The Nikkei 225 index jumped over 2000 points to surpass 56,000 for the first time ever, significantly increasing the value of Berkshire Hathaway's investments in five major Japanese trading houses. Warren Buffett's stakes in these companies have nearly tripled since 2019, with Monday's rally generating nearly $2 billion in paper gains in a single day. Berkshire Hathaway's Japanese assets are now valued at over $41 billion, up from an initial investment of approximately $13.8 billion.