Japanese billionaire Masayoshi Son loses $3.9 billion as SoftBank shares plunge 11% in Asian chip rout

Japanese billionaire Masayoshi Son lost about $3.9 billion on Friday as SoftBank Group shares tumbled roughly 11%, the biggest loss among Asia’s tech tycoons as Wall Street’s AI selloff spread across the region.

The decline cut Son’s fortune to about $29 billion, according to Bloomberg wealth data cited by Odaily. Son is SoftBank’s founder and largest shareholder, so the stock’s moves drive most of the swings in his wealth.

Son led a broad retreat among the region’s richest people. Twenty-two billionaires from China, Japan and South Korea lost more than $21 billion at one point on Friday, before trimming those losses to about $18 billion, according to the same data.

Meanwhile, others also took heavy hits. Samsung Electronics Chairman Lee Jae-yong, together with his mother and sister, saw the family’s wealth fall by about $2.5 billion. Keyence founder Takemitsu Takizaki and ASE Technology’s Zhang Qiansheng each lost at least $1 billion.

The selloff began in New York. On Thursday, the Nasdaq Composite fell 5.5% and the PHLX Semiconductor Index plunged more than 12%, as investors fled AI-linked stocks after Democrats won control of Congress and pledged tighter restrictions on data centers.

Asian markets followed on Friday. South Korea’s Kospi fell more than 8%, triggering a temporary trading halt, before resuming about 7% lower. Japan’s Nikkei dropped roughly 6%, on track for its worst day in eight months, and Taiwan’s benchmark index fell more than 8%.

Chip stocks led the declines. SK Hynix fell 11.7%, Samsung Electronics dropped nearly 10%, and Taiwan Semiconductor Manufacturing lost 8.5%, according to Fox Business.

SoftBank is especially exposed to the AI trade. Son has bet heavily on artificial intelligence, including large investments in OpenAI and chip designer Arm Holdings, and the company’s shares tend to move sharply with sentiment toward the sector.

That exposure has also raised questions about SoftBank’s debt. The cost of insuring the company’s bonds against default jumped to a four-year high this week as AI fears rattled markets, according to Reuters.

The losses mark a sharp reversal for Son, whose fortune surged earlier this year as investors piled into AI stocks. He briefly held the title of Asia’s richest person before SoftBank’s slide handed it back to Mukesh Ambani.

Still, there were signs of stabilization. US stock futures rose on Friday after Thursday’s rout, while President Donald Trump blamed the Democratic election victories for the selloff and predicted that markets would rebound.