Warren Buffett’s Berkshire Hathaway Inc. on Saturday said fourth-quarter profit swelled, boosted by gains in many of its businesses and common stock investments such as Apple Inc., and said annual earnings reached a record high. Berkshire also signaled renewed confidence in its own stock, repurchasing $6.9 billion in the quarter, and boosting total buybacks in 2021 to a record $27 billion. Buffett said Berkshire has repurchased another $1.2 billion of stock in 2022. In his annual letter to Berkshire shareholders, Buffett said buybacks make “good sense” when alternatives such as buying whole companies or more stocks appear “unattractive.” He also expressed confidence in Berkshire’s dozens of operating businesses such as the BNSF railroad and Geico auto insurer, after having gone six years since a major acquisition and letting Berkshire’s cash stake swell to $146.7 billion. “Today, internal opportunities deliver far better returns than acquisitions,” Buffett wrote. Quarterly operating income rose …