Some $4.60 billion in jumbo mortgage-backed securities were issued in the first quarter of 2015, the highest quarterly volume seen in the aftermath of the financial crisis, according to Inside Nonconforming Markets. Jumbo MBS activity has had large swings in recent years due to shifting investor appetite and volume hasn’t been anywhere near the levels seen before 2008. However, the market recovered from an unexpected increase in interest rates ... [Includes one data chart]