Masayoshi Son

Roughly two years before the iPhone existed, Masayoshi Son flew to Steve Jobs carrying a hand-drawn sketch of an internet-capable phone and asked for the exclusive right to sell it in Japan. He got it, in writing, and then went out and bought a mobile carrier so he would have a network to run it on.¹

Son is the founder and chief executive of SoftBank, a Japanese conglomerate that started as a software distributor and became one of the largest technology investors in the world. He is not known for building a product himself, but for identifying which technology wave is coming next and buying, licensing, or financing his way into the infrastructure underneath it before the wave breaks.

Background

Son was born on August 11, 1957, in Tosu, Saga Prefecture, Japan, to a third-generation Zainichi Korean family. His grandfather had migrated from Korea and worked as a miner; the family used an adopted Japanese surname to assimilate, and his father built a fortune from bootleg sake, pig farming, and pachinko parlors. Son has said he experienced discrimination as an ethnic Korean in Japan and contemplated suicide as a teenager, describing Japan as a place where "if you are considered an outsider, it's not easy."¹

At 16 he read a biography of Den Fujita, founder of McDonald's Japan, and cold-called his way into a short meeting; Fujita told him to study computers and go to America.¹ Son moved to the US that year, finished high school in three weeks, and enrolled at UC Berkeley to study economics, where he built an electronic translator device he sold to Sharp for roughly 1.7 million dollars, adding close to another 1.5 million from a computer-game venture that became his seed capital at SoftBank's start. He graduated in 1980, sold a small company to Kyocera, then returned to Japan on a promise to his mother and began publicly using the surname Son.

Getting started

In September 1981, at 24, Son founded SoftBank in Fukuoka as a software distributor, working from a small office with two part-time employees who reportedly quit after his speech about a trillion-yen future for a company with no product or customers. He got a foothold at a consumer electronics show that year and grew monthly sales from about 10,000 dollars to over 2 million within a year.¹

In 1983 he was diagnosed with chronic Hepatitis B and told he might have three to five years to live; he ran the company from his hospital bed and survived, an episode he has said reshaped his risk tolerance afterward.¹ Through the 1990s SoftBank moved into publishing and telecom, acquiring US publisher Ziff Davis and investing in the fledgling Yahoo. In 2000, near the peak of the dot-com bubble, Son put 20 million dollars into a Chinese startup with no revenue, Alibaba, backing founder Jack Ma on what he later called "strong shining eyes" rather than a business plan.² When the bubble burst, SoftBank's share price collapsed roughly 99 percent within months, wiping out most of Son's paper net worth; the company survived, and the stake eventually became worth tens of billions.

What he built

SoftBank's defining move was in mobile. Wanting to enter Japan's carrier business in the mid-2000s, Son decided only Steve Jobs could build the "weapon" he needed. The network he bought to receive it was Vodafone's Japan operations, acquired in 2006, and SoftBank Mobile became Japan's exclusive iPhone carrier at launch in 2008. It later acquired US carrier Sprint and chip-design firm Arm Holdings for about 32 billion dollars; Arm's designs sit inside most of the world's mobile devices and, increasingly, AI chips, and returned to public markets in 2023 above a 50 billion dollar valuation.

In 2017 Son raised the SoftBank Vision Fund, at 100 billion dollars the largest tech investment fund ever assembled, including about 45 billion from Saudi Arabia's sovereign wealth fund, secured, Son says, in a single 45-minute meeting pitched as a "trillion-dollar gift" rather than a return forecast.² The fund backed Uber, WeWork, OYO, and dozens of others, alongside a second fund financed mainly by SoftBank itself. Results were uneven: WeWork's collapse cost SoftBank several billion dollars, and the first fund posted a loss around 18 billion in one fiscal year, while Alibaba and later AI holdings offset it. From the mid-2020s Son pivoted SoftBank toward AI infrastructure: Project Stargate with OpenAI and Oracle, a roughly 500 billion dollar US data-center plan, and a Japan "AI Grid" with Nvidia repurposing SoftBank's cell towers to carry AI compute.

How he operates

Asked on camera whether he was the finance guy rather than the creative one, Son accepted the framing: "If Steve is art and technology, I am finance and technology."¹ He describes his role as building the highway rather than the cars on it, a posture running through the iPhone deal, the Alibaba bet, and the Vision Fund alike, and one that anchors the Finance Plus Technology Builder archetype. He believes a founder's conviction matters more than the plan in front of him, saying he backed Jack Ma for his bearing rather than his business model, and is unusually direct about failure, summarizing the WeWork write-down in four words: "That is my mistake."³

Where things stand

As of the mid-2020s, Son remains SoftBank's founder and chief executive, without a named successor. SoftBank's fortunes are now closely tied to AI: its OpenAI stake, the Arm holding, and the Stargate commitment have driven sharp swings in Son's personal net worth, which has moved between roughly 30 billion and over 100 billion dollars within a single year as sentiment on AI spending has shifted. SoftBank sold its remaining Nvidia shares in late 2025 to help fund further OpenAI investment. Son frames these bets, including the Japan AI Grid, as the next iteration of the infrastructure-first strategy he has run since the iPhone deal.

Key facts

• Born August 11, 1957, in Tosu, Japan, to a third-generation Zainichi Korean family that used an adopted Japanese surname.
• By 19, had earned roughly 3 million dollars from the Sharp patent sale and a computer-game venture, his seed capital at SoftBank's start.
• Diagnosed with Hepatitis B in 1983, given three to five years to live; ran SoftBank from a hospital bed and survived.
• Secured exclusive Japan iPhone rights roughly two years before its 2007 announcement, then bought Vodafone Japan to build the carrier network.
• Invested 20 million dollars in Alibaba in 2000 with no revenue; the stake eventually became worth tens of billions.
• Raised the 100 billion dollar Vision Fund in 2017, including a 45 billion dollar Saudi commitment secured in one meeting.