SoftBank surges 13% on Arm and OpenAI gains

SoftBank Group’s stock rose about 13% in Tokyo on Monday after gains linked to its stakes in Arm and OpenAI and a record annual profit prompted investors to revalue the company.

SoftBank owns nearly 90% of Arm Holdings. Arm develops chip architectures used in smartphones, servers and increasingly in AI computing systems. Because of SoftBank’s large holding, rises in Arm’s share price increase SoftBank’s net asset value.

SoftBank has committed cumulative investments in OpenAI expected to reach $64.6 billion once planned follow-on tranches are completed. The group has recorded roughly $45 billion in gains related to its OpenAI holdings. OpenAI filed confidential paperwork for a U.S. initial public offering on June 8, which drew additional investor attention to those stakes.

UBP senior equity adviser Vey Sern Ling described SoftBank’s share price as reflecting the moves of its stake holdings, including Arm. Rolf Bulk of Futurum Group described the company as providing early exposure to the OpenAI IPO and access to the fastest-growing segment in AI semiconductors.

For the year ended March 2026, SoftBank reported a record annual profit of about 5 trillion yen and revenue of roughly 7.8 trillion yen. The Vision Fund recorded a major OpenAI-linked gain in the March quarter. After the results, SMBC Nikko raised its price target for SoftBank to 8,500 yen from 5,200 yen.

SoftBank has also made direct investments in AI infrastructure. The group committed tens of billions of euros to projects in France and is a central backer of Stargate, a roughly $500 billion U.S. AI infrastructure project involving OpenAI and Oracle. Masayoshi Son has argued that the AI expansion could exceed the scale of the dot-com boom and that physical AI and robotics may become a large new market.

The stock’s rally briefly pushed SoftBank past Toyota on June 1 to become Japan’s most valuable listed company. Market participants and analysts have linked recent share moves to the performance of SoftBank’s major holdings rather than changes in the group’s core operations.