SoftBank shares surged over 16% as a rally driven by Japan’s tech stocks lifted the Nikkei 225 to record highs, following a strong performance in U.S. markets, particularly the Nasdaq Composite, which also achieved new records due to rising AI-linked stocks. This upturn was interpreted as the Nikkei accounting for activity during Japan’s Golden Week closure, with rising optimism surrounding demand for datacenter infrastructure necessary for AI inference workloads. The positive sentiment was further bolstered by easing geopolitical tensions between the U.S. and Iran, contributing to a favorable market environment alongside declining oil prices.

Arm: Arm Holdings designs power-efficient processor architectures used widely in mobile devices, servers, and AI infrastructure. SoftBank, its majority owner, is leveraging Arm shares for funding AI initiatives like those with OpenAI. Arm’s stock advanced 13% in the recent U.S. rally, boosting optimism for its role in AI inference and datacenter CPUs.
OpenAI: OpenAI develops advanced AI models and enterprise solutions, including partnerships for AI agents and infrastructure. It has a strategic alliance with SoftBank Group to deploy tools across its companies and develop ‘Cristal intelligence’ for enterprise use. SoftBank’s exposure to OpenAI contributed to its share surge as investor optimism grows around AI demand.
SoftBank: SoftBank Group is a Japanese multinational investment holding company focused on technology and telecommunications ventures. It owns a majority stake in Arm Holdings and has committed significant resources to AI partnerships, including investments in OpenAI. The company’s shares surged over 16% amid a Japan tech rally, amplified by its ties to Arm and OpenAI.
Rolf Bulk: Rolf Bulk heads semiconductor and infrastructure research at The Futurum Group. He linked the stock rally to sustained AI infrastructure demand, noting CPUs’ critical role in AI inference and agentic systems with read-across from AMD’s performance to Arm.
Billy Leung: Billy Leung is an investment strategist at Global X ETFs, specializing in market trends and Asia-Pacific equities. He attributed the Nikkei rally to catch-up pricing after U.S. tech gains, highlighting SoftBank as a proxy for OpenAI and Arm investments.

Market Rally: Japan’s Nikkei 225 hit record highs driven by a tech stock surge following U.S. Nasdaq gains in AI-linked names.
AI Infrastructure: Investor optimism centers on rising demand for datacenter CPUs to support AI inference and agentic workloads.
Geopolitical Sentiment: Easing U.S.-Iran tensions contributed to positive market mood alongside falling oil prices.