Buffett remains active at 96, but Berkshire's shares aren't doing much

As Warren Buffett turns 96 in his first birthday since stepping down as Berkshire Hathaway's CEO, the piece revisits the investing principles behind his six-decade run — patience, discipline, staying within his "circle of competence," and concentrating capital when conviction is…

Warren Buffett will be celebrating his 96th birthday on Sunday, but Berkshire Hathaway investors aren't celebrating the stock's anemic performance.