SoftBank Becomes Japan’s Most Valuable Company as AI Boom Fuels Record Rally

SoftBank Group shares surged to a new all-time high on Monday as investor enthusiasm surrounding artificial intelligence continued to drive demand for technology-related stocks.

The Japanese conglomerate climbed more than 13% during trading, reaching a record high of 8,546 yen. The strong performance helped lift Japan’s Nikkei 225 index, which gained approximately 1% on the day.

Following the rally, SoftBank’s market capitalization rose to roughly 48 trillion yen, equivalent to about $305.8 billion, allowing the company to surpass Toyota Group and become Japan’s most valuable publicly traded company.

AI Optimism Continues to Drive Investor Interest

The latest surge in SoftBank shares was largely fueled by growing confidence in the company’s exposure to the rapidly expanding artificial intelligence industry.

Investors have increasingly focused on SoftBank’s substantial stake in Arm Holdings, the British semiconductor designer that plays a critical role in the global AI ecosystem.

As demand for AI infrastructure and advanced computing power continues to accelerate worldwide, Arm has emerged as one of the key beneficiaries of the industry’s growth.

Arm Holdings Positioned to Benefit From Nvidia’s New Chips

Investor optimism received an additional boost after Nvidia unveiled a new generation of processors that will utilize Arm’s technology platform.

Nvidia’s latest Arm-based processors are expected to power a range of upcoming Windows devices developed in partnership with Microsoft.

The development is particularly significant for Arm because the company generates a large portion of its revenue through licensing agreements that allow manufacturers to use its chip architecture.

As adoption of Arm-based AI processors expands, the company stands to benefit from higher licensing revenue and broader industry demand.

Arm Remains the Crown Jewel of SoftBank’s Portfolio

Many analysts consider Arm Holdings to be the most valuable asset within SoftBank’s investment portfolio due to its direct exposure to artificial intelligence and semiconductor markets.

SoftBank currently retains approximately 90% ownership of Arm, giving investors significant exposure to the chip designer’s future growth potential.

Shares of Arm have more than tripled in value during 2026, extending gains generated during the broader AI-driven rally that has dominated technology markets over the past two years.

The stronger Arm performs, the more valuable SoftBank’s investment becomes.

OpenAI Investment Adds to Momentum

In addition to Arm’s success, SoftBank has also benefited from its investment in artificial intelligence startup OpenAI.

The company recently disclosed substantial gains from its OpenAI position, further strengthening investor confidence in SoftBank’s AI-focused strategy.

The combination of Arm’s growth and OpenAI’s rising valuation has helped drive a significant re-rating of SoftBank shares throughout the year.

SoftBank Stock Up More Than 80% in 2026

SoftBank has been one of the strongest-performing major stocks in Japan this year.

Following Monday’s rally, the company’s shares have gained more than 80% since the start of 2026, reflecting investor enthusiasm for businesses positioned to benefit from the global AI revolution.

The stock’s performance has significantly outpaced many traditional industrial and automotive companies, including Toyota.

€75 Billion AI Investment Planned for France

Over the weekend, SoftBank further reinforced its commitment to artificial intelligence by announcing plans to invest approximately €75 billion, or $87.3 billion, in AI infrastructure projects across France over the next five years.

The investment is expected to support the development of data centers, computing infrastructure, and other AI-related technologies, underscoring SoftBank’s long-term commitment to the sector.

With major stakes in Arm, OpenAI, and global AI infrastructure projects, SoftBank continues to position itself at the center of one of the fastest-growing technology trends in the world.