Normal service has been restored – or at least something approaching normality. After a three-day suspension in bank-to-bank trading of covered bonds, market-makers are back quoting prices but at a third of normal sizes and at three times the normal bid-offer spreads.

Monday’s revival brings to an end an uncomfortable hiatus. There is no reason why covered bonds should be going the way of commercial paper. They are as safe as safe gets, with barely a single default in their 238-year history. As they offer dual recourse – both to the pool of assets (usually mortgages and usually hugely over-collateralised) and the balance sheet of the bank itself – only a cataclysmic failure of the issuer, along with a collapse in the assets themselves, would trigger a default.