On March 9, SoftBank's shares fell by 9.8%, more than double the overall decline of the Japanese stock market. This drop was triggered by OpenAI and Oracle's decision to abandon plans to expand their joint data center in Texas as part of the Stargate initiative, according to the Financial Times.

In just four months, shares of the Japanese giant have nearly halved in value. This trend reflects growing skepticism among investors regarding SoftBank's bet on the creators of ChatGPT.

SoftBank's stock price chart over the past six months. Source: Yahoo Finance.

In December 2025, SoftBank finalized a deal to invest $41 billion in the AI startup OpenAI, raising its total investment to $64.6 billion.

That same month, reports emerged that OpenAI had scaled back its spending plans by $800 billion following the failure of the Stargate initiative, which was projected to receive $500 billion in funding. The joint venture failed to form a team, appoint leadership, or begin construction of data centers. For months, partners struggled to agree on basic issues: who would build the facilities, who would own them, and how funding would be allocated.

From September to October 2025, top executives from the AI startup made multiple trips to Tokyo to negotiate with SoftBank's CEO Masayoshi Son. However, they could not resolve who would be the developer and owner of the flagship campus in Texas.

OpenAI considered pursuing the project independently, but lenders refused to provide funding.

Rating Downgrade

S&P has assigned a negative outlook to SoftBank's already low rating. This is due to the excessive amount of illiquid assets on the group's balance sheet, which account for more than half of its $320 billion investment portfolio.

S&P's decision complicates SoftBank's efforts to secure loans for further investments in OpenAI. To free up capital for the ChatGPT creator, SoftBank sold part of its Nvidia shares for $5.8 billion and a stake in T-Mobile for $9.1 billion in 2025.

The Financial Times noted that Son often becomes overly enthusiastic about a single sector and increases leverage until he faces pushback from shareholders or creditors.

Sometimes this approach pays off; for instance, SoftBank made an early bet on Alibaba. However, there are also failures, such as the collapse of WeWork.

Other companies closely linked to OpenAI are also feeling the pressure: shares of Oracle and CoreWeave have also shown declines.

SoftBank's interests extend beyond the ChatGPT developer. Recently, the corporation invested over $9 billion in robotics and digital infrastructure.

In February 2025, SoftBank and OpenAI agreed to establish a joint venture in Japan to provide AI services to corporate clients.