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DESK 05 // COMMERCIAL BANKING & CREDIT • 5 ACTIVE MODELS

Banking & Credit Underwriting Desk

Regulatory bank capital adequacy under Basel III, commercial debt service coverage ratio (DSCR) underwriting, Small Business Administration (SBA 7a vs 504) loan comparison, and commercial rate cap hedging. Built for chief credit officers, commercial lenders, and business borrowers.

Bank Capital & ALM Stress

Bank Balance Sheet, Capital & Basel III ALM Underwriter

Deterministic bank asset-liability management (ALM) and regulatory capital stress-tester. Quantify duration gaps, Net Interest Margin (NIM) sensitivity, Common Equity Tier 1 (CET1), Supplementary Leverage Ratio (SLR), Liquidity Coverage Ratio (LCR), and deposit run liquidity cushions.

• Balance Sheet ALM Duration Gap: Delta E = -[D_A - (L/A)D_L] * A * Delta y
• Basel III Regulatory Capital Ratios: CET1, Tier 1, Total Capital & SLR
• Liquidity Coverage Ratio (LCR) & 30-Day Net Cash Outflow Solver
• 4-Tier Deposit Run Contagion Stress-Test (5% to 25% Outflow)
• Regional Bank (SVB-style) vs. G-SIB Balance Sheet Presets
Launch ALM Underwriter →
Commercial Underwriting

Commercial Debt Service Coverage Ratio (DSCR) Underwriter

Dual-mode credit committee underwriter. Solve for debt coverage and test against revenue & interest rate shocks, or solve backwards to calculate maximum borrowing capacity.

• Mode A: Assess DSCR & Cash Flow Cushion
• Mode B: Max Allowable Debt Capacity Solver
• Bank Approval Verdict (Approved / Conditional / Stressed)
• Dual Revenue & Rate Sensitivity Stress Matrix
Launch Underwriter →
SBA & Bank Facilities

SBA 7(a) vs. SBA 504 vs. Conventional Underwriter

Direct side-by-side cost and debt service comparison across the three primary commercial debt instruments. Calculates tiered SBA guaranty fees, blended rates, and total interest.

• SBA 7(a) Variable Loan (Prime + Spread)
• SBA 504 Two-Tier Debenture (25Y Fixed Rate)
• Conventional Commercial Bank Loan with Balloon
• Statutory SBA SOP Tiered Guaranty Fee Schedule
Launch Underwriter →
Debt Amortization & Floating Stress

Commercial Loan Amortization & Prime Rate Stress-Tester

Deterministic commercial loan amortization and floating rate stress-tester. Model monthly debt service, principal retirement waterfalls, balloon refinancing payoffs, and Prime/SOFR rate shocks (+/- 50 to 300 bps) against commercial bank DSCR covenants.

• Live WSJ Prime & 30-Day SOFR Borrowing Benchmark Hydration
• Floating Spread vs. Conventional Fixed Rate Modes
• Mismatched Balloon Maturity Balances (5Y, 7Y, 10Y Balloon)
• 8-Tier Interest Rate Shock Sensitivity Matrix (-100 to +300 bps)
• Year-by-Year Debt Service Amortization Schedule Table
Launch Amortization Engine →
Commercial Rate Hedging

Commercial Floating Rate Cap & Interest Rate Swap Underwriter

Underwrite commercial debt hedging structures. Compare upfront cash rate caps against zero-cost floating-to-fixed interest rate swaps (SOFR and WSJ Prime). Model lender escrow requirements, monthly counterparty recoveries, 6-scenario rate shock sensitivity, and Mark-to-Market (MtM) early loan prepayment breakage penalties.

• Upfront Cap Strike Insurance Pricing & Monthly Payoff Recovery
• Zero-Cost Floating-to-Fixed SOFR Swap Lock Structuring
• 6-Scenario Macro Interest Rate Shock Matrix (-200 to +300 bps)
• Breakeven Benchmark Rate & Cap Premium Amortization Solver
• Early Prepayment Mark-to-Market (MtM) Breakage Fee Estimator
Launch Hedging Underwriter →

Banking & Credit Underwriting Desk Quantitative Architecture & Methodology

The Banking & Credit Underwriting Desk reflects the institutional underwriting standards enforced by commercial banks and regulatory authorities (OCC, FDIC, Federal Reserve). Models enforce Basel III risk-weighted asset (RWA) limits and commercial loan covenants.

Core Mathematical Formulations

Common Equity Tier 1 (CET1) Ratio Mathematical Proof
$$\text{CET1 Ratio} = \frac{\text{CET1 Capital}}{\text{RWA}} \ge 4.5\% + \text{Buffer}$$

The primary regulatory measure of a bank's financial strength and capacity to absorb unexpected loan losses without insolvency.

Debt Service Coverage Ratio (DSCR) Mathematical Proof
$$\text{DSCR} = \frac{\text{Net Operating Income}}{\text{Annual Debt Service}} \ge 1.25x$$

The standard cash flow coverage test verifying whether commercial operating income is sufficient to service mandatory principal and interest payments.

Cash Conversion Cycle (CCC) Mathematical Proof
$$\text{CCC} = \text{DSO} + \text{DIO} - \text{DPO}$$

Quantifies the exact time in days required for a company to convert operating investments into cash inflows, driving working capital loan sizing.

Commercial Rate Cap Hedging Mathematical Proof
$$\text{Payoff}_t = \max(0, \text{Benchmark}_t - \text{Strike}) \times \text{Notional} \times \frac{\text{Days}}{360}$$

Structures interest rate cap corridors protecting commercial borrowers against sharp SOFR spikes on floating-rate debt.

Target Institutional Audience & Applications

Commercial Bank Credit Officers

Senior underwriters verifying commercial DSCR coverage, collateral advance rates, and regulatory Basel III capital allocation.

Small Business Borrowers

Entrepreneurs and CFOs comparing SBA 7(a) vs. CDC/504 vs. conventional bank debt to minimize down payments and financing costs.

Commercial Loan Brokers

Financial intermediaries packaging multi-million dollar credit requests for bank and non-bank direct lending approval.

Cross-Asset Concept Guides & Recommended Reading