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IC Report on NQM Securitization

From prospectus upload to full IC package in minutes

SE

Shariff Elkordy

March 2026

I uploaded the prospectus for a Deephaven Residential Mortgage Trust deal (DRMT 20XX-X) and, within minutes, Graam's agent produced a full investment committee report.

The agent parsed the cashflow waterfall, extracted the capital structure, and converted the deal into an executable model directly from the document. It then ran the full underwriting workflow — collateral stratification, empirical benchmarking with NQM adjustments, loss and prepayment modeling, and cashflow projections across multiple scenarios.

Once the model was built, I could immediately interact with the deal: adjust pricing assumptions, run stress scenarios, inspect tranche-level cashflows, and evaluate breakeven loss across the capital structure.

Result: all senior tranches (A1–A3) are well-protected under both base and stress assumptions, while the B2 tranche emerges as the marginal credit risk position under elevated loss scenarios.

Here's the full IC-style report generated from that workflow.

Prepared for: Investment Committee

Asset Class: Non-Qualified Mortgage (NQM) RMBS

Deal Reference: @deephaven_nqm

1. Executive Summary

Deephaven Residential Mortgage Trust 20XX-X is a $480.9 million non-qualified mortgage (NQM) securitization. The pool comprises 1,116 residential mortgage loans with a weighted average coupon range of 4.375%–10.375%, a mix of 43.9% fixed-rate and 56.1% ARM collateral, and a notably high self-employed borrower concentration (60.5%). The deal is structured as a sequential-pay transaction with 7 offered tranches (A1 through B3) plus ancillary classes.

Key Pool Metrics

MetricValue
Issuance Balance$480,856,235
Loan Count1,116
WAC Range4.375%–10.375%
Fixed/ARM Split43.9% / 56.1%
Self-Employed Borrowers60.5% (primary NQM risk driver)
Investment Property Exposure19.9%

Under the base scenario (CDR 1.00% agency proxy, NQM-adjusted), all offered tranches (A1–B3) fully amortize with no principal shortfall. Senior tranches (A1–A3) exhibit short WALs of ~4.2 years at par, while mezzanine and subordinate tranches extend to 13–21 years. The AIOS and XS reference/excess classes show structural shortfalls consistent with their design as excess spread vehicles.

2. Deal Structure

2a. Capital Stack

The deal is structured as a sequential-pay transaction. Principal is distributed A1 → A2 → A3 → M1 → B1 → B2 → B3. Losses are allocated in reverse sequential order (B3 → B2 → B1 → M1 → A3 → A2 → A1).

OC Validation: Total collateral balance at issuance: $480,856,235. Sum of offered tranche balances (A1–B3): $480,856,235. Initial OC: $0 — No initial overcollateralization. The tranches fully cover the collateral balance at issuance. Credit enhancement is provided entirely through subordination.

2b. Subordination Levels

TrancheBalanceCouponSub Below ($)Sub Below (%)Type
A1$296,688,0002.79%$184,168,23538.3%Senior
A2$32,458,0002.94%$151,710,23531.5%Senior
A3$61,790,0003.05%$89,920,23518.7%Senior
M1$32,457,0003.48%$57,463,23511.9%Mezzanine
B1$25,486,0003.99%$31,977,2356.6%Subordinate
B2$22,600,0004.92%$9,377,2351.9%Subordinate
B3$9,377,235SOFR+0bps$00.0%First Loss

Subordination % = balance of tranches junior to each class / total collateral balance.

2c. Key Structural Features

  • Payment Priority: Sequential interest (A1→B3), then scheduled principal, unscheduled principal, and recovery principal
  • Excess Turbo: Excess spread directed sequentially to pay down principal (A1→B3) before release
  • Excess Release: Residual excess spread released to XS, then R
  • Clean-Up Call: Optional redemption when pool balance falls below 10% of original balance
  • Triggers: 1 trigger (clean-up call only); no performance-based step-down triggers identified in the model

3. Collateral Analysis

3a. Pool Composition

CharacteristicDetail
Loan Count1,116
Issuance Balance$480,856,235
WAC Range4.375% – 10.375%
Fixed Rate43.9%
ARM56.1%
Lien Position100% First Lien
Delinquency at Cutoff100% Current

3b. Property Type

Type%
Single Family Detached52.1%
Planned Unit Development34.7%
2–4 Family6.6%
Condominium5.5%
Single Family Attached0.9%
Townhouse0.1%

3c. Occupancy & Purpose

Occupancy%
Owner-Occupied77.5%
Investment Property19.9%
Second Home2.6%
Loan Purpose%
Purchase58.9%
Cash-Out Refi31.7%
Rate/Term Refi9.4%

3d. Employment Type

Employment%
Self-Employed60.5%
Salaried/Wage Earner25.9%
Unknown13.6%

3e. Key Risk Factors

  • Self-Employed Concentration (60.5%): The dominant risk driver. Bank statement and alternative documentation borrowers exhibit materially higher default rates than full-doc borrowers, particularly in economic downturns. Primary basis for NQM multiplier adjustments.
  • Investment Property Exposure (19.9%): Non-owner-occupied properties have higher default propensity and lower recovery rates in distress scenarios.
  • ARM Exposure (56.1%): Rate reset risk on ARM collateral could elevate defaults if rates rise materially at reset dates.
  • Cash-Out Refinance (31.7%): Higher LTV at origination relative to rate/term refis; reduced equity cushion.
  • No Initial OC: The deal relies entirely on subordination for credit enhancement with no excess collateral buffer at issuance.

4. Historical Performance (Empirical Benchmarks)

4a. Matched Deal Universe

The empirical engine matched 10 comparable deals (avg FICO 706, avg rate 6.0%) drawn from Freddie Mac SFLLD data across vintages 2010–2025. Seasoning ranges from 8 months (2025 vintage) to 188 months (2010 vintage).

Important Caveat: The matched deals are agency (Freddie Mac) collateral used as a proxy for NQM performance. Agency SFLLD data reflects full-documentation, conforming borrowers. NQM/non-QM collateral — particularly self-employed, bank statement, and investment property loans — exhibits materially higher default rates and severity. NQM multiplier adjustments are applied in Section 5.

4b. Empirical CNL Milestones (Agency Proxy)

MonthCNLCDR (Ann.)SeverityVPR (CPR)
12M0.00%1.00%25.00%3.42%
24M0.01%1.00%25.00%10.50%
36M0.03%1.00%25.00%17.70%
48M0.10%1.00%38.28%14.00%
60M0.15%1.00%31.06%10.09%

Source: 10 matched deals, 119 months of CDR data, 113 months of severity data. These are historical observations, not projections.

Key Observations

  • Agency CDR is flat at 1.00% annualized throughout — consistent with high-quality conforming collateral
  • Severity rises from 25% in early periods to ~38% at 48 months, reflecting liquidation timing
  • VPR peaks at ~17.7% at 36 months, consistent with refinancing activity in the 2018–2022 rate environment
  • CNL through 60 months is only 0.15% for agency collateral — NQM adjustments are critical

5. Loss & Prepay Forecast

5a. NQM Adjustment Framework

The agency SFLLD data serves as a base proxy. Per the empirical engine's NQM adjustment guidance, the following multipliers are applied:

MetricSFLLD Agency BaseNQM MultiplierNQM AdjustedRationale
CDR1.00%×5.05.00%Alt-doc/bank stmt; 60.5% self-employed; investment property
CPR12.03% avg×0.6~7.2% avgLimited refi access for NQM borrowers
Severity28.30% avg×1.5~42–57%Higher LTV, less MI, investment property discounts
The base scenario cashflows were projected using the unadjusted agency curves. The NQM-adjusted assumptions represent the analytically appropriate stress case for this collateral type. Bond analytics in Section 7 reflect the base (agency proxy) scenario; a full NQM stress run would require re-projection with the adjusted curves.

5b. Base Scenario Curve Assumptions

CurveAverageRangeData Basis
CDR1.00%[1.00%, 1.00%]119 months empirical, 10 deals
CPR12.03%[0.66%, 21.31%]10 similar deals
Severity28.30%[25.00%, 38.28%]113 months empirical, 10 deals

5c. Projected vs. Empirical CNL Comparison

MilestoneAgency Empirical CNLBase Projected CNLNQM Stress Estimate
12M0.00%~0.00%~0.05%
24M0.01%~0.01%~0.20%
36M0.03%~0.03%~0.50%
48M0.10%~0.10%~1.20%
60M0.15%~0.15%~2.00%

NQM stress estimates are indicative based on ×5 CDR and ×1.5 severity multipliers; not model-computed.

6. Breakeven Loss Analysis

6a. Subordination-Based Breakeven

TrancheBalanceCredit Support (Sub Below)Breakeven CNL (Est.)Base CNL (60M)Cushion (vs. Base)
A1$296,688,00038.3%~38.3%0.15%>100×
A2$32,458,00031.5%~31.5%0.15%>100×
A3$61,790,00018.7%~18.7%0.15%>100×
M1$32,457,00011.9%~11.9%0.15%~79×
B1$25,486,0006.6%~6.6%0.15%~44×
B2$22,600,0001.9%~1.9%0.15%~13×
B3$9,377,2350.0%0.0%First Loss

Breakeven CNL ≈ credit support percentage. Cushion = Breakeven CNL / Projected Terminal CNL (base 60M = 0.15%).

Under the base (agency proxy) scenario: All tranches A1 through B2 have substantial cushion (13× to >100×) against the 0.15% projected 60-month CNL. B3 is the first-loss piece with no protection.

Under NQM stress (CDR ×5, severity ×1.5): Terminal CNL could reach 2–4% over the life of the deal. Even under this scenario, A1–B1 retain meaningful cushion. B2 (1.9% breakeven) would be at risk if NQM-adjusted losses approach or exceed 2%. B3 would absorb first losses immediately.

Key Conclusion: The senior tranches (A1–A3) are well-protected even under severe NQM stress scenarios. The B2 tranche represents the marginal credit risk position in a stress environment.

7. Waterfall & Tranche Analytics

7a. Waterfall Results (Base Scenario)

All offered tranches fully amortize under the base scenario with no principal shortfall:

TrancheOpening BalanceClosing BalanceShortfall
A1$296,688,000$0None
A2$32,458,000$0None
A3$61,790,000$0None
M1$32,457,000$0None
B1$25,486,000$0None
B2$22,600,000$0None
B3$9,377,235$0None
XS$480,856,235$281,234,334YES (by design)
AIOS$480,856,235$480,856,235YES (by design)
The XS and AIOS shortfalls are structural — XS is a cap funds reserve/excess spread vehicle and AIOS is a reference notional class. These are not credit impairments.

7b. Bond Analytics (Base Scenario, Price = 100.00)

TranchePriceYieldWALNotes
A1100.0015.88%4.21yShort WAL; high yield reflects excess spread capture
A2100.0017.19%4.21yCo-sequential with A1
A3100.0018.09%4.21yCo-sequential with A1/A2
M1100.009.61%12.96yMezzanine; extends significantly
B1100.0010.71%16.38ySubordinate; long extension
B2100.0014.75%21.28yDeep subordinate; very long WAL
B3100.00-3.22%0.00yFirst loss; negative yield reflects SOFR+0 coupon vs. loss absorption
XS100.00-14.74%6.01yExcess spread vehicle; negative yield expected
WAL Test Note: The model flagged 42 of 48 WAL tests as failed (RMSE: 4.10 years). The computed WALs for senior tranches are shorter than prospectus benchmarks (e.g., A1 computed 4.21y vs. expected 17.72y at 0% ABS). This discrepancy is consistent with the base CDR/CPR assumptions (agency proxy, unadjusted) producing faster-than-expected paydown. The NQM-adjusted curves (CDR ×5, slower CPR) would extend WALs toward prospectus benchmarks. Analytics should be interpreted with this calibration caveat in mind.

Yield Observations

  • The unusually high yields on A1–A3 (15–18%) at par reflect the model's fast-prepay base case, which compresses WAL and front-loads cashflows to senior tranches
  • M1 and B1 yields (9.6–10.7%) are more consistent with mezzanine NQM pricing
  • B3's negative yield confirms its first-loss/residual character

8. Purchase Recommendation

No specific tranche or price target was provided in the request. The following reflects a general framework based on the analytics.

Senior Tranches (A1–A3): At par (100.00), the model-implied yields of 15–18% are likely overstated due to the fast-prepay base case. Under NQM-adjusted assumptions (slower CPR, higher CDR), WALs would extend and yields would compress. These tranches carry strong credit protection (18–38% subordination) and are appropriate for investment-grade buyers. Recommend further analysis with NQM-calibrated curves before pricing.

Mezzanine (M1): 9.61% yield at 100.00 with 12.96y WAL and 11.9% credit support. Reasonable risk/return for NQM mezzanine exposure. B2 breakeven (1.9%) provides a meaningful buffer above M1.

B2 Tranche: 14.75% yield at 100.00 with 21.28y WAL and only 1.9% credit support. Under NQM stress (terminal CNL 2–4%), this tranche is at risk of impairment. Not recommended at par without significant price discount.

B3 (First Loss): Negative yield at par; appropriate only for residual/equity investors with full understanding of first-loss exposure.

9. Key Risks

9a. Collateral/Credit Risks

RiskSeverityDetail
Self-Employed ConcentrationHIGH60.5% of pool; bank statement/alt-doc borrowers have 3–5× higher default rates in stress
Investment Property ExposureMEDIUM-HIGH19.9% of pool; higher default propensity and lower recovery rates
NQM Proxy LimitationHIGHEmpirical benchmarks are agency data; actual NQM performance could be 3–5× worse on CDR
ARM Reset RiskMEDIUM56.1% ARM collateral; rate resets could elevate defaults
Cash-Out Refi ConcentrationMEDIUM31.7% cash-out refis; higher LTV, reduced equity cushion

9b. Structural Risks

RiskDetail
No Initial OCZero overcollateralization; all CE is subordination-based
No Performance TriggersNo step-down or performance-based triggers; subordination cannot build through OC accumulation
WAL Model Calibration42/48 WAL tests failed; base scenario uses agency proxy curves that understate NQM risk
B3 SOFR+0 CouponFloating rate first-loss; in rising rate environment, coupon increases without collateral benefit

9c. Macro/Rate Sensitivity

RiskDetail
Home Price Decline10–15% HPA decline would push severity from ~28% toward 40–50%, impacting B2 and B3
Unemployment ShockSelf-employed borrowers disproportionately affected; recession could push CDR to 5–8% (NQM-adjusted)
Interest Rate ExtensionUnder NQM-adjusted slow CPR (~7%), WALs for M1–B2 extend to 15–25 years
Prepayment Lock-InNQM borrowers have limited refi access; CPR may not accelerate even if rates decline
Rate Shock (–200bps)CPR response muted (~×0.6 multiplier) vs. agency; limited WAL compression

9d. Data & Model Caveats

  • No loan tape provided: Collateral stratification (FICO distribution, LTV, state concentration) could not be independently verified. Characteristics sourced from prospectus supplement.
  • Agency proxy for NQM: The 10 matched deals are all Freddie Mac conforming pools. NQM-specific empirical data was not available in the matched set.
  • WAL calibration failure: The base scenario WAL tests failed significantly, indicating the model requires NQM-adjusted curves for accurate analytics. All yield/WAL figures should be treated as indicative pending recalibration.
  • AIOS/R analytics unavailable: AIOS pricing failed due to settle date mismatch; R tranche has no cashflows in the model.

This report was generated using empirical data from 10 matched agency deals (Freddie Mac SFLLD, vintages 2010–2025) as a proxy for NQM collateral performance. All projected figures are model outputs and should not be relied upon as investment advice. NQM multiplier adjustments (CDR ×5, severity ×1.5, CPR ×0.6) are recommended before finalizing tranche analytics.

IC Report on NQM Securitization — Graam