Twitter's billionaire Co-founder Jack Dorsey, who Co-founded fintech startup Block (previously Square), has changed his title of CEO at Block to 'Block Head and Chairperson'. "There will be no changes in Dorsey's roles and responsibilities," Block said in a regulatory filing. World's richest person Elon Musk tweeted to Dorsey, "Your new title at Block is...," followed by two fire emojis.