SemiconductorsAI boom raises memory maker's stock price 56-fold in 18 monthsKioxia's market cap has reached 44 trillion yen ($275 billion) in a year and half since listing. (Nikkei montage/Source photos by Nikkei and Kioxia)SHUHEI OCHIAIJune 13, 2026 06:54 JSTTOKYO -- Japanese memory maker Kioxia Holdings is now the top Japanese company by market capitalization, capping off a dramatic period that included postponed listings and years of uncertainty before its stock price soared 56-fold.