After a year in which a string of formerly obscure and esoteric acronyms have repeatedly triggered financial shocks, another set of letters is sowing the seeds of fear in investors’ minds.

Power-reverse dual currency bonds are the latest instruments to cause concern. PRDCs, which have been principally issued in Japan, are long-dated bonds, usually with a maturity of about 30 years, with coupons linked to movements in a foreign currency such as the US or Australian dollar.