Can someone walk through securitization from start to finish — origination, SPV, tranching, and waterfall?

Securitization transforms illiquid assets (loans, mortgages, receivables) into tradable securities. Here's the full chain:

Step 1: Origination

Brightwater Savings Bank originates $500M in residential mortgages. These sit on their balance sheet, consuming capital and concentrating risk.

Step 2: SPV Creation

Brightwater sells the mortgage pool to a Special Purpose Vehicle (SPV) — a legally separate entity. This achieves:

• Bankruptcy remoteness: If Brightwater goes bankrupt, the mortgages in the SPV are protected from creditors
• Off-balance-sheet treatment: Brightwater frees up regulatory capital
• True sale: The transfer must be a genuine sale, not a secured borrowing

Step 3: Tranching

The SPV issues securities in tranches with different priorities:

Step 4: Cash Flow Waterfall

Monthly mortgage payments flow through in strict priority:

Why It Matters for FRM:

The equity tranche absorbs the first 8% of losses — so if 5% of the pool defaults with 60% LGD, total losses are $15M, wiped entirely from the $40M equity tranche. The senior tranche is untouched unless losses exceed $100M (20%).

Key Risks:

• Moral hazard: Originator may lower lending standards if they plan to securitize
• Model risk: Tranche ratings depend on correlation and default assumptions
• Prepayment risk: Early mortgage payoffs reduce yields for senior tranches
• Servicer risk: Poor servicing can increase defaults across the pool

The 2008 crisis showed that when correlation assumptions were wrong, AAA tranches suffered catastrophic losses. FRM exam questions often test your understanding of how correlation affects tranche risk.

Explore securitization case studies in our FRM Part I course.