Financial Services Case Interview: Banking, Insurance, Fintech, and Worked Examples (2026)

Financial-services cases change with the institution: banks start with NII and fees, insurers with premiums and combined ratio, and fintechs with transaction economics. A recommendation must respect the regulatory, balance-sheet, and risk constraints of the specific institution.

Financial services cases punish candidates who treat banks like consumer goods companies. The business models, cost structures, and growth levers are fundamentally different.

How Financial Institutions Actually Make Money

The four major financial-services subsectors have different economic models. Use this selector before choosing a framework or practice route:

Bank Revenue Deep Dive

When a retail bank's profitability is declining, decompose revenue into three streams:

Net Interest Income (NII) = Interest earned on loans − Interest paid on deposits

The share of revenue from NII varies by bank and period. Diagnose it from the case data or current filings. NII is driven by:

• Loan volume (more loans = more interest income)
• Loan yield (higher interest rates on loans = higher income)
• Deposit cost (lower rates paid on deposits = higher spread)
• Net interest margin (NIM) = NII ÷ average earning assets

In rising interest rate environments, banks typically benefit from NII expansion (loan rates reset faster than deposit rates). In falling rate environments, the spread compresses.

Fee Income = Wealth management fees + transaction fees + advisory + card interchange

Fee income is the growth engine for most banks. It's not interest-rate sensitive and scales with customer relationships. Digital transformation cases often center on growing fee income through platform expansion.

Trading Income = Revenue from capital markets, derivatives, and proprietary investment

Most relevant for investment banks and larger commercial banks. High variance: can be negative in volatile markets.

The Financial Services Case Framework

Financial Services Case Framework

1. 01

   1. Revenue Decomposition. Split into NII, fee income, and trading income (banks) or premiums (insurance) or AUM fees (asset mgmt). What is growing vs. declining?

2. 02

   2. Cost Structure Analysis. Fixed costs (compliance, infrastructure, headcount) vs. variable costs (credit losses, claims). Which cost has grown faster than revenue?

3. 03

   3. Risk Exposure. Credit risk (loan defaults), market risk (rate/FX sensitivity), operational risk. What risk events are impacting performance?

4. 04

   4. Regulatory Environment. What capital requirements apply? What compliance costs are non-discretionary? Are regulatory changes creating or limiting strategic options?

5. 05

   5. Competitive Position. Market share vs. peers. Fintech disruption pressure. Customer segment share and attrition rates.

Worked Example: Digital Bank vs. Fintech Competition

Case prompt: A traditional regional bank with $50B in assets and $2.4B in annual revenue has seen its checking account customer base decline 8% over two years. A fintech competitor (similar to Chime or SoFi) has captured significant share in the 18–35 demographic. What should the bank do?

Step 1: Diagnose the problem

Revenue impact: Checking accounts generate fee income (monthly fees, overdraft fees, interchange on debit card spend). Each customer lost represents ~$150–200/year in fee income. At 8% loss from a 2 million customer base: 160,000 customers × $175/year = $28M annual revenue impact.

Step 2: Understand why customers are leaving

The fintech competitor offers:

• Zero monthly fees vs. bank's $12/month
• No minimum balance requirement
• Instant mobile account opening (no branch visit)
• Higher savings rates (4.5% APY vs. bank's 0.5%)

This is a product-market fit problem, not a marketing problem. The bank's product is structurally inferior for the digital-native customer segment.

Step 3: Strategic options

Step 4: Recommendation

Recommend a build + partnership hybrid: launch a digital sub-brand (18–24 months) while partnering with a white-label BaaS provider in the interim to capture at-risk customers. This addresses the urgent retention problem while building a sustainable long-term asset.

Quantify the payback: If the bank retains 60,000 of the 160,000 at-risk customers through the digital product, that's ~$10.5M in retained fee income annually. At a $25M investment in the digital sub-brand, payback is ~2.4 years.

Insurance Cases

Insurance profitability differs from banking. The key decomposition:

Combined Ratio = (Claims Paid + Operating Expenses) ÷ Premiums Earned

A combined ratio below 100% means the insurer is profitable on underwriting. Above 100% means they're paying out more in claims and expenses than they earn in premiums, and must rely on investment income to break even.

Property and casualty insurers use combined ratio, while life insurers use different metrics. Do not import one target range into a case without a named company, source, and period.

Combined-ratio practice rep

Assume an insurer earns $500M in premiums, pays $360M in claims, and incurs $115M in underwriting expenses. The combined ratio is ($360M + $115M) / $500M = 95%. Underwriting profit is $25M before investment income. If claims rise by $35M with premiums and expenses unchanged, the combined ratio becomes 102% and underwriting moves to a $10M loss. The decision is not simply to cut cost: test pricing, claim frequency, claim severity, mix, and the feasibility of repricing the affected segment.

Common insurance case types:

• Claims inflation eroding profitability (combined ratio rising)
• Entering a new insurance line (e.g., cyber insurance)
• Pricing a new risk category
• Distribution strategy (direct vs. agent vs. broker)

For a full breakdown of these scenarios with combined-ratio worked examples, see the dedicated insurance case interview guide.

Fintech Cases: Key Economics

Fintech cases usually involve a startup or growth-stage company with a CAC/LTV unit economics problem.

Key fintech metrics:

A fintech case is often a market entry question: "Should our client (a bank or investor) enter the BNPL (buy now, pay later) market?" The framework: market size + growth, competitive intensity, regulatory risk, unit economics, and client's capability to compete.

Connect to Broader Case Skills

Financial services cases still require core consulting fundamentals:

• Banking case interview for NII decomposition, deposit-franchise economics, and credit-risk cases at retail and commercial banks
• Profitability framework adapted for NII/fee/trading decomposition
• Market entry framework for new product or geography expansion
• M&A case framework for bank merger due diligence
• Digital transformation case interview for fintech and BaaS strategy
• Case interview math practice for spread, margin, and payback calculations
• Fintech case interview for BNPL, neobank, and digital payments cases that sit at the edge of traditional FS
• Real estate case interview for REIT, insurance real estate portfolio, and mortgage origination cases
• TMT case interview for cases involving financial data providers, trading platforms, and embedded finance in telecom billing

For firms that specialize in financial services consulting, Deloitte and PwC both have major financial services practices and regularly use industry-specific cases.

Sources and Further Reading (checked June 17, 2026)

• Hacking the Case Interview, Financial Services Guide: hackingthecaseinterview.com/pages/financial-services-case-interview
• Management Consulted, Financial Services Case Study: managementconsulted.com/financial-services-case-study-interview
• EY Global Financial Services Regulatory Outlook 2026: ey.com/en_gl/insights/financial-services
• MIT Technology Review, AI in Banking Survey, 2025: technologyreview.com
• Freshfields, Year Ahead in Financial Services 2026: freshfields.com/en/our-thinking/briefings/2026/01/the-year-ahead-in-financial-services