The fall from grace has been swift and hard. Buying high-yielding subordinated bank bonds that count toward tier one capital was a hot trade in a world where investors were scrambling for yield. This is a case where markets have been their own worst enemy.

European banks have been at the centre of the recent market storm, with Deutsche Bank's bonds particularly in focus. The move in prices has been big, even with a bounce in the last couple of days. Bank of America Merrill Lynch's index of contingent capital bond - popularly known as CoCos - has dropped 7.6% in 2016.