SoftBank's Stock Hits a New High, Up Nearly 40% in Under a Week

News of OpenAI's upcoming IPO has led to SoftBank's cumulative rise of 40% in five days, with a market capitalization surpassing 40 trillion yen (about $252 billion), and once again setting a historical high during trading on Monday.

SoftBank rose by 4.6% in the Tokyo stock market on Monday, continuing the sharp upward trend from last week's two days. The direct catalyst for this round of market movement is the market rumor that OpenAI is preparing to submit an IPO application in the near future, while SoftBank's power infrastructure subsidiary, SB Energy, also announced plans to secretly submit listing documents in the United States. SoftBank is one of the largest shareholders of OpenAI and has committed about $65 billion in investments, with an expected stake ratio of about 13% by October this year.

Behind this rebound, there is a structural shift in market sentiment—the rising expectations for OpenAI's listing, which to some extent alleviates previous market concerns about competitors like Anthropic, Google, xAI, and others closing in.

IPO expectations re-evaluate the value of AI assets

Bloomberg cited Senior Analyst Nakagawa Ryū from the Tokai Tokyo Smart Research Institute, who stated that the market is "extremely excited" about OpenAI's long-awaited IPO, and that the listing will help improve the current opaque status of AI field valuations. However, he also warned that "the current rise in stock prices is purely based on expectations, and the key is to see where OpenAI's market value can stabilize after the listing."

SoftBank's investment portfolio is highly concentrated in unlisted AI-driven tech companies, including ByteDance, Coupang, etc. If OpenAI can successfully go public, it will provide a rare public market pricing anchor for SoftBank's holdings and is of significant reference for the overall asset valuation. Meanwhile, last week's better-than-expected NVIDIA financial report and rising Arm stock prices also provided additional support for SoftBank's rebound.

SB Energy: The infrastructure pillar of Son Masayoshi's data center ambitions

SoftBank's SB Energy focuses on power generation and grid management and is a core infrastructure carrier of founder Masayoshi Son's plan to massively deploy data centers in the United States. Over the past year, the company has raised more than $1.8 billion from SoftBank, OpenAI, and Ares Management.

If SB Energy's listing in the United States can become a reality, it will make SoftBank's layout in the AI infrastructure field clearer and provide a more direct market test for its positioning on the AI value chain.