JPMorgan Chase this week issued the largest jumbo mortgage-backed security seen since the market started to return in 2010. The $940.06 million deal was backed by adjustable-rate mortgages originated by First Republic Bank. Previously, the largest post-crash deal was a $666.13 million jumbo MBS from Redwood Trust in February 2013. Prior to the financial crisis, many non-agency MBS had balances that topped $1.0 billion, while most jumbo MBS ...