What containment actually buys, and what it does not

Where security is pooled across a loan book, a workout is never only about the loan in difficulty. It is about every other position that shares the same security, every other investor with a claim on it, and the order in which those claims are resolved. The negotiation widens before it narrows.

Holding each loan in a trust of its own removes that. The registered first mortgage securing a loan is held for that trust and for nothing else. A loan that runs into difficulty is worked out inside the trust that holds it, against the asset that secures it. Nothing crosses.

The honest limits

Containment is often oversold, so it is worth being exact about what it does not do.

It does not stop a loan defaulting. It does not improve recovery on the asset. It does not protect an investor from loss, because an investor is exposed to the performance of the book as a whole through the instruments they hold. A structure that isolates problems still passes the economic consequence of those problems to the people who funded them.

What it does is remove a category of contagion that has nothing to do with credit. It means a workout cannot be slowed by an unrelated borrower's position, and it means one impaired loan cannot encumber the security of nine performing ones. Those are process benefits, not credit benefits, and they are worth having for exactly what they are.

Why it is architecture rather than policy

The distinction that matters is where the protection sits. A manager can undertake not to cross-collateralise. An undertaking is only as good as its administration, and it can be varied.

If each loan sits in its own trust from the day it is written, there is no pooled security to cross-collateralise. The containment is a property of how the thing is built rather than a rule someone has agreed to follow, and it does not depend on anyone remembering to follow it.