Italian, Spanish and Greek sovereign bonds have emerged as the unlikely winners from this year’s bond market ructions, mounting a “relentless” rally that has narrowed the gap with Germany’s benchmark borrowing costs to nearly the smallest in more than a decade.

Bond fund managers said the turnaround from the Eurozone debt crisis, when the countries endured soaring borrowing costs, was due to stronger than expected growth and increased sharing of debt burdens by the bloc’s members.

Italy now pays only 0.9 percentage points more than Germany in 10-year borrowing costs, close to the lowest spread in a decade and a half. Spain is borrowing at a cheaper cost than France, the euro area’s second-biggest economy, with a spread of less than 0.6 percentage points.