The yen closed Friday with its biggest weekly gains in more than a month against the euro and the U.S. dollar. As you probably guessed, traders are moving funds into the yen as a safe haven to offset fears about the Ukraine-Russia crisis and China???s first bond default. And it???s very likely those fears will grow deeper over the weekend, as Russia continues to conduct ???military exercises??? on its Ukrainian border. For yen investors, that???s just what the doctor ordered, according to Manuel Oliveri of Credit Agricole in London. In fact, the yen may actually stand out as the one investment to play when there???s ???blood in the streets.??? But you???ll have to decide whether or not you can profit from others??? misfortune.