By Hannah Lang (Reuters) -Apollo Global Management, Oppenheimer, Jane Street and HSG, formerly known as Sequoia Capital China, invested in crypto exchange Kraken's recent funding round that valued the company at $15 billion, said two sources familiar with the matter. Fortune reported last month that Kraken closed the$500 million round, but Reuters is naming the firms, which are major investors and financial players, for the first time. Their participation underscores how institutional players are movin ...