Warren Buffett’s Berkshire Hathaway posted a 9% decline in 2020 operating income as the billionaire made “no sizable acquisitions” last year, while bumping up share repurchases. Berkshire’s (BRK.B) operating income in 2020 fell 9% to $21.92 billion year-on-year. Meanwhile, operating income in the fourth quarter of last year increased 14% to $5.02 billion. Furthermore, the investment conglomerate repurchased a stellar $24.7 billion of its own stock last year. “The math of repurchases grinds away slowly, but can be powerful over time,” Buffett wrote in his annual letter to Berkshire investors on Feb. 27. “The process offers a simple way for investors to own an ever-expanding portion of exceptional businesses.