Mortgage rates are at record lows, but by a key historical measure, they should be even lower....

|By:, SA News Editor

Mortgage rates are at record lows, but by a key historical measure, they should be even lower. The current coupon yield on mortgage-backed securities has fallen faster than 30-year mortgage rates; the spread is now 0.96 percentage points, almost double its average. Some say increased concentration among large banks that dominate the mortgage market helps explain the wide spreads.