Behind KIOXIA's sevenfold growth in one year, surpassing Toyota to become Japan's largest shareholder, there is also a most dedicated and steadfast major investor.

In 2018, Bain Capital led a consortium to acquire the storage chip manufacturer Kioxia (formerly Toshiba Memory) for about $18 billion.
2018–2020: From Toshiba Memory to "Kioxia"
After the acquisition was completed, it officially renamed to "Kioxia" in 2019, completing brand and corporate independence.
Toshiba retained about 40% of the shares, while Bain-led consortium held approximately 56%, forming a dual-major shareholder structure of "Bain Consortium + Toshiba," with plans to exit via IPO in the future.
2020–2023: Repeated IPO delays and acquisition setbacks
Kioxia originally planned to IPO in Tokyo in 2020, but due to the downturn in the NAND cycle combined with a slowdown in the semiconductor market, valuation was not ideal, and market volatility forced the IPO to be postponed.
Later, Bain also attempted to push for a merger with Western Digital (WDC), but due to resistance from shareholders like SK Hynix and regulatory hurdles, the deal was ultimately vetoed, and the exit path was once again stalled.
2024: IPO despite low valuation, aiming to go ashore first
Bain restarted Kioxia's IPO process, initially aiming for a market cap of about 1.5 trillion yen, but faced "bargaining" from the market.
Ultimately, Kioxia listed on the Tokyo Stock Exchange Prime Market on December 18, 2024, with an offering price guide of approximately 1,390–1,520 yen, corresponding to a market cap of about 750–784 billion yen, significantly lower than the overall enterprise value at the time of the 2018 acquisition, and also below the higher valuation plans Bain had previously attempted to promote.
After 2024: AI cycle drives NAND reversal
With the explosion of generative AI, data center expansion, and high-performance storage demand, NAND prices began to rebound sharply from lows in the second half of 2024.
Market expectations for Kioxia's profit recovery and medium- to long-term growth significantly improved, driving the stock price to continue rising since the IPO.
2025–2026: Large-scale divestments and "cash-out window"
Due to the stock price rising sharply within about a year of the IPO, Bain Capital began selling Kioxia shares to overseas institutional investors through block trades.
In November 2025, approximately 36 million shares were sold, with a transaction amount of about 355 billion yen (roughly $2.3 billion).
In February 2026, Bain again sold Kioxia shares worth about $3.5 billion, further cashing out significantly and reducing its stake, but remaining one of the major shareholders.