Jack Ma quietly invested $30 million in Corgi, one of Y Combinator's hottest startups Alibaba cofounder Jack Ma. Wang HE/Getty Images Jack is back.Chinese billionaire Jack Ma's private equity firm secretly led the latest funding round for Corgi, marking the first time the firm is known to have invested in a startup founded in the US.Yunfeng Capital, co-founded by Jack Ma and businessman David Yu, funded Corgi with about $30 million, according to a source familiar with the matter and corresponden...