This insurer was Buffett's secret stock earlier this year, and it's easy to see why he was so interested.One of Berkshire Hathaway's (BRK.A 0.23%) (BRK.B -0.02%) newest stock investments is insurance giant Chubb (CB -0.55%). In this video, Fool.com contributors Matt Frankel and Tyler Crowe discuss why Buffett might be so interested in this massive insurance company.*Stock prices used were the morning prices of Sept. 12, 2024. The video was published on Sept. 13, 2024. ...