Banks with the capacity to hold jumbo mortgages in portfolio were major contributors to jumbo mortgage-backed securities issued in 2013, according to a new ranking and analysis by Inside Nonconforming Markets. Fixed-rate mortgages also dominated the population of loans bundled into jumbo MBS last year. First Republic Bank was the biggest originator of securitized jumbos in 2013, with a market share more than double the next closest lender. Some $2.16 billion in originations from [Includes two data charts]