Masayoshi Son, founder and largest shareholder of SoftBank Group, has seen his net worth rise by US$9 billion in the first half of August 2025, according to the Bloomberg Billionaires Index.

His wealth is now estimated at US$31.3 billion, making him the second richest person in Japan after Tadashi Yanai of Fast Retailing.

SoftBank, a Tokyo-listed investment group with holdings in global tech firms, has benefited from rising share prices linked to its AI investments.

The company’s Vision Fund has rebounded, and asset sales—including parts of its T-Mobile US stake—have increased Son’s available capital.

SoftBank shares have also surged following news of the company acquiring Foxconn’s EV plant in Ohio, a move that has spurred hopes for progress on its stalled Stargate data center project.

Son’s personal stakes in some of SoftBank’s investments have attracted scrutiny from investors concerned about governance.

🔗 Source: Bloomberg

🧠 Food for thought

1️⃣ Tech wealth volatility reflects the extreme boom-bust cycles of innovation investing

Son’s fortune demonstrates how concentrated tech bets can create massive wealth swings that mirror broader industry cycles.

His wealth dropped from briefly exceeding Bill Gates during the dot-com peak to losing $70 billion when tech stocks crashed, yet he persisted with his vision1.

The pattern repeated with his Alibaba investment—a $20 million stake that generated approximately 4,500% returns when the company went public, growing to a $132 billion valuation by 201812.

During the 2020 Chinese tech crackdown, his net worth plummeted to $8.4 billion, only to surge back to $38.3 billion just 12 months later as Vision Fund portfolio companies went public.

This volatility reflects the reality that concentrated positions in emerging technologies can deliver outsized returns during favorable cycles but create severe downturns when market sentiment shifts or regulatory environments change.

2️⃣ Aggressive scaling strategies produce both spectacular wins and costly failures

Son’s investment approach of pushing companies to take more capital than initially requested has created a track record of both massive successes and notable failures.