A mere four months after co-chief executive Anshu Jain declared the end of Deutsche Bank's "hunger march" following a €3 billion capital increase, the bank is again on the defensive, trying to persuade investors and regulators that it is sufficiently capitalised.

To its critics, the bank's claims-to be "one of the best capitalised banks in the world"-appear to have fallen on deaf ears as its earnings outlook has clouded. Deutsche Bank's shares have dropped 7.3% since late July, closing on Wednesday in Frankfurt at €33.50.