Masayoshi Son net worth: how SoftBank’s AI bets drive his fortune up and down

Masayoshi Son’s net worth was about $29 billion (about ₹2.7 lakh crore) on 6 November 2026, according to the Bloomberg Billionaires Index, after SoftBank Group shares fell 10.8% in Tokyo and cut $3.9 billion from his fortune in a single day 1 2. Only five months earlier, Forbes valued him at $97 billion and named him Asia’s richest person 3.

The swing shows how closely the SoftBank founder’s wealth tracks the market’s mood about artificial intelligence. Most of it rests on his stake in SoftBank, whose biggest bets are on OpenAI and chip designer Arm. Rupee figures use ₹94.05 to the dollar, the rate on 7 November 2026.

Masayoshi Son net worth at a glance

Net worth (Bloomberg)	About $29 billion (about ₹2.7 lakh crore), 6 November 2026 1
Peak in 2026 (Forbes)	$97 billion (about ₹9.1 lakh crore), early June 2026 3
Main asset	About one-third of SoftBank Group 4
SoftBank’s key holdings	About 90% of Arm; a large stake in OpenAI 3
Role	Founder, chairman and chief executive, SoftBank Group
Source of wealth	Self-made

Why Masayoshi Son’s fortune fell so fast

SoftBank shares had fallen 38% in the month to 5 November and 28% over the past year, amid concerns about AI demand and OpenAI’s decision to push its stock market listing into 2027, the Financial Times reported 5. The US tech sell-off then spread to Asia: SoftBank closed 6.77% lower on 5 November and fell a further 10.8% on 6 November 6 2.

Debt worries added to the pressure. The cost of insuring SoftBank’s bonds against default rose to 466 basis points on 6 November, its highest level since October 2022 2. In the same week, China blocked SoftBank’s $5.4 billion purchase of ABB’s robotics division, a key part of Son’s plans for robots and “physical AI” 5.

What does Masayoshi Son own?

Son is SoftBank’s largest shareholder, with a stake of about one-third, so the company’s share price drives most of his wealth 4. Through SoftBank he controls a much larger set of assets than his personal fortune suggests.

• Arm Holdings: SoftBank owns almost 90% of the Nasdaq-listed chip designer, according to Morningstar analyst Dan Baker 3. Arm’s chip designs sit inside most of the world’s smartphones and a growing share of data centre processors.
• OpenAI: SoftBank had invested more than $30 billion (about ₹2.8 lakh crore) in the ChatGPT maker by mid-2026, according to Forbes 3. OpenAI is now valued at $1.25 trillion after its latest funding, as explained in OpenAI’s valuation.
• SB Energy: SoftBank plans to list its US data centre developer, which is targeting a $50 billion valuation, though OpenAI’s IPO delay has put pressure on that plan 5.
• Robotics: Son has been building a physical AI business, including the US company Roze, and is in talks to buy Allied Universal, the world’s largest private security group 5.

From Asia’s richest to a $29 billion fortune

In early June 2026, a rally of more than 80% in SoftBank shares made it Japan’s most valuable company, ahead of Toyota, with a market value of $298 billion. Forbes then valued Son at $97 billion, ahead of Mukesh Ambani as Asia’s richest person 3.

The two figures are not directly comparable. The $97 billion came from Forbes and the $29 billion from Bloomberg, and the two publishers value holding companies like SoftBank very differently. Even so, the direction is clear: Son’s paper wealth has fallen sharply since the summer. Our explainer on Forbes vs Bloomberg net worth sets out why such gaps appear.

Why SoftBank behaves like a leveraged AI bet

SoftBank funds many of its investments partly with borrowed money. That lifts returns when the value of holdings such as Arm and OpenAI rises, and deepens losses when it falls. It is one reason Son’s fortune moves more than the AI shares it tracks, a pattern covered in why tech sell-offs wipe billions off billionaires. When AI sentiment improves, the same structure can lift his wealth just as quickly.

What to watch next

Three things will shape Son’s net worth over the coming months: the timing and price of OpenAI’s listing, now expected in 2027; whether SoftBank can bring SB Energy to market; and whether it can rescue some form of the ABB robotics deal 5. Son’s full profile is on his Masayoshi Son page.

Sources

[1] Bloomberg, AI Elite Lose $18 Billion as Chip Stock Rout Spreads to Asia, 6 November 2026. [2] Billionaires.Africa, report citing Bloomberg on SoftBank shares and debt, 6 November 2026. [3] Ada Derana Biz (Forbes), SoftBank’s Masayoshi Son becomes Asia’s richest person amid AI boom, 3 June 2026. [4] Crain Currency (Bloomberg), Masayoshi Son becomes Japan’s richest. [5] Swissinfo (Financial Times), China blocks SoftBank’s $5.4bn takeover of ABB’s robotics division, 5 November 2026. [6] FourWeekMBA, SoftBank share moves on 5 November.

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