Softbank’s Masayoshi Son becomes Japan’s richest with $71 billion fortune as AI bet pays off
Sign up now: Get ST's newsletters delivered to your inbox
Softbank founder Masayoshi Son (left) has become one of US President Donald Trump's key foreign backers.
PHOTO: AFP
Follow topic:
TOKYO - Mr Masayoshi Son’s big wager on artificial intelligence has paid off – propelling the SoftBank Group founder past Uniqlo billionaire Tadashi Yanai to become Japan’s richest person.
Mr Son’s net worth soared 248 per cent in 2025 to US$55.1 billion (S$71 billion) on Oct 29, about US$23 million larger than Mr Yanai’s, the chairman and biggest shareholder of Uniqlo’s parent company Fast Retailing.
Mr Yanai has been at the top of the country’s ranking for most of the past decade, and continuously since April 2022, according to the Bloomberg Billionaires Index.
The recent spike in Mr Son’s fortune mirrors the performance of Tokyo-listed SoftBank, where the Japanese billionaire is the biggest shareholder with a stake of about one third.
Mr Son, 68, controls a global portfolio of tech investments from chipmakers to start-up ventures, and has embarked on a spending spree in 2025 to try and position the firm as a linchpin in the global AI boom.
SoftBank shares climbed on Oct 29 after it was listed among companies interested in launching projects in the United States during President Donald Trump’s visit to Tokyo.
Mr Son has become one of Mr Trump’s key foreign backers in global business, making an early pledge this year for US$100 billion in US investments.
His most ambitious deals now include a planned US$30 billion investment in OpenAI and a US$500 billion initiative to build AI data centres and other infrastructure across the US in partnership with the ChatGPT operator, Oracle and Abu Dhabi fund MGX.
Mr Son is also seeking to team up with Taiwan Semiconductor Manufacturing Co for a trillion-dollar industrial complex in Arizona for AI and robots.
The gains linked to OpenAI, Arm Holdings and other AI bets have helped buoy SoftBank, with its shares becoming a proxy for the AI infrastructure spending boom.
Mr Son’s new darlings include a surprise US$2 billion investment in Intel, the acquisition of ABB’s robotics arm for US$5.4 billion and fresh exposure to Nvidia and TSMC.
Mr Son, an ethnic Korean born in Japan in 1957, began his entrepreneurial career while studying in the US by developing an electronic dictionary that he famously sold to Sharp Corp for around US$1 million.
After returning to Japan, he founded SoftBank in 1981 as a distributor of computer software.
Over the past four decades, the business has evolved into a conglomerate spanning telecommunications, digital payment and technology investment.
To be sure, some investors caution that AI valuations have run too high, warning that OpenAI and Nvidia are fuelling a complex web of business transactions that is artificially propping up the trillion-dollar AI boom. BLOOMBERG
