Berkshire Hathaway Inc. has increased its investments in Japan's largest trading companies following Warren Buffett's announcement in a shareholder letter. Documents filed with Japan's Finance Ministry revealed that Berkshire raised its holdings in Mitsubishi Corp., Marubeni Corp., Mitsui & Co., Itochu Corp., and Sumitomo Corp.

Buffett expressed interest in boosting ownership in the trading houses in a recent annual letter to shareholders. He initially invested in these companies in 2020 and expanded his stake in June 2023. Although there was an agreement to limit ownership below 10%, the trading houses agreed to relax this restriction as mentioned in the investor letter.

Investors had been anticipating Buffett's next investment move after Berkshire Hathaway conducted a ¥281.8 billion ($1.9 billion) multi-tranche bond sale in October 2024. Buffett's focus on Japanese stocks could help boost market sentiment amid concerns about rising interest rates, currency strength, and global trade tensions.

Details from filings to Japan’s Finance Ministry indicate the stake increases in the following companies:

- Mitsui & Co.: from 8.09% to 9.82% - Mitsubishi Corp.: from 8.31% to 9.67% - Sumitomo Corp.: from 8.23% to 9.29% - Itochu Corp.: from 7.47% to 8.53% - Marubeni Corp.: from 8.30% to 9.30%