# Kioxia becomes Japan’s most valuable firm as AI mania goes on > Source: > Published: 2026-06-12 07:43:00+00:00 Memory chipmaker Kioxia Holdings replaced Toyota Motor to become Japan’s largest company by market value, underscoring how the global artificial intelligence boom is reshaping the country’s corporate landscape. Shares of the Japanese memory chipmaker surged 7.6% Friday, lifting its market value above ¥44 trillion ($274 billion) just 18 months after its stock market debut. Automaker Toyota, which earlier briefly lost the top spot to SoftBank Group, closed with a market capitalization of ¥43.8 trillion. The figures include treasury shares. The shift highlights investors’ growing preference for semiconductor companies, as demand for chips used in AI data centers has climbed alongside peers worldwide. Kioxia has surged more than 670% this year, making it the best performer on the MSCI World Index.