Warren Buffett, the billionaire investor who turned an aging textile mill into a more than $1 trillion conglomerate, said he’s “going quiet,” marking the end of an era for one of the business world’s most-watched investing gurus.

In a letter disclosing that he’s donating more than $1.3 billion to four family foundations, the 95-year-old investor, who is stepping down from his role of chief executive officer at the end of the year, said he’s going to stop writing Berkshire Hathaway Inc.’s annual letters and speaking at its meetings.