Whether or not partial or whole Grexit prompts contagion will depend on the forces in favour of a transfer union amongst the remaining members. Syriza has been talking up the risks of contagion, describing it as a near certainty, because this was its main bargaining chip in seeking easier terms from the creditors. Unfortunately for them, so far at least, all the data that has come out has pointed to there being no run on other sovereigns. This implies that markets think that the forces in favour of the risk mutualisation required for calling the markets' bluff (that would take place on the ECB balance sheet) are healthy.