Credit concerns have increased this year as defaults, while still low by historical standards, continue to move higher. The U.S. leveraged loan default rate ended the first quarter at 2.8%, up from 2% in the previous quarter, and up from 1% a year ago, according to Moody’s. In the first quarter, $7.3 billion of leveraged loans defaulted. Since then Vertellus, Peabody Energy  and Stallion Oilfield have defaulted this month