And while the DOJ makes much of the Herfindahl-Hirschman Index, a measure of industry concentration that would leap if the merger goes through, a court victory will depend mostly on whose experts are more convincing.
By way of example, the heavy issuance over the past several years of U.S. Government debt has increased the concentrationof government-related securities in the Barclays Aggregate index, the customary benchmark for taxable fixed income mandates.