Market watchers are saying that Warren Buffett may be looking to buy Japanese financial firms and shipping companies as Berkshire Hathaway’s return to the yen bond markets fuels speculation he’s raising money to build stakes in value stocks.

The billionaire’s company this week mandated banks to manage a yen bond sale in the global market, in a sign he may increase holdings in Japan. Most of his previous investment in Japanese equities was financed through yen bonds, Buffett said in his annual letter in February.

Eiji Kinouchi, chief technical analyst at Daiwa Securities, sees potential for insurers and shippers to be Buffett’s next picks. While trading companies rose on news of the bond sale, they did not beat the broader market by a wide margin, he wrote in a research note this week. Instead, shippers and insurance stocks have been some of the top gainers in the Topix since August and may fit Buffett’s value investment strategy, he said.