FRC Research · Launched June 2026

The Mortgage
Genome Project

Every lender has a decision DNA. We decoded it — 100+ behavioral features, 2.9M HMDA records, mapped as genes. Same borrower, different outcome. Now you know why.

100+

Decision genes per lender

2.9M

HMDA records analyzed

8 yrs

Behavioral history

∞

Same loan, different DNA

What is a decision gene?

A decision gene is a measurable behavioral trait extracted from a lender's historical approval and denial patterns. Just like a human gene codes for a specific trait — eye color, height — a lender's decision gene codes for a specific underwriting behavior.

We extract these genes from CFPB HMDA data: cliff points, variance slopes, stability scores, credit sensitivity, CLTV thresholds, income tolerance. Each one is a gene. Together they form a lender's decision DNA.

Example output

"Rocket Mortgage carries the CLTV-85 gene.
Above 85% LTV, Rocket's denial rate jumps +54.9 percentage points (2025 HMDA, 310K records).
MrCooper does not carry this gene.
Same borrower. Same loan amount. Different lender — different outcome."

The gene map — what we track

GENE · CLIFF-85

CLTV Cliff

A hard behavioral threshold at 85% loan-to-value. Rocket's denial rate jumps +54.9pp above this threshold (2025). CrossCountry: +47.5pp. MrCooper: +1.7pp — effectively absent. Source: 310,592 HMDA FHA records, 2023–2025.

↑ +54.9pp denial jump at 85% LTV (Rocket 2025) · MrCooper: +1.7pp

GENE · VAR-HI

High Variance

Decision inconsistency across similar borrower profiles. A high-variance lender may approve 580-score borrowers in Q1 and deny them in Q3 with no guideline change.

↑ Unpredictable approval odds

GENE · STAB-LO

Low Stability

Behavioral drift over 12-month windows. Lenders with this gene change their overlay thresholds frequently — what worked 6 months ago may not work today.

↑ High routing risk in volatile markets

GENE · DTI-SENS

DTI Sensitivity

Amplified denial response to debt-to-income ratios above 43% — beyond what FHA/Fannie minimum requirements specify. The lender applies its own overlay.

↑ 2.3× denial rate at DTI 43–50%

GENE · FICO-CLIFF

Credit Score Cliff

A hard floor above the agency minimum. Lender may nominally accept 580 FICO (FHA floor) but behavioral data shows near-zero approvals below 620.

↑ Hidden floor 40 points above stated minimum

GENE · GEO-BIAS

Geographic Concentration

Behavioral preference or aversion toward specific metro markets. Some lenders quietly pull back from high-denial-rate metros without announcing a policy change.

↑ 22% lower approval in flagged metros

DNA comparison — same file, two lenders

Below: a 600 FICO, 88% LTV, 46% DTI FHA purchase file run through two lender DNA profiles.

Lender Decision DNA — Visual Map

Rocket Mortgage

C85

FCO

VAR

STB

DTI

GEO

OVL

—

MrCooper

C85

FCO

VAR

STB

DTI

GEO

OVL

—

Active risk gene

Present, low risk

Gene absent

Gene	Rocket Mortgage	MrCooper	Impact on this file
CLIFF-85	ACTIVE	absent	88% LTV triggers denial cliff at Rocket
FICO-CLIFF	ACTIVE	mild	600 FICO below Rocket's hidden floor (~620)
DTI-SENS	ACTIVE	absent	46% DTI amplified at Rocket, neutral at MrCooper
VAR-HI	present	absent	Rocket's decision less predictable quarter-to-quarter
STAB-LO	absent	present	MrCooper overlays shift more frequently

Verdict on this file: Rocket → likely denial. MrCooper → viable path. Same loan. Same borrower. Different DNA. Source: CFPB HMDA 2025, 310,592 FHA records, CLTV cliff verification June 2026.

Why nobody did this before

HMDA data has been public since 1975. But nobody treated lender behavior as a genetic system — extracting features, classifying traits, building comparable profiles. The academic literature focuses on fair lending disparities. The industry focuses on rate sheets. Nobody mapped the behavioral DNA of the decision itself.

We did. 2.9 million records. 8 years. 100+ features per lender. This is the first structured behavioral genome for the US mortgage market.

Run your file through the DNA matcher

Zai matches your borrower profile against lender decision DNA — routing to lenders whose genes won't trigger a denial.

Route with Zai →

Fair Lending Note: FRC analyses exclude all protected-class variables present in HMDA (race, ethnicity, sex, age). We model lender behavior across financial variables only — DTI, CLTV, loan type, property type, and outcome. We measure how institutions decide, not who applies.

The Report · PDF

The Mortgage Black Hole Report 2025

Every major FHA lender's 97%+ denial zone, mapped cell by cell — plus how the same zone is treated by five other lenders. 11 pages, 310,592 records, full methodology.

Get the report — $49 → Instant download · Secure checkout by Lemon Squeezy

Source: CFPB HMDA Public Loan-Level Dataset 2018–2025 · Analysis by FinanceRateCalc Decision Intelligence · Gene classifications are behavioral models derived from historical data, not official lender policy. All-cash purchases (~39% of 2025 U.S. home sales, ATTOM) are not captured in HMDA and are excluded from this analysis. For informational purposes only — not financial advice.

← All Tools · Lender Stress Index · Denial Clock