Billionaire investor Kenneth Griffin, who has donated more than half a billion dollars to Harvard University, has halted his giving to the school over how it handled antisemitism on campus and a broader leadership crisis involving its president. Griffin, who started trading in his Harvard dormitory before becoming the most profitable hedge fund manager ever, told an audience at the Managed Funds Association conference in Miami on Tuesday that he stopped donations, for now. “No … And I’ve made that clear to members of the corporate board,” Griffin said when asked whether he was still supporting his alma mater financially....