There were growing concerns that the Syriza party, which opposes bail-outs and any form of adherence to related fiscal discipline, could soon come to power in Greece. The markets were also unnerved by a warning from the International Monetary Fund that less than a third of the eurozone’s banks have balance sheets strong enough to rebuild their reserves and boost lending; a sign that the “stress tests” scheduled for later this month could hold some nasty surprises.