The gap between the volume of non-financial corporate issuance this year compared with the same stage in 2015 has sharply narrowed since the ECB announced that investment-grade bonds from the sector would be included in its QE program. At the end of May, the 167.53 billion euros ($186.5 billion) of corporate bonds issued this year was 14.4 percent below the same point in 2015, a significant narrowing from 82 percent at the end of January. The central bank is expected to begin buying corporate bonds this month.