SoftBank CEO Masayoshi Son and OpenAI CEO Sam Altman attend an event to pitch AI for businesses in Tokyo, Japan Feb. 3, 2025.

Kim Kyung-Hoon | Reuters

SoftBank booked a yearly gain of $46 billion at its Vision Fund driven mainly by the huge rise in value of its investment in OpenAI.

The Japanese giant has invested more than $30 billion in OpenAI, with its investment gains in the company totalling $45 billion in the year ended March.

In the three months to the end of March, the Vision Fund saw a gain of around $20 billion, which was nearly all driven by OpenAI as SoftBank suffered losses on other investments such as Coupang , DiDi Global and Klarna.

SoftBank is looking to position itself in the center of the artificial intelligence boom with investments across various AI and chip companies , and Sam Altman's OpenAI forming the centrepiece.

SoftBank has committed to invest more than $60 billion in OpenAI which would give it around 13% ownership of the company, the company said in February.…