Who Is Masayoshi Son? Biography, Net Worth, and the SoftBank Story

Masayoshi Son is one of the most consequential — and most volatile — figures in global technology investing. The founder, chairman, and CEO of Japan'sSoftBank Group, he turned a small software-distribution startup into a sprawling investment empire, made one of the greatest venture bets in history with an early stake in Alibaba, created the $100 billion Vision Fund, and, in 2026, is steering the largest concentrated wager on artificial intelligence the industry has ever seen. His story is a study in extremes: a near-total wipeout in the dot-com crash, a record loss on WeWork, and repeated comebacks that have made him, at several points, the richest person in Japan.

Masayoshi Son: Quick Facts

Introduction: Japan's Boldest Tech Investor

For more than four decades, Masayoshi Son has been the most aggressive risk-taker in Asian business. Where most investors diversify to protect capital, he concentrates enormous sums behind a single conviction about where technology is heading — an instinct that produced both the Alibaba windfall, one of the most profitable investments ever recorded, and the WeWork debacle, one of the most public. He is admired as a visionary and dismissed as a gambler, and both descriptions hold truth.

What distinguishes him is his stated time horizon. SoftBank publishes a "300-year vision," and Son frames his bets around the multi-decade arc of what he calls the information revolution rather than quarterly returns. In 2026 that conviction has narrowed to one theme: artificial intelligence. Through chip designer , a multibillion-dollar position in OpenAI, and the $500 billion data-center venture, he has staked his legacy — and much of his personal fortune — on AI becoming the defining platform of the century.

Early Life and Education

Masayoshi Son was born on August 11, 1957, in Tosu, a city in Saga Prefecture on the Japanese island of Kyushu. His family were Zainichi Koreans — ethnic Koreans living in Japan, in his case a third-generation immigrant family. Like many Zainichi at the time, they used a Japanese surname (Yasumoto) to navigate the discrimination Korean residents faced. Son grew up poor; his grandfather had come to Japan as a laborer, and his father ran small enterprises, including pachinko parlors and a pig-and-chicken operation.

Being part of a stigmatized minority shaped him. As an adult, Son made a deliberate choice to use his Korean family name rather than the Japanese name his family had adopted — an unusual public assertion of identity for a prominent Japanese businessman of his generation.

A turning point came in his teens. Inspired after meeting Den Fujita, the entrepreneur who brought McDonald's to Japan, Son resolved to study in the United States. He moved to California, raced through high school in weeks, attended Holy Names College, then transferred to theUniversity of California, Berkeley, graduating in 1980 with a degree in economics.

Berkeley was where his commercial career effectively began. As a student, Son developed an electronic pocket translator and licensed the design to Sharp Corporation, reportedly earning around $1 million — a remarkable sum for an undergraduate, and the seed capital for what followed. He also met his future wife, Masami Ohno, while both were students there.

Career: From Software Distributor to Investment Empire

Founding SoftBank (1981)

Son returned to Japan and, in 1981, founded SoftBank as a distributor of packaged software and a publisher of computer magazines. The name signaled the ambition: a "bank" of software. As Japan's personal-computer market formed, SoftBank positioned itself as the layer between software makers and retailers, and grew quickly into the country's dominant distributor.

From Software to Telecom and the Internet

Through the 1990s and 2000s, Son repeatedly reinvented the company. In 1996 he formed a joint venture with Yahoo to createYahoo Japan, which became the country's leading internet portal and one of SoftBank's most durable assets. He then pushed into broadband with Yahoo BB, undercutting incumbent NTT on price to force Japan online.

He then moved into mobile telecom. In 2006, SoftBank bought Vodafone's Japanese operations, rebranded them as SoftBank Mobile, and used an exclusive early iPhone deal to climb the carrier rankings. In 2013 it took control of the struggling U.S. carrierSprint— a costly, years-long turnaround eventually folded into a merger with T-Mobile.

The Legendary Alibaba Bet

In 2000, Son made the investment that would define his reputation. After a brief meeting with a then-little-known English teacher named Jack Ma, Son put roughly $20 million into Ma's fledgling Chinese e-commerce company, Alibaba. By the time of Alibaba's 2014 IPO — at the time the largest in history — SoftBank's stake was worth on the order of $75 billion, one of the highest-multiple venture returns ever achieved.

The stake anchored SoftBank's balance sheet for two decades. Between roughly 2021 and 2024, Son progressively sold it down — partly through prepaid forward contracts — booking enormous gains (one 2024 filing pointed to a gain of around 1.26 trillion yen, on the order of 425 times the original outlay) and ending SoftBank's run as Alibaba's largest shareholder. The proceeds helped fund his next act. See .

The Arm Acquisition (2016)

In 2016, SoftBank paid about $32 billion to acquireArm Holdings, the British company whose chip architecture powers the vast majority of the world's smartphones and a growing share of other devices. Critics questioned the price and the strategic logic at the time. A decade later, with Arm's designs increasingly central to AI and data-center silicon, the deal looks prescient — Arm has become arguably the single most important asset in Son's portfolio.

The Vision Fund Era

In 2017, Son launched theSoftBank Vision Fund, a roughly $100 billion vehicle — by far the largest technology fund ever assembled. Anchored by a huge commitment from Saudi Arabia's Public Investment Fund and Abu Dhabi's Mubadala, alongside Apple and others, it could write checks that dwarfed traditional venture firms. Son took large positions in Uber, DoorDash, ByteDance, Coupang, and dozens more, often pushing founders to "go bigger" and lifting valuations across the startup world. A second Vision Fund followed. See .

Net Worth and Sources of Wealth

As of May 2026, Masayoshi Son's net worth is estimated at roughly$60–70 billion, with Forbes placing it near $69 billion — enough to rank him the richest person in Japan and among the 30 wealthiest worldwide. Different trackers produce meaningfully different numbers because so much of his wealth tracks one fast-moving variable: the share price of SoftBank Group.

The components of his fortune are relatively concentrated:

• SoftBank Group stake.Son owns roughly a third of SoftBank Group, the overwhelming majority of his wealth.
• Arm Holdings.SoftBank owns about 90% of Arm, so Arm's market value — which swings sharply with AI sentiment — feeds directly into Son's net worth.
• SoftBank Corp.The domestic Japanese carrier provides steadier cash flow.
• Vision Fund holdings.A diversified but volatile book of technology stakes, public and private.

This concentration explains his extreme volatility. His fortune reportedly surged in 2025 — by some measures more than doubling — as AI optimism lifted SoftBank and Arm. At the dot-com peak in early 2000, his paper wealth is widely reported to have approached $78 billion, by some accounts briefly making him the world's richest person, before the crash erased most of it. Few billionaires have seen their net worth swing by tens of billions as often as Son has.

Leadership Style and Philosophy

Son's investing philosophy rests on a few consistent ideas. The first is the very long horizon: SoftBank's published "300-year vision" frames the company as meant to outlast any single product cycle, and Son routinely justifies near-term losses as the price of positioning for a multi-decade shift. The second is a near-religious belief in technological acceleration — that an "information revolution," and eventually a form of artificial superintelligence, will reshape human life. The third is decisiveness bordering on impulsiveness: he reportedly decided to back Jack Ma after a meeting measured in minutes, on conviction rather than a spreadsheet.

He tends to concentrate rather than diversify, to favor founders with outsized ambition, and to use leverage aggressively. Supporters call this visionary conviction; critics call it gambling with borrowed money. Governance experts have repeatedly flagged how tightly SoftBank's strategy is bound to one person's instincts, and the company has at times struggled with succession, including the 2021 departure of his presumed successor, Marcelo Claure.

Notable Topics and Controversies

The Dot-Com Near-Wipeout

When the dot-com bubble burst in 2000–2001, SoftBank's share price collapsed by roughly 99% from its peak, and Son lost the overwhelming majority of his paper fortune within months — one of the largest personal wealth destructions in history. That he rebuilt the company through the broadband and mobile eras, rather than fading away, is central to his reputation for resilience.

The WeWork Disaster

The Vision Fund's investment in WeWork became the cautionary tale of the era. SoftBank poured billions into the office-leasing company at valuations that reached roughly $47 billion. When WeWork's 2019 IPO attempt collapsed amid scrutiny of its finances and governance, SoftBank was forced into a costly rescue and a dramatic write-down. WeWork filed for bankruptcy in late 2023. The episode damaged confidence in the Vision Fund's discipline and in Son's judgment about founders.

The Vision Fund's Swings

The Vision Fund's results have whipsawed with the technology market. In the fiscal year ending March 2023, SoftBank disclosed a record loss of around $32 billion at the unit as valuations fell. Son responded defensively — selling assets, paying down debt, stepping back from earnings calls — before pivoting hard back into AI. The pattern of dramatic swings, rather than steady compounding, defines the fund's record and his broader, leverage-heavy approach to financing new bets.

Philanthropy and Personal Life

Son married Masami Ohno in 1979, and the couple have two daughters. He is generally private about his family, though he is known for an intense, work-centered life and a fascination with technology and history.

His most visible philanthropy came after the 2011 Tōhoku earthquake and tsunami, when he personally pledged around 10 billion yen and said he would donate his remaining salary until retirement to affected families, including those hit by the Fukushima nuclear accident. The disaster also pushed him toward renewable-energy advocacy. In 2016 he established the Masason Foundation, which funds scholarships for exceptionally talented young people in Japan — reflecting his belief that nurturing rare talent is among the highest-leverage investments a society can make.

Current Status in 2026: The All-In AI Bet

By 2026, Masayoshi Son has reorganized SoftBank around a single conviction: that artificial intelligence is the platform shift he has waited his whole career to catch at scale. Several moves define this phase:

• Arm at the center.SoftBank's roughly 90% stake in Arm — which completed a landmark Nasdaq IPO in September 2023, the largest tech listing of that year — is now the strategic core, as Arm's architecture moves into AI data-center chips, not just phones. See .
• The Stargate venture.Son chairs Stargate, a joint venture with OpenAI, Oracle, and investment firm MGX to build U.S. AI data-center infrastructure, with a headline commitment of up to $500 billion through the end of the decade. See .
• A major OpenAI position.SoftBank has committed tens of billions of dollars to OpenAI, making it one of the lab's most significant backers. See .
• Hardware and robotics.SoftBank has moved to acquire AI-adjacent hardware, including chip designer Ampere Computing and a robotics division from ABB, broadening the bet beyond software.
• Financing the war chest.To fund this scale, SoftBank has raised large bridge financing and tapped debt markets in 2026 — reprising the leverage-heavy approach that has long defined Son's playbook.

Whether this becomes the capstone of his career or its most expensive misjudgment will not be clear for years. Son frames it as the bet the previous decades were preparation for. For investors tracking the parent company, see .

Legacy

Son's legacy is already secure as the financier who, more than anyone, showed that a single investor could move the global technology market through the sheer scale of capital. He popularized the "mega-fund," changed how startups are funded, and made one of the defining bets of the internet age with Alibaba — while also exposing the model's downside in booms, busts, and spectacular write-downs. In 2026, his final chapter is being written in AI, and it remains genuinely open.

Frequently Asked Questions

Who is Masayoshi Son?

Masayoshi Son is a Japanese billionaire entrepreneur and investor — the founder, chairman, and CEO of SoftBank Group. He is best known for building SoftBank, an extraordinarily profitable early investment in Alibaba, the $100 billion Vision Fund, and his large 2020s bets on artificial intelligence through Arm, OpenAI, and the Stargate venture.

What is Masayoshi Son's net worth?

As of May 2026, his net worth is estimated at roughly $60–70 billion, with Forbes placing it near $69 billion — making him the richest person in Japan. The figure is highly volatile because most of his wealth is tied to the share prices of SoftBank Group and Arm Holdings.

How did Masayoshi Son make his money?

His wealth comes mainly from his roughly one-third stake in SoftBank Group, which owns about 90% of chip designer Arm, the SoftBank Corp. telecom business, and the Vision Fund's holdings. The original engine was an early Alibaba stake — about $20 million in 2000 — that grew into tens of billions.

Why is the Alibaba investment so famous?

Son invested about $20 million in Alibaba in 2000 after a short meeting with founder Jack Ma. By Alibaba's 2014 IPO the stake was worth on the order of $75 billion, making it one of the highest-return venture investments in history and the foundation of SoftBank's later ambitions.

What is the SoftBank Vision Fund?

Launched in 2017, the Vision Fund is a roughly $100 billion technology investment vehicle backed heavily by Saudi Arabia's Public Investment Fund. It made giant bets on companies like Uber, ByteDance, and WeWork, producing both large gains and large losses, including a record ~$32 billion loss in the fiscal year ending March 2023.

What is Masayoshi Son doing in 2026?

In 2026 Son has concentrated SoftBank around artificial intelligence. He chairs the Stargate AI-infrastructure venture (up to $500 billion with OpenAI, Oracle, and MGX), has committed tens of billions to OpenAI, holds Arm as the strategic core, and has acquired AI hardware and robotics capabilities.

This biography is compiled from public reporting and is general information, not financial advice. Net-worth figures are estimates that change frequently — verify against live sources before relying on them.