Mortgage Stress Test
The mortgage stress test qualifies a borrower at the higher of the contract rate plus a buffer or the regulatory minimum qualifying rate.
Why it matters
mortgage stress test changes what a disciplined buyer can pay, how much debt the asset can safely carry, and whether the return is coming from operations or fragile assumptions.
Formula
Qualifying payment uses max(contract rate + required buffer, minimum qualifying rate).Worked example
In underwriting, tag mortgage stress test beside the exact source input and rerun the model when that input changes. The point is not a pretty metric; it is a better buy, hold, refinance, or walk decision.
How investors read it
Use it to kill bad deals quickly. If the back-of-envelope version does not survive conservative assumptions, do not spend five hours making it look alive.
Common mistakes
- · Treating the metric as a verdict instead of a screen.
- · Using broker-package assumptions without checking the source documents.
- · Ignoring taxes, capex, vacancy, financing terms, and timing.
Lender, insurer, and regulator rules change. Confirm current underwriting criteria before relying on the numbers.