According to market observers, as Berkshire Hathaway returns to the Japanese yen bonds market, there are speculations that Buffett is raising funds to buy value stocks, and may consider acquiring shares of Japanese financial and shipping companies.

The billionaire's company has this week commissioned a bank to manage a yen bond issuance in the global market, indicating that he may increase his investments in Japan. Buffett stated in his annual letter in February of this year that his previous investments in Japanese stocks were mostly financed through yen bonds.

Chief technical analyst Eiji Kinouchi from Daiwa Securities believes that insurance companies and shipping companies could be Buffett's next choices. In a research report this week, he wrote that although Japanese trading companies' stocks rose after the bond issuance news, they did not significantly outperform the market. He stated that on the contrary, since August, shipping and insurance stocks have been the top gainers in the TOPIX index, potentially in line with Buffett's value investment strategy.

"If it's not a trading company, this would have a significant impact on the entire market," Kinouchi said.

If Buffett increases his investment, it could inspire the Japanese stock market. Earlier this year, his support for Japan's five major trading companies drove the Nikkei 225 index to reach a record high.

The valuations of Japanese banks and insurance companies have declined after a massive stock market sell-off in August. Currently, the expected P/E ratios of the TOPIX insurance index and banking index are 9 times and 10.1 times respectively, compared to 12.1 times and 12.4 times in early July.

Senior strategist Takashi Ito from Nomura Securities also mentioned that Buffett is very likely to buy financial stocks. He said, "The fundamentals of the Japanese financial industry are strong, which aligns with Buffett's criteria."

Nomura analysts, including Tomochika Kitaoka, found that financial companies such as Mitsubishi UFJ Financial Group, Sumitomo Mitsui Trust Holdings, and Sompo Holdings all exhibit characteristics of Berkshire Hathaway's investment portfolio.

However, some observers of Buffett expect that, given Berkshire recently sold stocks of Bank of America, Buffett's investment focus may still be on Japanese trading companies.

Mineo Bito, the President and CEO of Bito Financial Services Company, often attends the Berkshire Hathaway shareholders' meeting held in Omaha, Nebraska, and he said, "I do not think he will buy Japanese bank stocks when selling U.S. banking stocks, he is very familiar with the U.S. market."