A memory chip maker just overtook Toyota as Japan's most valuable company
Kioxia, the NAND flash memory maker spun out of Toshiba in 2018, briefly overtook Toyota as Japan's most valuable listed company on June 12. Kioxia's market cap hit approximately $240 billion, according to Companies Market Cap, edging past Toyota's $224 billion during intraday trading. The gap closed by end of session, but the milestone stands: a memory chip company is now worth more than the world's largest automaker.
Silicon over steel
Kioxia is not a household name outside the tech industry, but it sits third in the global NAND flash market behind Samsung and SK Hynix, per Counterpoint Research. NAND flash is the storage technology inside every SSD, smartphone, and data-center server. Demand for it has exploded — the overall NAND market grew 90% quarter-over-quarter in Q1 2026, driven almost entirely by AI data-center buildouts from Google, Microsoft, and their peers.
Enterprise SSD prices rose 53–58% in a single quarter early this year, TrendForce reports, a record quarterly jump. Kioxia and its peers have essentially sold out capacity through the end of 2026. That scarcity is what investors are pricing in.
What's driving the valuation
Every large language model needs enormous amounts of fast storage, not just computing power. Each new data center going up requires thousands of enterprise-grade SSDs. Kioxia is one of only a handful of companies capable of producing NAND at industrial scale, which makes it a chokepoint in the AI supply chain — and a very attractive one.
The company is doubling down: it plans to raise capital expenditure by 41% year-over-year to $4.5 billion. Bain Capital holds a 51% stake; Toshiba retains around 30%.
The bigger picture
Toyota, meanwhile, faces margin pressure as semiconductor shortages affect automotive production — the very chips it needs are being reallocated toward AI infrastructure. The irony is sharp. The company that defined Japanese industrial dominance for decades is now competing for factory capacity with the company that briefly outranked it on the stock exchange.
For US cloud providers already locked into expensive, long-lead-time SSD orders, this valuation story reinforces one thing: the AI infrastructure race has made memory chips a strategic asset, not just a commodity.
