JPMorgan Chase is changing the servicing-fee structure in its latest prime non-agency mortgage-backed security. Many of the loans will be subject to a variable servicing fee as opposed to the flat fee traditionally used by Chase and many other issuers. Some 80.1 percent of the unpaid principal balance of the planned $513.9 million issuance is subject to the variable fee, a structure that is more commonly seen on MBS backed by nonperforming mortgages. The servicing fee will ...