Warren Buffett’s Berkshire Hathaway has become a major shareholder of Mitsui after raising its stake, the latest bet that Japan’s trading houses will remain attractive. Fellow trading houses Mitsubishi, Itochu, Marubeni and Sumitomo were also up in Tokyo on Monday. Buffett first revealed stakes in Japan’s top five trading houses, also known as sōgō shōsha, in 2020. While Monday’s news isn’t surprising after the Mitsubishi stake increase, "the fact that the ‘god of investing’ is buying more is a tailwind for Japan’s trading house stocks,” said Ryunosuke Shibata, an analyst at SBI Securities Co. The diversified nature of the trading houses means that they have been able to weather a period of volatile commodity prices better than overseas rivals, while also sharpening focus on shareholder returns.