The retreat, when it starts, could see the Australian currency return to its 2007 levels quite quickly.

FORBES: Aussie Dollar Could Be The Next Big Short

They are right up to a point: investors carry less currency risk if some of a bond's return is denominated in domestic currency.

ECONOMIST: Japanese bonds

Almost all of their issues are of dual-currency bonds: in return for the privilege of redeeming their debt in, say, dollars, borrowers pay higher-than-usual yen interest rates.

ECONOMIST: Japanese bonds