Objects under stress, from sapphire crystals to tectonic plates, seem to fracture in a similar way. The trick is to spot the hairline cracks when they first appear. Are such markers starting to show in the earnings of European companies?

Warnings across a range of sectors suggest pressure is not confined to banking. Nokia, software designer SAP, brewer InBev, retailer H&M and drug developer Roche have all disappointed in recent weeks. Weak results and cautious guidance point to nervous customers, rising raw material bills and an expensive euro.