Vivek Ramaswamy, who unsuccessfully mounted a bid for the Republican presidential nomination, has purchased a 7.7% stake in BuzzFeed, a regulatory filing revealed Tuesday. The purchase raised questions about Ramaswamy’s intent. The filing indicated he intended to be an activist investor, pursuing discussions with management and BuzzFeed’s board of directors about strategy and even changes to ownership of the company. BuzzFeed is the parent company of HuffPost, which it acquired in 2021....