out. Bain bought a business it intended to exit; Toshiba retained a stake at the request of Japanese authorities who wanted a domestic anchor shareholder. Neither is a natural long-term owner, and nearly 40% of the company sits with holders who have already demonstrated they are sellers.

The bull case is that the overhang ends. A clean register, a larger free float and index inclusion — Kioxia joined the Nikkei 225 in March 20263 — bring in owners who buy for the business rather than trade around the supply.

The bear case is that the selling continues into a falling market, and the shares are already 53% below their June high.

The number to watch is the two stakes at each reporting date. They are disclosed, they are large, and they are the clearest supply-and-demand fact about this stock.

Moat trajectory: Widening

Both holders sold substantial numbers of shares during the year to March 2026, leaving Bain at 21.87% and Toshiba at 17.59%. Every share they sell moves the register closer to ordinary public ownership.

The number that tests this moat
Reported
Combined Bain and Toshiba holding
39.5% — 21.87% and 17.59% at March 2026

Both sold substantial numbers of shares during the year, and Kioxia's own filing warns that further sales, or the market expecting them, may affect the share price. Nearly forty percent of the company sits with holders who have demonstrated they are sellers. Watch the two stakes at each reporting date.

Source: Kioxia Holdings, Annual Securities Report for the year to 31 March 2026 ↗
References
  1. ReportedBain funds held 21.87% and Toshiba 17.59% at March 2026; both sold substantial holdings during the year, and the filing warns further sales may affect the share price.
    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 ↗
  2. ReportedTwo Bain Capital partners are directors of the company and a third is an Audit and Supervisory Board member.
    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 ↗
  3. ReportedKioxia was added to the Nikkei Stock Average in March 2026.
    Kioxia Holdings — 'Kioxia Holdings Added to the Nikkei Stock Average (Nikkei 225)', 5 March 2026. — March 2026 · publ. 2026-03-05 · source ↗
Sources
Generated September 23, 2026