I believe that only the outstanding indebtedness can be securitized. If I owe Chase $5000, they may bundle that and sell the debt to a third party, getting a lump sum in return for remission of the money as I pay it off (with Chase also getting a fee for servicing the account).

However, I'm pretty sure that the future flows from the account are not securitized; i.e. the buyer doesn't participate in my future borrowing or repayments.

(I work on a team with a bunch of financial types, and one of them confirmed this, so it's less than notarized by Jamie Dimon, but more than idle speculation.)