四年翻四倍，巴菲特押注日本股票超300亿美元

Core Insights - Warren Buffett is making significant investments in the Japanese market, particularly in five major trading companies, with the total value of Berkshire Hathaway's holdings surpassing $30 billion recently [2][3]. Group 1: Investment Growth - Berkshire Hathaway's holdings in the five Japanese trading companies have increased from approximately $6.3 billion at the time of initial disclosure in August 2020 to about $31 billion, representing a 392% increase [2][7][8]. - The stock prices of these companies have seen substantial growth, ranging from 227% to 551% during this period [9]. Group 2: Shareholding Changes - Berkshire Hathaway has increased its stake in Mitsui & Co. to 10.1%, with a market value of around $7.1 billion as of October 10 [4]. - Similarly, the stake in Mitsubishi Corporation has risen to 10.2% from 9.7% earlier this year [5]. - For Itochu, Marubeni, and Sumitomo, while there are no recent disclosures, it is widely expected that Berkshire's holdings may also be close to or exceed 10% [6]. Group 3: Investment Rationale - Buffett's initial attraction to these Japanese trading companies was due to their perceived undervaluation, especially considering the prevailing interest rates at the time [10]. - Initially, Buffett committed not to exceed a 10% stake without permission, but this limit was later adjusted to allow for increased holdings as the investment value became apparent [11][12].