Why More Demand for Japanese Stocks Is Bad News for the Yen

The yen has been the worst-performing major currency in the past month as optimism over U.S.-China trade talks and Brexit sapped demand for havens. Another reason it is declining is more curious: increased trading of Japanese stocks by overseas investors.

The dynamics work like this: foreign funds have boosted trading of Japanese shares but they are unwilling to take on currency risk at the same time. For that reason they choose to hedge purchases for foreign-exchange movements, which typically involve selling yen via forward contracts that roll over periodically. As stock prices rise, they have to increase hedging, putting additional pressures on the currency.