George Soros' successful bet against the British pound back in 1992 remains one of financial history's epic tales. In order to maintain the peg Britain raised interest rates and spent its foreign exchange reserves. But hedge funds, with Soros in the lead, sensed imminent failure and placed big bets against the pound. They were right: After some official bluster and shrill denials, Britain was in the end forced to withdraw from the ESM and devalue its currency, thus making fortunes for its hedge fund tormentors ($1 billion for Soros alone). Now fast forward to 2016. China has pegged its currency,...