Warren Buffett’s Berkshire Hathaway Inc. has expanded its investments in Japan, raising stakes in Mitsubishi Corp. and Mitsui & Co. The news from the trading houses sent shares across the sector higher on Aug. 28, 2025.Increased Holdings in Mitsubishi and MitsuiA Berkshire unit boosted its voting rights stake in Mitsubishi to 10.23%, up from 9.74% in March, according to a Mitsubishi statement. Mitsui separately confirmed that Buffett’s firm also lifted its holding, though it remained below 10%. As of March, ...