Yesterday's re-jig of the European Central Bank's (ECB) collateral rules should push banks in the eurozone periphery away from using retained bonds, which can suffer from ‘wrong way risk', but also pose risks for countries whose sovereign ratings already sit at the single-A level.

According to Jan von Gerich, a global fixed income strategist with Nordea, the key move to watch for is if Canadian rating agency DBRS downgrades either Spain or Italy, which are both at the lowest possible rating in