As investors look for new ways to cash in on the housing recovery, jumbo mortgages are starting to look more attractive, CNBC reports.

While the number of jumbo loans originated in the first quarter of this year was up 15% from a year ago, the number of those loans securitized and sold by lenders was up 400%, according to Inside Mortgage Finance. Four billion worth of jumbo loans were sold to investors, more than the $3.5 billion in jumbos originated in all of 2012.