Banking And Finance Mathematics | Bank Balance Sheets, Net Interest Margin, Leverage and Profitability

A bank balance sheet is a mathematical machine for transforming funding into assets while preserving accounting identity, liquidity, capital and profitability constraints. Assets include loans, securities, cash and other claims. Liabilities include deposits, wholesale funding and other obligations. Equity absorbs residual gains and losses. Net interest income, net interest margin, return on assets, return on equity, leverage, provisions, fee income and operating costs describe how that balance sheet earns—or fails to earn—through time.

For readers searching for bank balance sheet mathematics, bank assets and liabilities, net interest margin formula, NIM, net interest income, return on assets, ROA, return on equity, ROE, bank leverage, deposit funding, bank profitability, earning assets, cost of funds, asset yield, bank balance sheet example or banking ratios, the governing identity is familiar: Assets = Liabilities + Equity. But banking becomes interesting because nearly every line is interest-rate-sensitive, maturity-sensitive, credit-sensitive or liquidity-sensitive.

Current official banking material uses the same core ratios. The U.S. Federal Reserve’s June 2026 supervision report defines net interest margin as net interest income relative to average interest-earning assets, ROAA as net income divided by average assets and ROE as net income divided by average equity capital. Its 2026 funding-shock analysis also shows why NIM depends on how asset yields and funding costs reprice. These are useful global reference points for the mathematics. This page is educational, not banking, investment or accounting advice.

50-Second Router

• Balance-sheet identity: assets equal liabilities plus equity.
• Earning assets: loans and securities that generate interest or yield; cash and reserves may earn differently depending on the system.
• Net interest income: interest income minus interest expense.
• NIM: net interest income divided by average earning assets, usually annualised under the reporting convention.
• ROA/ROAA: net income relative to average total assets.
• ROE: net income relative to average equity.
• Leverage: small equity supports a much larger asset base, magnifying both returns and losses.
• Cost of funds: weighted cost of deposits, wholesale debt and other interest-bearing funding.
• Asset yield: interest income relative to average earning assets or a defined asset base.
• Profitability: NIM is important, but fees, provisions, trading income, operating cost and taxes also matter.
• Risk: balance-sheet growth can raise earnings while simultaneously increasing credit, liquidity, capital and interest-rate risk.
• Verification: every ratio must reconcile to the accounting statements and use compatible average versus period-end denominators.

The Central Proposition: Banking Is a Constrained Balance-Sheet Transformation

A bank takes funding from depositors, creditors and shareholders and transforms it into loans, securities, liquidity reserves and other assets. The accounting identity always closes: if assets rise by S$100 and no liability changes, equity must rise by S$100; if a new S$100 deposit arrives and remains as cash, both assets and liabilities rise by S$100.

Profitability emerges from the rates, fees, losses and costs attached to those positions. A loan may earn 5%, a deposit may cost 2%, wholesale funding may cost 4%, and liquid securities may earn less than loans but serve liquidity or regulatory purposes. The bank cannot maximise yield without limit because it must also manage default risk, liquidity, capital, concentration, optionality and operational constraints.

Adrian’s first question is therefore not “how much profit does the bank make?” but “what balance-sheet positions generate the profit, how are they funded, and what risks are being taken to produce it?” That question turns ratios into a system rather than a scoreboard.

1. Assets

Assets is economic resources and financial claims controlled by the bank, including loans, securities, cash and other receivables. Assets are where most earning and credit risk reside. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Assets=Loans+Securities+Cash+OtherAssets in a simple decomposition. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Treating every asset as equally liquid or equally risky ignores the central economics of banking. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into balance sheet and RWA. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

2. Liabilities

Liabilities is obligations owed to depositors, creditors and other counterparties. They provide most of a bank’s funding. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Liabilities=Deposits+WholesaleFunding+OtherLiabilities in a simple map. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Calling deposits ‘bank assets’ reverses the bank’s perspective: customer deposits are generally liabilities of the bank. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into funding and liquidity. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

3. Equity

Equity is the residual accounting claim after liabilities are subtracted from assets. It absorbs gains and losses before creditors under the capital structure. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Equity=Assets−Liabilities. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Book equity is not identical to regulatory CET1, tangible common equity or market capitalisation. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into capital. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

4. Balance-sheet identity

Balance-sheet identity is the accounting equality linking assets, liabilities and equity. Every transaction must preserve it. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. A=L+E. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. A model that grows loans without specifying the funding or equity counterpart is incomplete. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into bank simulation. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

5. Cash and reserves

Cash and reserves is highly liquid balances held to meet payments, settlement and liquidity needs. They provide resilience but can earn differently from loans. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Liquidity share=CashAndReserves/Assets under a simple ratio. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Calling all cash ‘idle’ ignores payment, settlement and prudential functions. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into liquidity. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

6. Loans

Loans is contractual claims on borrowers generating principal and interest cash flows. They are often a major earning-asset category and credit-risk source. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Loan interest income≈average loan balance×effective yield in a simplified model. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Contractual coupon is not identical to realised loan yield after prepayment, nonaccrual and fees. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into credit and NIM. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

7. Securities

Securities is bonds and other investments held for liquidity, yield, collateral or market-making purposes. They can provide liquidity and duration exposure. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Security yield=interest/accretion income relative to average security balance under the chosen accounting view. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Market value and accounting carrying value can differ. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into rate risk. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

8. Earning assets

Earning assets is assets included in the denominator of NIM because they generate interest or yield under the reporting convention. They connect balance-sheet composition to interest income. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. NIM=NII/AverageEarningAssets. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Using total assets instead of earning assets changes the ratio and comparability. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into NIM. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

9. Deposits

Deposits is customer balances owed by the bank. They can be stable funding and a major source of franchise value. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Deposit cost=deposit interest expense/average interest-bearing deposits under a simple measure. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Non-interest-bearing and interest-bearing deposits should not be merged blindly when analysing rate sensitivity. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into funding. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

10. Non-interest-bearing deposits

Non-interest-bearing deposits is deposit balances that pay no explicit interest under the product terms. They can lower average funding cost while still requiring service and liquidity capacity. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Explicit rate=0, but total economic cost is not zero because servicing and franchise costs exist. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Assuming zero explicit interest means zero funding value/cost is too simplistic. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into deposit beta. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

11. Interest-bearing deposits

Interest-bearing deposits is deposits that pay contractual interest. Their repricing speed and customer sensitivity shape NIM. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Cost≈interest expense/average balance. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Advertised rates, realised average rates and marginal new-money rates can differ. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into NIM. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

12. Wholesale funding

Wholesale funding is funding from interbank, bond, repo or institutional markets. It can diversify funding but may be more market-sensitive and less sticky than retail deposits. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Weighted funding cost includes wholesale rates and fees. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Short-term wholesale funding can disappear or become expensive in stress. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into liquidity. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

13. Secured funding

Secured funding is borrowing backed by collateral such as securities. It links funding capacity to collateral value and haircuts. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. BorrowableAmount≈CollateralValue×(1−Haircut) in a toy model. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Collateral prices and haircuts can deteriorate together under stress. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into repo. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

14. Unsecured funding

Unsecured funding is borrowing without pledged collateral. It depends strongly on creditor confidence and credit spreads. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Funding cost=benchmark+credit/liquidity spread. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. A solvent bank can still face high unsecured funding costs if confidence weakens. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into liquidity. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

15. Net interest income

Net interest income is interest income earned on assets minus interest expense paid on funding and other interest-bearing liabilities. It is the numerator of NIM and a central banking earnings component. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. NII=InterestIncome−InterestExpense. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. NII in currency and NIM in percentage answer different questions. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into profitability. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

16. Net interest margin

Net interest margin is net interest income relative to average earning assets under the reporting convention. It normalises interest earnings by the balance sheet that produces them. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. NIM=NII/AverageEarningAssets. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Comparing NIM across banks with different business models requires care because asset mix differs. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into profitability. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

17. Asset yield

Asset yield is interest income divided by average earning assets or a specified asset class. It measures gross yield before funding cost. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. AssetYield=InterestIncome/AverageEarningAssets. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Asset yield can rise while profitability falls if funding costs rise faster. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into NIM. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

18. Funding cost

Funding cost is interest expense relative to average interest-bearing liabilities or another defined funding base. It measures explicit cost of borrowed/deposit funding. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. FundingCost=InterestExpense/AverageInterestBearingLiabilities. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Funding cost depends on denominator definition and excludes non-interest costs unless added. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into NIM. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

19. Spread

Spread is difference between asset yield and funding cost under a simplified comparable basis. It gives intuitive intermediation economics. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Spread≈AssetYield−FundingCost. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. NIM is not exactly the simple spread when earning assets and interest-bearing funding differ in size and composition. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into margin analysis. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

20. Deposit beta

Deposit beta is the fraction of benchmark-rate change passed through to deposit rates over a specified period. It links market rates to funding cost. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Beta≈ΔDepositRate/ΔBenchmarkRate. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Beta can vary by product, customer, direction and cycle. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into NIM sensitivity. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

21. Asset beta

Asset beta is the pass-through or repricing sensitivity of asset yields to benchmark changes. It determines how quickly interest income reacts. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. AssetBeta≈ΔAssetYield/ΔBenchmarkRate. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Fixed-rate loans can have low near-term beta even if new lending reprices quickly. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into rate sensitivity. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

22. Repricing gap

Repricing gap is difference between assets and liabilities that reprice within a chosen time bucket. It gives a simple earnings-at-risk view. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Gap_t=RateSensitiveAssets_t−RateSensitiveLiabilities_t. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. It ignores optionality, basis differences and behavioural deposit maturities. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into ALM. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

23. Maturity gap

Maturity gap is difference in timing structure between asset and liability cash flows. It is related to but not identical with repricing gap. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Compare weighted or bucketed maturity profiles. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. A long contractual deposit maturity can still reprice differently from a loan. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into liquidity and ALM. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

24. Net interest income sensitivity

Net interest income sensitivity is change in projected NII under an interest-rate scenario. It captures earnings effects over a horizon. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. ΔNII=ProjectedNII_shock−ProjectedNII_base. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. One-year NII sensitivity can disagree with long-run economic value sensitivity. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into IRRBB. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

25. Economic value of equity

Economic value of equity is present value of asset cash flows minus present value of liability cash flows under an economic valuation framework. It captures longer-horizon balance-sheet rate sensitivity. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. EVE=PV(A)−PV(L). Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Accounting equity and EVE are not identical concepts. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into interest-rate risk. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

26. Return on average assets

Return on average assets is net income divided by average assets. It measures profit earned per unit of bank asset base. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. ROAA=NetIncome/AverageAssets. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. A high ROAA can come with high risk; it is not a stand-alone safety measure. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into profitability. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

27. Return on equity

Return on equity is net income divided by average equity. It measures accounting return relative to shareholder capital. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. ROE=NetIncome/AverageEquity. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Higher leverage can raise ROE mechanically while weakening resilience. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into leverage. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

28. Equity multiplier

Equity multiplier is assets divided by equity. It shows balance-sheet leverage in a simple accounting sense. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. EquityMultiplier=AverageAssets/AverageEquity. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. It should not be confused with the Basel leverage ratio denominator and capital definitions. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into DuPont analysis. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

29. ROE decomposition

ROE decomposition is the identity linking ROA and leverage in a simplified setting. It shows how modest asset returns can become higher equity returns. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. ROE≈ROA×EquityMultiplier. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. The approximation depends on consistent average balances and definitions. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into profitability. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

30. Leverage

Leverage is use of debt/deposit funding to support assets beyond shareholder equity. It magnifies gains and losses on equity. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. If assets=10×equity, a 1% asset loss equals roughly 10% of equity before other effects. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Accounting leverage is not the same as regulatory leverage exposure. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into capital. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

31. Operating income

Operating income is revenues from net interest, fees, trading and other activities before specified expenses. It broadens profitability beyond NIM. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. OperatingIncome=NII+NonInterestIncome under a simplified map. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Bank business models with low NIM can still be profitable through fees or market activities. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into income statement. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

32. Non-interest income

Non-interest income is fees, commissions, trading and other revenues not classified as interest. It diversifies earnings sources but can be volatile. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. FeeIncome/Assets or /Revenue are common analytical ratios. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Calling all non-interest income ‘stable’ ignores cyclical and market components. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into profitability. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

33. Operating expense

Operating expense is staff, technology, premises, administration and other costs. It converts revenue into pre-provision profit. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. PreProvisionProfit≈Revenue−OperatingExpense. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Cost cutting that weakens controls can raise operational risk. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into efficiency. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

34. Efficiency ratio

Efficiency ratio is non-interest expense relative to a defined revenue base in common bank analysis. It measures cost intensity. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. EfficiencyRatio=NonInterestExpense/NetRevenue under a chosen definition. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Definitions vary across jurisdictions and institutions. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into cost management. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

35. Pre-provision net revenue

Pre-provision net revenue is revenue before credit-loss provisions and taxes after operating expenses under common stress-testing usage. It isolates core earning capacity before credit losses. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. PPNR≈NII+NonInterestIncome−NonInterestExpense. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. PPNR definitions should match the supervisory/reporting context. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into stress testing. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

36. Provision for credit losses

Provision for credit losses is income-statement charge recognising expected credit losses under the accounting framework. It links credit deterioration to earnings. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. PreTaxIncome falls as provision expense rises, all else equal. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Provision is not the same as write-off or regulatory capital. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into credit accounting. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

37. Charge-off

Charge-off is recognition that a receivable amount is uncollectible under accounting/policy rules. It reduces loan carrying value/allowance according to the framework. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. NetChargeOff=ChargeOff−Recoveries in a common bank metric. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Charge-off timing can lag economic default. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into credit loss. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

38. Allowance for credit losses

Allowance for credit losses is balance-sheet contra-asset allowance for expected credit losses under applicable accounting rules. It absorbs expected credit deterioration in carrying value. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. NetLoans=GrossLoans−Allowance in a simplified presentation. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Allowance is not cash and not the same as equity capital. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into credit accounting. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

39. Nonperforming loan

Nonperforming loan is a loan classified as nonperforming under relevant definitions. It indicates elevated credit stress and income-recognition changes. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. NPLRatio=NPLs/GrossLoans. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Definitions and cure rules vary. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into asset quality. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

40. Nonaccrual loan

Nonaccrual loan is a loan on which interest accrual is suspended under accounting/regulatory policy. It directly affects interest income. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Accrued interest may be reversed or limited under policy. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Contractual yield can overstate realised yield if nonaccrual rises. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into NIM. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

41. Loan loss rate

Loan loss rate is credit losses relative to average or beginning loans under a stated convention. It links asset quality to profitability. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. NetChargeOffRate=NetChargeOffs/AverageLoans. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Comparing rates requires matching annualisation and denominator conventions. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into credit performance. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

42. Fee margin

Fee margin is fee income relative to assets, customers or revenue depending on analysis. It can supplement NIM. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. FeeYield=FeeIncome/AverageAssets in a simple version. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Fee metrics are business-model dependent. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into profitability. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

43. Trading income

Trading income is mark-to-market and realised revenue from trading activity. It can be significant for market-making banks. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. TradingP&L depends on positions and market moves. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Volatile trading revenue should not be treated like contractual loan interest. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into market banking. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

44. Taxes

Taxes is income taxes reduce net income after pre-tax profitability. They affect ROA and ROE but not NIM directly. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. NetIncome=PreTaxIncome−Taxes. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Cross-country tax comparisons can distort bank profitability comparisons. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into profitability. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

45. Average balance

Average balance is mean balance over the reporting period used for flow-to-stock ratios. It improves matching between annual income flows and balance-sheet denominators. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. AverageAssets≈(Beginning+Ending)/2 in a simple approximation. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Using year-end assets with full-year net income can distort fast-growing banks. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into ROA. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

46. Period-end balance

Period-end balance is stock value at a reporting date. It is appropriate for balance-sheet identity and many capital/liquidity ratios. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Assets_t=Liabilities_t+Equity_t. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Mixing period-end and average balances without explanation can create false movements. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into reporting. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

47. Growth rate

Growth rate is percentage change in balance-sheet items across time. It helps separate margin effects from volume effects. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Growth=(X_t−X_{t−1})/X_{t−1}. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Fast growth can temporarily flatter ratios while embedding future credit or funding risk. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into strategy. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

48. Loan growth

Loan growth is increase in gross or net loan balances. It can expand interest income but consumes funding, capital and liquidity. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. ΔLoans must be funded by deposits, debt, asset sales or equity changes. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Growth is not automatically profitable if pricing does not cover risk and funding. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into bank strategy. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

49. Deposit growth

Deposit growth is increase in customer deposits. It can support asset growth and liquidity. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. DepositGrowth=(D_t−D_0)/D_0. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Fast deposit growth can be rate-sensitive ‘hot money’ rather than stable franchise funding. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into liquidity. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

50. Loan-to-deposit ratio

Loan-to-deposit ratio is loans relative to deposits. It is a simple funding-structure indicator. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. LDR=Loans/Deposits. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. A high or low LDR has no universal safe interpretation without liquidity and business context. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into funding. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

51. Securities-to-assets ratio

Securities-to-assets ratio is securities relative to total assets. It helps describe asset mix. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Securities/Assets. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Securities differ greatly in liquidity, duration and credit risk. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into asset mix. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

52. Cash-to-assets ratio

Cash-to-assets ratio is cash and highly liquid balances relative to assets. It measures one layer of liquidity. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Cash/Assets. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Liquidity cannot be summarised by cash alone because funding outflows and HQLA matter. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into liquidity. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

53. Interest-sensitive asset

Interest-sensitive asset is an asset whose yield or value changes with interest rates over the analysis horizon. It drives NII or EVE sensitivity. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Classify by next repricing date or market-value sensitivity. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Contractual maturity is not always repricing date. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into ALM. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

54. Interest-sensitive liability

Interest-sensitive liability is a liability whose cost or value changes with market rates over the horizon. Deposits and wholesale debt can reprice differently. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Classify by behavioural/contractual repricing. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Non-maturity deposits require behavioural assumptions. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into ALM. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

55. Fixed-rate loan

Fixed-rate loan is a loan with contractual interest rate fixed for a specified period. It creates slower asset-yield repricing and market-value duration. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Cash flows can be discounted to measure EVE sensitivity. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Prepayment can shorten effective duration. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into loan book. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

56. Floating-rate loan

Floating-rate loan is a loan whose coupon resets to a benchmark plus spread under contractual rules. It reprices faster but can transfer rate risk to borrowers. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Coupon_t=Benchmark_t+Spread subject to terms. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Borrower credit risk may rise when benchmark rates increase. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into loan book. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

57. Fixed-rate deposit

Fixed-rate deposit is a deposit whose rate is fixed for its term. It locks funding cost for the period. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Interest expense=principal×contractual rate under a simple model. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Early withdrawal options can alter effective maturity. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into funding. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

58. Non-maturity deposit

Non-maturity deposit is deposit without contractual maturity such as current/savings balances. It requires behavioural assumptions for repricing and stability. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Model beta, decay and effective duration. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Treating all balances as overnight can overstate funding sensitivity; treating them as permanent can understate it. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into ALM. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

59. Deposit franchise

Deposit franchise is the economic value of a stable customer funding base. It can lower funding cost and support liquidity The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Franchise value is modelled through expected future spread/service relationships. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. It is not a balance-sheet asset recognised identically across accounting frameworks. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into bank valuation. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

60. Cost of deposits

Cost of deposits is interest expense and potentially associated servicing/economic costs relative to deposits. It shapes funding economics. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. ExplicitCost=DepositInterestExpense/AverageDeposits. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. New-money offered rates can be much higher than average book cost. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into NIM. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

61. Marginal funding cost

Marginal funding cost is cost of raising one additional unit of funding now. It is more relevant for new-loan pricing than historical average funding cost. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. MFC=incremental all-in funding cost. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Using average deposit cost can underprice new lending when market funding rates have risen. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into loan pricing. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

62. Funds transfer pricing

Funds transfer pricing is internal pricing that assigns funding and liquidity costs/credits to business units and products. It separates customer margin from treasury interest-rate risk. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. LoanSpread=CustomerRate−FTP−ExpectedLoss−Costs−CapitalCharge in a simplified profitability view. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Poor FTP can make businesses appear profitable by borrowing cheap funding from the balance sheet implicitly. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into bank management. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

63. Matched-maturity FTP

Matched-maturity FTP is internal transfer pricing using a funding curve matched to product maturity/repricing characteristics. It aligns product economics with term funding cost. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. FTP rate comes from an internal curve at relevant tenor plus adjustments. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. A single overnight FTP rate underprices long fixed-rate assets. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into ALM. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

64. Liquidity premium

Liquidity premium is incremental internal or market cost associated with stable funding/liquidity needs. It can be embedded in FTP. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. FundingCost=ReferenceCurve+LiquidityPremium+CreditSpread in a stylised decomposition. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Liquidity premia can change sharply in stress. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into funding. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

65. Credit spread in loan pricing

Credit spread in loan pricing is compensation for expected and unexpected credit costs within the pricing framework. It links borrower risk to customer rate. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. RequiredSpread includes EL and capital cost components. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. A flat margin across borrowers ignores differentiated credit risk. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into loan pricing. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

66. Capital charge

Capital charge is required return/cost allocated to equity capital supporting an exposure. It links profitability to risk-weighted assets or economic capital. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. CapitalCost=AllocatedCapital×TargetROE. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Using only expected loss can make high-tail-risk products look too profitable. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into RAROC. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

67. RAROC

RAROC is risk-adjusted return on capital. It compares risk-adjusted earnings with capital allocated to the activity. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. RAROC=(Revenue−Funding−OperatingCost−ExpectedLoss)/EconomicCapital in a stylised form. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Definitions vary; compare only after standardising numerator and capital denominator. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into profitability. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

68. ROA versus ROE

ROA versus ROE is two profitability ratios with different leverage sensitivity. ROA focuses on asset productivity; ROE magnifies leverage effects. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. ROE≈ROA×Assets/Equity in a simplified identity. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. A bank can increase ROE by reducing equity without improving asset economics. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into leverage. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

69. NIM versus NII

NIM versus NII is percentage margin versus currency earnings. Volume growth can raise NII even if NIM falls. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. NII=NIM×AverageEarningAssets approximately under compatible annualisation. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. A falling NIM does not automatically mean falling NII if earning assets expand. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into earnings analysis. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

70. Volume effect

Volume effect is change in NII caused by balance growth or shrinkage. It separates quantity from price/margin. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. ΔNII≈RateEffect+VolumeEffect+Interaction. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Attribution depends on chosen decomposition method. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into earnings. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

71. Rate effect

Rate effect is change in NII caused by yields/funding rates changing on existing balances. It separates repricing from balance growth. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Approximate rate effect=AverageBalance×ΔRate. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Balances themselves often respond to rates, creating interaction. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into NIM. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

72. Mix effect

Mix effect is earnings impact from changing composition across assets or funding sources. It explains why average rates move even if product-level rates are unchanged. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Weighted average yield changes as portfolio weights change. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Calling all margin change a ‘rate move’ can miss strategic balance-sheet shifts. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into management. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

73. Interest-rate floor

Interest-rate floor is contractual minimum rate on a floating asset or liability. It creates nonlinear repricing. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Coupon=max(Floor,Benchmark+Spread) in a simple case. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Linear beta assumptions fail near floors. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into optionality. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

74. Deposit floor

Deposit floor is practical or contractual lower bound on deposit pricing. It can compress NIM when market rates become very low. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Deposit rate may not fall below zero or another floor. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. The floor makes deposit beta asymmetric across hiking and cutting cycles. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into NIM. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

75. Prepayment option

Prepayment option is borrower right or ability to repay early. It changes loan cash-flow timing and reinvestment risk. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Effective duration depends on prepayment behaviour. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Ignoring prepayment can overstate future high-coupon income when rates fall. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into mortgage banking. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

76. Early withdrawal option

Early withdrawal option is depositor ability to break or withdraw funding before contractual term, sometimes with penalty. It shortens effective liability maturity. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Behavioural outflow differs from legal maturity. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Treating every fixed deposit as perfectly locked can overstate funding stability. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into liquidity. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

77. Duration gap

Duration gap is difference between interest-rate sensitivity of assets and liabilities after scaling. It links the balance sheet to EVE risk. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. DGAP=D_A−(L/A)D_L. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. NIM risk and EVE risk can point in different directions. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into ALM. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

78. Basis risk

Basis risk is risk that asset and liability reference rates do not move together. It survives matched repricing dates. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Asset may reprice to SORA while funding references deposit competition or another curve. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Gap analysis alone cannot capture reference-rate divergence. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into NIM. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

79. Yield-curve risk

Yield-curve risk is risk from nonparallel moves across maturities. It affects assets and liabilities differently based on tenor. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Use key-rate sensitivity or scenario curves. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. One average duration or gap can hide steepener/flattener exposure. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into ALM. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

80. Option risk

Option risk is risk from customer or issuer options changing cash flows with rates. It makes effective maturity endogenous. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Use behavioural and option-aware scenarios. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Static contractual schedules can misstate both NII and EVE. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into IRRBB. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

81. Liquidity risk

Liquidity risk is risk that the bank cannot meet cash outflows without unacceptable loss. It constrains balance-sheet composition independently of profitability. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Liquidity position compares liquid resources with stress outflows. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. A high NIM funded by unstable short-term money can be fragile. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into LCR and NSFR. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

82. Credit risk

Credit risk is risk of borrower nonpayment or deterioration. It converts earning assets into provisions, charge-offs and capital needs. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. EL=PD×LGD×EAD in a simple model. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. High loan yields can simply compensate for higher expected losses. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into credit risk. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

83. Capital constraint

Capital constraint is requirement that risk-taking be supported by eligible capital relative to regulatory or internal exposure measures. It limits balance-sheet growth. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. CapitalRatio=Capital/RWA. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Maximising ROE by shrinking capital conflicts with prudential constraints. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into CET1. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

84. Liquidity constraint

Liquidity constraint is requirement to maintain enough liquid assets and stable funding. It limits maturity transformation and asset composition. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. LCR and NSFR are major Basel ratios. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. A balance sheet can be well-capitalised but illiquid. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into liquidity. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

85. Profitability-resilience trade-off

Profitability-resilience trade-off is the tension between higher-yield/risk positions and buffers that reduce near-term return. It is central to banking strategy. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Optimisation is constrained by capital, liquidity, credit and risk appetite. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Calling low-yield liquidity assets ‘inefficient’ ignores their insurance function. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into bank management. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

86. Stress NIM

Stress NIM is net interest margin under a defined adverse funding and rate scenario. It evaluates earnings resilience. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. NIM_stress=(InterestIncome_stress−InterestExpense_stress)/AverageEarningAssets_stress. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Static balance assumptions can understate deposit runoff and funding substitution. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into stress testing. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

87. Funding shock

Funding shock is scenario in which deposit outflows or funding spreads rise. It can reduce NIM and force asset/liability changes. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Replace lost deposits with more expensive funding and reproject NII. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Funding shocks can interact with security sales, losses and capital. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into resilience. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

88. Deposit runoff

Deposit runoff is withdrawal of deposits over a period. It reduces liabilities but also forces cash use or replacement funding. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Cash after runoff=Cash_before−Outflows+ReplacementFunding/AssetSales. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Runoff rates are behavioural and scenario-dependent. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into liquidity. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

89. Asset sale

Asset sale is conversion of securities or loans into cash. It improves immediate liquidity but can crystallise losses or reduce future income. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Cash proceeds=MarketPrice−transaction costs. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Selling long-duration assets after rate rises can realise losses. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into liquidity. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

90. Unrealised loss

Unrealised loss is decline in market value not yet realised through sale under a given accounting treatment. It can affect economic value and sometimes regulatory/accounting equity. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. MarketValue−CarryingValue. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Accounting classification determines reported treatment; economic sensitivity still exists. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into capital. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

91. Book value

Book value is accounting carrying amount under applicable rules. It is the basis of reported statements. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Book assets and liabilities close the accounting identity. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Book value is not automatically current market value. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into financial statements. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

92. Market value

Market value is price at which an asset/liability could be valued in a market or model. It is central to economic-value analysis. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. MV depends on discount rates, spreads and liquidity. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Illiquid positions may not have a directly observable executable price. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into EVE. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

93. Tangible common equity

Tangible common equity is a non-regulatory analytical measure focusing on common equity net of certain intangibles. It can be used as a loss-absorption lens. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. TCE ratio definitions vary by analyst. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. It is not synonymous with CET1. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into capital analysis. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

94. Market leverage ratio

Market leverage ratio is a market-based leverage measure comparing market capitalisation with liabilities plus market capitalisation in some research/reporting. It reflects investor valuation as well as balance-sheet liabilities. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. MLR=MarketCap/(MarketCap+BookLiabilities) under the Fed definition. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. It can move sharply with share price without any accounting balance-sheet change. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into market risk perception. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

95. DuPont-style bank analysis

DuPont-style bank analysis is decomposition of ROE into asset profitability and leverage. It reveals whether high ROE comes from better earnings or more leverage. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. ROE≈ROAA×EquityMultiplier. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Ignoring risk costs can make leverage-driven ROE look like operating excellence. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into profitability. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

96. Sustainable growth

Sustainable growth is the growth rate supportable by retained earnings and target capital under a simplified model. It links profitability, payout and capital. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. g≈ROE×RetentionRatio. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Regulatory capital, RWA mix and balance-sheet constraints make the simple formula incomplete. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into strategy. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

97. Dividend payout

Dividend payout is share of earnings distributed to shareholders. It trades current distributions against retained capital for growth/resilience. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Retention=1−Payout. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. High payout can constrain capital accumulation during rapid RWA growth. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into capital planning. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

98. Share buyback

Share buyback is repurchase of equity from shareholders. It reduces common equity and shares outstanding, subject to rules/approvals. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Equity decreases by repurchase amount in a simplified accounting view. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Buybacks can raise per-share metrics while reducing capital buffers. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into capital management. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

99. Franchise profitability

Franchise profitability is long-run earnings capacity from customers, products and funding relationships. It matters more than one quarter’s margin. The useful habit is to connect the ratio back to the balance-sheet line and cash flow that creates it.

Mathematics. Evaluate through-cycle NII, fees, losses and operating cost. Every ratio needs a numerator period, denominator basis and annualisation convention. Flow measures such as interest income should generally be matched with compatible average stock balances when the ratio is intended to represent yield or return over a period.

Failure mode. Short-term NIM maximisation can damage customer retention. Jo’s diagnostic is to reconstruct the ratio from the statement line items and ask whether a change comes from price/rate, volume, mix, credit loss or funding structure.

Connection. This feeds directly into strategy. Ryan would then shock the relevant rate, balance or loss assumption and re-run the balance sheet. The objective is a model where every profitability movement has an identifiable balance-sheet cause.

Worked Example 1: Build a Simple Bank Balance Sheet

Suppose a bank has S$600m of loans, S$250m of securities and S$150m of cash. Total assets are S$1,000m. It has S$700m deposits, S$220m wholesale funding and S$80m equity. Liabilities plus equity are 700+220+80=S$1,000m, so the accounting identity closes.

Now suppose the bank makes a new S$20m loan funded by a new S$20m deposit. Loans become S$620m; deposits become S$720m; total assets and liabilities/equity both become S$1,020m. Nothing about the transaction requires equity to change immediately.

But capital ratios may change because risk-weighted assets rise. Liquidity can also change because a loan may require more stable funding or produce less immediate liquidity than cash. The accounting identity is necessary, not sufficient, for bank safety.

Worked Example 2: Net Interest Income and NIM

Average earning assets are S$900m. Interest income is S$45m and interest expense is S$18m for the year. NII=45−18=S$27m. NIM=27/900=3.0%.

If earning assets grow to S$1.0bn and NIM falls to 2.8%, annualised NII can still rise to roughly S$28m. This shows why percentage margin and currency earnings need to be read together.

Conversely, a bank can report stable NIM while total NII falls if the earning-asset base shrinks.

Worked Example 3: Asset Yield and Funding Cost

A bank earns S$52m interest on average earning assets of S$1.0bn, for a 5.2% gross asset yield. It pays S$24m interest on S$800m average interest-bearing funding, for a 3.0% funding cost.

The simple yield-minus-funding-cost spread is 2.2%, but NIM is (52−24)/1,000=2.8%. The numbers differ because funding and earning-asset denominators differ and non-interest-bearing funding/equity support some earning assets.

This is why “loan yield minus deposit rate” is intuition, not the formal NIM formula.

Worked Example 4: Deposit Beta

A benchmark rate rises from 1% to 4%, a change of 300bp. A bank’s average rate on an interest-bearing savings portfolio rises from 0.5% to 2.0%, a change of 150bp. Simple cumulative deposit beta=150/300=50%.

If loan asset yields rise by 240bp over the same window, the asset pass-through exceeds the deposit pass-through, helping NIM initially, all else equal. Later, competitive repricing may lift deposit beta further and compress the benefit.

Deposit beta should therefore be measured through time, by product and by direction, not treated as one permanent constant.

Worked Example 5: ROAA and ROE

A bank earns S$12m net income on average assets of S$1.2bn and average equity of S$100m. ROAA=12/1,200=1.0%. ROE=12/100=12%. The equity multiplier is 1,200/100=12, and 1%×12=12%, matching the simplified DuPont relation.

If equity were only S$60m with the same assets and income, ROE would be 20%. Nothing about the asset profitability improved; leverage simply increased. That higher ROE would come with a thinner loss-absorption layer.

This is why bank profitability cannot be judged from ROE alone.

Worked Example 6: Provision Shock

A bank generates S$40m pre-provision pre-tax earnings. Normal provision expense is S$8m, giving S$32m before tax. In a downturn, provision rises to S$25m while operating earnings are unchanged. Pre-tax income falls to S$15m.

The balance sheet can therefore have a healthy NIM while net income collapses because credit costs rise. High asset yields can also coexist with high provisions if the lending book is risky.

A strong analysis separates core margin from credit cost rather than calling both “profitability”.

Worked Example 7: Funding Shock

A bank loses S$100m of deposits costing 1.5% and replaces them with wholesale funding costing 4.5%. Annual interest expense rises by roughly S$3m if balances are held constant and the replacement persists for a year.

On S$1bn of earning assets, that alone reduces NIM by about 30bp before behavioural responses. If the bank also sells securities at a loss or shrinks lending, earnings and capital can be affected through additional channels.

This simple example mirrors the mechanism studied in official 2026 funding-shock analysis: profitability changes through replacement funding cost and balance-sheet response.

Worked Example 8: Loan Growth and Capital

A bank has S$10bn assets, S$9.2bn liabilities and S$0.8bn equity. It plans S$1bn of new lending funded entirely by deposits. Accounting equity remains S$0.8bn at origination, while assets rise to S$11bn.

Simple accounting assets-to-equity leverage rises from 12.5× to 13.75×. Risk-weighted assets will also rise depending on loan risk weights. If earnings do not retain enough capital, regulatory capital ratios can fall.

Growth therefore consumes balance-sheet capacity even when it is profitable.

Worked Example 9: NIM Versus EVE

A bank funds five-year fixed-rate loans with sticky deposits whose rates reprice slowly. A sudden rate rise can initially improve NII if deposit costs lag, yet the market value of the fixed-rate loans falls. The one-year earnings view and the economic-value view can point in different directions.

This is why interest-rate risk in the banking book uses multiple metrics rather than one. A balance sheet can gain near-term margin while losing economic value.

Mira’s check is to ask whether the analysis is about next year’s income statement or the present value of all future cash flows.

Worked Example 10: Mix Shift

Suppose earning assets stay at S$1bn, but the bank shifts S$100m from 2% securities to 6% loans. Gross annual interest income rises by roughly S$4m before credit loss, capital, liquidity and operating effects.

On the surface, NIM improves by about 40bp if funding cost is unchanged. But the loan portfolio may consume more capital, require provisions and be less liquid. A complete profitability measure should include these costs.

The exercise demonstrates why balance-sheet optimisation is constrained: yield alone is not the objective.

The Income Statement Is the Time Dimension of the Balance Sheet

A balance sheet is a snapshot. The income statement records flows over a period. Interest income is generated by asset balances through time; interest expense is generated by funding balances through time; provisions reflect credit-loss expectations; fees and operating costs reflect customer and infrastructure activity.

This is why average balances matter. If assets grow from S$1bn to S$2bn during the year, dividing full-year income by S$2bn year-end assets understates the average return earned on the capital deployed through the year. A simple beginning/end average is better than period-end, and daily/monthly averages can be better still where available.

The mathematical principle is matching: flow numerator with the stock base that generated it.

Balance-Sheet Profitability Is a Decomposition Problem

When ROE changes, ask what changed in ROAA and what changed in leverage. When ROAA changes, separate NIM, fees, operating costs, provisions and taxes. When NIM changes, separate asset yield, funding cost, volume and mix. When funding cost changes, separate benchmark rates, deposit beta, deposit mix, wholesale spreads and customer behaviour.

This layered decomposition turns a headline ratio into operational causes. It also reduces the risk of false narratives. “Rates helped earnings” may be true at one layer while deposit competition, credit losses or securities duration offset the benefit elsewhere.

A good bank model therefore lets the analyst drill from ROE to underlying products and cash flows.

Balance-Sheet Optimisation Is Not Profit Maximisation Without Constraints

If only near-term NIM mattered, a bank might load the balance sheet with high-yield loans and fund them with the cheapest short-term liabilities. That would create credit concentration, liquidity mismatch, maturity transformation and potentially inadequate capital. Prudential constraints exist because a bank’s private earnings choices can create solvency and systemic risk.

Mathematically, the bank is solving a constrained optimisation problem: maximise a risk-adjusted objective subject to capital, liquidity, concentration, funding, rate-risk, credit-risk and operational limits. Shadow prices on those constraints explain why scarce balance-sheet capacity should be allocated to products that compensate for what they consume.

The existing specialist article How Banks Optimise the Balance Sheet owns the deeper optimisation mechanics.

A Professional Bank-Balance-Sheet Workflow

1. Reconcile the accounting identity at every reporting date.
2. Separate earning and non-earning assets.
3. Separate interest-bearing and non-interest-bearing funding.
4. Calculate average balances for flow-to-stock ratios.
5. Decompose NII into asset-yield, funding-cost, volume and mix effects.
6. Calculate NIM, ROAA and ROE on consistent denominators.
7. Separate operating cost and fee-income contributions.
8. Separate expected credit cost/provisions from core margin.
9. Map repricing and maturity buckets for assets and liabilities.
10. Measure liquidity and capital consumption alongside profitability.
11. Run funding, rate, credit and growth scenarios.
12. Reconcile every projected balance-sheet change to a funding/equity counterpart.

Common Failure Modes

1. Deposits on the wrong side

Deposits are liabilities from the bank’s perspective. The repair is to return to the accounting identity, ratio definition and time horizon before interpreting the result.

2. NIM and spread treated as identical

NIM uses net interest income over earning assets; a simple asset-yield minus funding-cost spread uses different denominators. The repair is to return to the accounting identity, ratio definition and time horizon before interpreting the result.

3. NII and NIM treated as identical

One is currency, the other is a normalised percentage. The repair is to return to the accounting identity, ratio definition and time horizon before interpreting the result.

4. Year-end denominator with full-year flow

Fast growth can distort ROA and yield ratios. The repair is to return to the accounting identity, ratio definition and time horizon before interpreting the result.

5. ROE read without leverage

Thin equity can mechanically boost ROE. The repair is to return to the accounting identity, ratio definition and time horizon before interpreting the result.

6. High loan yield called high profitability

Expected losses, capital and operating costs may consume the spread. The repair is to return to the accounting identity, ratio definition and time horizon before interpreting the result.

7. Average deposit cost used for new lending

Marginal funding cost can be much higher than book-average cost. The repair is to return to the accounting identity, ratio definition and time horizon before interpreting the result.

8. Contractual maturity used as behavioural maturity

Deposits and options can behave differently from legal dates. The repair is to return to the accounting identity, ratio definition and time horizon before interpreting the result.

9. Gap analysis used as full IRRBB

Basis, option and curve-shape risk remain. The repair is to return to the accounting identity, ratio definition and time horizon before interpreting the result.

10. Profit maximisation without liquidity/capital constraints

The mathematically highest yield can be prudentially infeasible. The repair is to return to the accounting identity, ratio definition and time horizon before interpreting the result.

11. No balance-sheet reconciliation

Projected assets must have a liability/equity funding source. The repair is to return to the accounting identity, ratio definition and time horizon before interpreting the result.

12. Accounting value treated as market value

Economic sensitivity can exist even when book carrying value does not move one-for-one. The repair is to return to the accounting identity, ratio definition and time horizon before interpreting the result.

Formula Map

Measure	Simplified formula	Meaning
Balance sheet	A=L+E	Accounting identity.
Net interest income	NII=Interest income−Interest expense	Currency interest earnings.
NIM	NII/Average earning assets	Interest margin on earning assets.
Asset yield	Interest income/Average earning assets	Gross earning-asset yield.
Funding cost	Interest expense/Average interest-bearing liabilities	Explicit average funding cost.
ROAA	Net income/Average assets	Profit per unit of assets.
ROE	Net income/Average equity	Profit per unit of equity.
Equity multiplier	Average assets/Average equity	Simple accounting leverage.
Loan-to-deposit	Loans/Deposits	Simple funding-structure ratio.

Authoritative Reference Map

• Federal Reserve — June 2026 Supervision and Regulation Report: Banking System Conditions
• Federal Reserve — Assessing Bank Resilience to a Funding Shock (2026)
• FDIC — Net Interest Margins and Interest Rates
• Basel Framework — Overview of Risk Management, Prudential Metrics and RWA Disclosures

Connected Banking And Finance Mathematics Route

• Banking And Finance Mathematics | Complete Mathematical System
• Credit Risk, PD, LGD, EAD and Expected Loss
• Duration, Convexity, DV01 and Interest-Rate Risk
• How Banks Optimise the Balance Sheet
• How Banks Measure Interest-Rate Risk
• Finance & Banking Algorithms

Applied Case Study 1: A deposit-funded mortgage bank

Situation. The bank holds long fixed-rate mortgages funded by savings deposits. The objective is to connect profitability to the balance-sheet structure producing it.

Method. Map contractual and behavioural cash flows, calculate NIM, deposit beta and duration gap, then run rate-rise and rate-fall scenarios. Adrian checks the accounting identity, Jo separates average and marginal rates, Aisha maps repricing and credit assumptions, and Ryan reconciles the projected NII to product-level cash flows.

Boundary. Near-term NIM can improve while economic value declines if fixed-rate assets lose value. Mira then asks what capital, liquidity or customer behaviour constraint prevents the apparently highest-margin strategy from being universally optimal.

Applied Case Study 2: A credit-card bank

Situation. High-yield revolving assets produce high gross asset yield but also high credit-loss and funding costs. The objective is to connect profitability to the balance-sheet structure producing it.

Method. Decompose asset yield, funding cost, expected loss, operating cost and capital charge rather than reading NIM alone. Adrian checks the accounting identity, Jo separates average and marginal rates, Aisha maps repricing and credit assumptions, and Ryan reconciles the projected NII to product-level cash flows.

Boundary. A high NIM is not automatically a high risk-adjusted return. Mira then asks what capital, liquidity or customer behaviour constraint prevents the apparently highest-margin strategy from being universally optimal.

Applied Case Study 3: A transaction bank

Situation. Large non-interest-bearing operating deposits support a balance sheet with lower-yield assets and high fee income. The objective is to connect profitability to the balance-sheet structure producing it.

Method. Separate NIM economics from payments/fee economics and value deposit stability. Adrian checks the accounting identity, Jo separates average and marginal rates, Aisha maps repricing and credit assumptions, and Ryan reconciles the projected NII to product-level cash flows.

Boundary. Comparing its NIM directly with a credit-card bank without business-model context is weak analysis. Mira then asks what capital, liquidity or customer behaviour constraint prevents the apparently highest-margin strategy from being universally optimal.

Applied Case Study 4: A wholesale-funded bank

Situation. The bank relies heavily on market funding instead of retail deposits. The objective is to connect profitability to the balance-sheet structure producing it.

Method. Shock wholesale spreads and rollover assumptions, then recompute NII and liquidity. Adrian checks the accounting identity, Jo separates average and marginal rates, Aisha maps repricing and credit assumptions, and Ryan reconciles the projected NII to product-level cash flows.

Boundary. Average funding cost can jump quickly when markets reprice. Mira then asks what capital, liquidity or customer behaviour constraint prevents the apparently highest-margin strategy from being universally optimal.

Applied Case Study 5: A fast-growing SME lender

Situation. Loans grow 25% while equity grows only 5%. The objective is to connect profitability to the balance-sheet structure producing it.

Method. Project funding, RWA, provisions and capital ratios alongside NII. Adrian checks the accounting identity, Jo separates average and marginal rates, Aisha maps repricing and credit assumptions, and Ryan reconciles the projected NII to product-level cash flows.

Boundary. Growth can increase profit and simultaneously reduce capital headroom. Mira then asks what capital, liquidity or customer behaviour constraint prevents the apparently highest-margin strategy from being universally optimal.

Applied Case Study 6: A securities-heavy bank

Situation. A large fixed-rate securities portfolio creates duration exposure. The objective is to connect profitability to the balance-sheet structure producing it.

Method. Calculate market-value sensitivity, accounting treatment, NIM carry and liquidity role separately. Adrian checks the accounting identity, Jo separates average and marginal rates, Aisha maps repricing and credit assumptions, and Ryan reconciles the projected NII to product-level cash flows.

Boundary. Low credit risk does not mean low interest-rate risk. Mira then asks what capital, liquidity or customer behaviour constraint prevents the apparently highest-margin strategy from being universally optimal.

Applied Case Study 7: A bank facing deposit competition

Situation. Competitors raise savings rates aggressively after benchmark rates rise. The objective is to connect profitability to the balance-sheet structure producing it.

Method. Increase deposit beta and migration into term deposits, then project NIM. Adrian checks the accounting identity, Jo separates average and marginal rates, Aisha maps repricing and credit assumptions, and Ryan reconciles the projected NII to product-level cash flows.

Boundary. Deposit mix and customer behaviour can dominate headline policy-rate effects. Mira then asks what capital, liquidity or customer behaviour constraint prevents the apparently highest-margin strategy from being universally optimal.

Applied Case Study 8: A funding run scenario

Situation. Deposits leave quickly and are replaced with expensive secured or wholesale funding. The objective is to connect profitability to the balance-sheet structure producing it.

Method. Model runoff, HQLA use, asset sales, replacement cost and NIM compression. Adrian checks the accounting identity, Jo separates average and marginal rates, Aisha maps repricing and credit assumptions, and Ryan reconciles the projected NII to product-level cash flows.

Boundary. Profitability and liquidity become linked under stress. Mira then asks what capital, liquidity or customer behaviour constraint prevents the apparently highest-margin strategy from being universally optimal.

Applied Case Study 9: A provision cycle

Situation. Credit conditions worsen after a period of strong loan growth. The objective is to connect profitability to the balance-sheet structure producing it.

Method. Hold NIM initially stable but raise expected credit losses and charge-offs. Adrian checks the accounting identity, Jo separates average and marginal rates, Aisha maps repricing and credit assumptions, and Ryan reconciles the projected NII to product-level cash flows.

Boundary. Core margin can look healthy while net income and capital weaken. Mira then asks what capital, liquidity or customer behaviour constraint prevents the apparently highest-margin strategy from being universally optimal.

Applied Case Study 10: A fixed-to-floating asset shift

Situation. The bank originates more floating-rate corporate loans and fewer fixed-rate mortgages. The objective is to connect profitability to the balance-sheet structure producing it.

Method. Compare asset beta, NII sensitivity, credit sensitivity and customer behaviour. Adrian checks the accounting identity, Jo separates average and marginal rates, Aisha maps repricing and credit assumptions, and Ryan reconciles the projected NII to product-level cash flows.

Boundary. Faster asset repricing may improve rate protection but transfer stress to borrowers. Mira then asks what capital, liquidity or customer behaviour constraint prevents the apparently highest-margin strategy from being universally optimal.

Applied Case Study 11: A branch-heavy retail bank

Situation. Operating costs are high but deposits are stable and cheap. The objective is to connect profitability to the balance-sheet structure producing it.

Method. Evaluate efficiency ratio together with funding value and fee/customer economics. Adrian checks the accounting identity, Jo separates average and marginal rates, Aisha maps repricing and credit assumptions, and Ryan reconciles the projected NII to product-level cash flows.

Boundary. A cost-only optimisation may destroy franchise funding advantages. Mira then asks what capital, liquidity or customer behaviour constraint prevents the apparently highest-margin strategy from being universally optimal.

Applied Case Study 12: A digital challenger bank

Situation. Rapid deposit growth is attracted by high promotional rates. The objective is to connect profitability to the balance-sheet structure producing it.

Method. Separate headline deposit growth from marginal funding cost, retention and stability. Adrian checks the accounting identity, Jo separates average and marginal rates, Aisha maps repricing and credit assumptions, and Ryan reconciles the projected NII to product-level cash flows.

Boundary. Fast growth can be expensive and rate-sensitive rather than durable. Mira then asks what capital, liquidity or customer behaviour constraint prevents the apparently highest-margin strategy from being universally optimal.

Final Principle

A bank balance sheet is not a static table. It is a network of dated assets and funding claims whose rates, losses, liquidity and capital requirements interact through time.

The accounting identity keeps the system numerically closed. NIM explains interest economics. ROAA explains asset productivity. ROE adds leverage. Provisions introduce expected credit cost. Capital and liquidity determine whether the balance sheet can survive the risks required to earn those returns.

The strongest bank analysis therefore decomposes rather than labels. Instead of saying “profit improved,” ask whether asset yield, deposit beta, funding mix, credit cost, fee income, operating efficiency or leverage changed. Instead of saying “growth is good,” ask what funded it and what scarce balance-sheet resources it consumed.

That prepares the next two owners naturally: bank capital mathematics and bank liquidity mathematics.

Deep Practice Lab 1: Rebuild NIM from the balance sheet

Create a simple bank with three earning-asset classes and three funding classes. Calculate each class’s average balance and rate, total interest income, total interest expense, NII and NIM. Then change one rate at a time and attribute the NIM movement.

Complete the lab with a full reconciliation: assets must equal liabilities plus equity before and after every scenario. Ben should identify the cash-flow source of each income line; Clara should label the denominator convention for every ratio; Ethan should specify one stress that would reverse the apparent profitability advantage.

Finish by separating accounting result from economic interpretation. A ratio can improve because of genuine product economics, leverage, balance-sheet mix, one-off gains or denominator changes. Write which mechanism explains the movement rather than allowing the ratio to speak for itself.

Deep Practice Lab 2: Separate average and marginal funding cost

Calculate average deposit cost from an existing book, then calculate the cost of attracting S$100m of new deposits today. Price a new loan using each cost and compare the apparent margin. Explain which measure is more relevant to incremental growth.

Complete the lab with a full reconciliation: assets must equal liabilities plus equity before and after every scenario. Ben should identify the cash-flow source of each income line; Clara should label the denominator convention for every ratio; Ethan should specify one stress that would reverse the apparent profitability advantage.

Finish by separating accounting result from economic interpretation. A ratio can improve because of genuine product economics, leverage, balance-sheet mix, one-off gains or denominator changes. Write which mechanism explains the movement rather than allowing the ratio to speak for itself.

Deep Practice Lab 3: Decompose ROE

Start with net income, average assets and average equity. Compute ROAA, equity multiplier and ROE. Then halve equity while holding everything else fixed. Identify the mechanical increase in ROE and the associated loss-absorption reduction.

Complete the lab with a full reconciliation: assets must equal liabilities plus equity before and after every scenario. Ben should identify the cash-flow source of each income line; Clara should label the denominator convention for every ratio; Ethan should specify one stress that would reverse the apparent profitability advantage.

Finish by separating accounting result from economic interpretation. A ratio can improve because of genuine product economics, leverage, balance-sheet mix, one-off gains or denominator changes. Write which mechanism explains the movement rather than allowing the ratio to speak for itself.

Deep Practice Lab 4: Run a deposit-beta scenario

Shock a benchmark rate by +200bp. Apply several deposit betas to different product groups and different asset betas to loans/securities. Calculate NII under each scenario. Identify which product mix creates the largest margin sensitivity.

Complete the lab with a full reconciliation: assets must equal liabilities plus equity before and after every scenario. Ben should identify the cash-flow source of each income line; Clara should label the denominator convention for every ratio; Ethan should specify one stress that would reverse the apparent profitability advantage.

Finish by separating accounting result from economic interpretation. A ratio can improve because of genuine product economics, leverage, balance-sheet mix, one-off gains or denominator changes. Write which mechanism explains the movement rather than allowing the ratio to speak for itself.

Deep Practice Lab 5: Balance growth with capital and liquidity

Add S$500m of loans to a model bank. Fund them with deposits, wholesale debt or equity in separate scenarios. Compare NIM, accounting leverage, funding concentration and the direction of capital/liquidity ratios.

Complete the lab with a full reconciliation: assets must equal liabilities plus equity before and after every scenario. Ben should identify the cash-flow source of each income line; Clara should label the denominator convention for every ratio; Ethan should specify one stress that would reverse the apparent profitability advantage.

Finish by separating accounting result from economic interpretation. A ratio can improve because of genuine product economics, leverage, balance-sheet mix, one-off gains or denominator changes. Write which mechanism explains the movement rather than allowing the ratio to speak for itself.

Deep Practice Lab 6: Rebuild NIM from the balance sheet

Create a simple bank with three earning-asset classes and three funding classes. Calculate each class’s average balance and rate, total interest income, total interest expense, NII and NIM. Then change one rate at a time and attribute the NIM movement.

Complete the lab with a full reconciliation: assets must equal liabilities plus equity before and after every scenario. Ben should identify the cash-flow source of each income line; Clara should label the denominator convention for every ratio; Ethan should specify one stress that would reverse the apparent profitability advantage.

Finish by separating accounting result from economic interpretation. A ratio can improve because of genuine product economics, leverage, balance-sheet mix, one-off gains or denominator changes. Write which mechanism explains the movement rather than allowing the ratio to speak for itself.

Deep Practice Lab 7: Separate average and marginal funding cost

Calculate average deposit cost from an existing book, then calculate the cost of attracting S$100m of new deposits today. Price a new loan using each cost and compare the apparent margin. Explain which measure is more relevant to incremental growth.

Complete the lab with a full reconciliation: assets must equal liabilities plus equity before and after every scenario. Ben should identify the cash-flow source of each income line; Clara should label the denominator convention for every ratio; Ethan should specify one stress that would reverse the apparent profitability advantage.

Finish by separating accounting result from economic interpretation. A ratio can improve because of genuine product economics, leverage, balance-sheet mix, one-off gains or denominator changes. Write which mechanism explains the movement rather than allowing the ratio to speak for itself.

Deep Practice Lab 8: Decompose ROE

Start with net income, average assets and average equity. Compute ROAA, equity multiplier and ROE. Then halve equity while holding everything else fixed. Identify the mechanical increase in ROE and the associated loss-absorption reduction.

Complete the lab with a full reconciliation: assets must equal liabilities plus equity before and after every scenario. Ben should identify the cash-flow source of each income line; Clara should label the denominator convention for every ratio; Ethan should specify one stress that would reverse the apparent profitability advantage.

Finish by separating accounting result from economic interpretation. A ratio can improve because of genuine product economics, leverage, balance-sheet mix, one-off gains or denominator changes. Write which mechanism explains the movement rather than allowing the ratio to speak for itself.

Deep Practice Lab 9: Run a deposit-beta scenario

Shock a benchmark rate by +200bp. Apply several deposit betas to different product groups and different asset betas to loans/securities. Calculate NII under each scenario. Identify which product mix creates the largest margin sensitivity.

Complete the lab with a full reconciliation: assets must equal liabilities plus equity before and after every scenario. Ben should identify the cash-flow source of each income line; Clara should label the denominator convention for every ratio; Ethan should specify one stress that would reverse the apparent profitability advantage.

Finish by separating accounting result from economic interpretation. A ratio can improve because of genuine product economics, leverage, balance-sheet mix, one-off gains or denominator changes. Write which mechanism explains the movement rather than allowing the ratio to speak for itself.

Deep Practice Lab 10: Balance growth with capital and liquidity

Add S$500m of loans to a model bank. Fund them with deposits, wholesale debt or equity in separate scenarios. Compare NIM, accounting leverage, funding concentration and the direction of capital/liquidity ratios.

Complete the lab with a full reconciliation: assets must equal liabilities plus equity before and after every scenario. Ben should identify the cash-flow source of each income line; Clara should label the denominator convention for every ratio; Ethan should specify one stress that would reverse the apparent profitability advantage.

Finish by separating accounting result from economic interpretation. A ratio can improve because of genuine product economics, leverage, balance-sheet mix, one-off gains or denominator changes. Write which mechanism explains the movement rather than allowing the ratio to speak for itself.

Deep Practice Lab 11: Rebuild NIM from the balance sheet

Create a simple bank with three earning-asset classes and three funding classes. Calculate each class’s average balance and rate, total interest income, total interest expense, NII and NIM. Then change one rate at a time and attribute the NIM movement.

Complete the lab with a full reconciliation: assets must equal liabilities plus equity before and after every scenario. Ben should identify the cash-flow source of each income line; Clara should label the denominator convention for every ratio; Ethan should specify one stress that would reverse the apparent profitability advantage.

Finish by separating accounting result from economic interpretation. A ratio can improve because of genuine product economics, leverage, balance-sheet mix, one-off gains or denominator changes. Write which mechanism explains the movement rather than allowing the ratio to speak for itself.

Deep Practice Lab 12: Separate average and marginal funding cost

Calculate average deposit cost from an existing book, then calculate the cost of attracting S$100m of new deposits today. Price a new loan using each cost and compare the apparent margin. Explain which measure is more relevant to incremental growth.

Complete the lab with a full reconciliation: assets must equal liabilities plus equity before and after every scenario. Ben should identify the cash-flow source of each income line; Clara should label the denominator convention for every ratio; Ethan should specify one stress that would reverse the apparent profitability advantage.

Finish by separating accounting result from economic interpretation. A ratio can improve because of genuine product economics, leverage, balance-sheet mix, one-off gains or denominator changes. Write which mechanism explains the movement rather than allowing the ratio to speak for itself.

Deep Practice Lab 13: Decompose ROE

Start with net income, average assets and average equity. Compute ROAA, equity multiplier and ROE. Then halve equity while holding everything else fixed. Identify the mechanical increase in ROE and the associated loss-absorption reduction.

Complete the lab with a full reconciliation: assets must equal liabilities plus equity before and after every scenario. Ben should identify the cash-flow source of each income line; Clara should label the denominator convention for every ratio; Ethan should specify one stress that would reverse the apparent profitability advantage.

Finish by separating accounting result from economic interpretation. A ratio can improve because of genuine product economics, leverage, balance-sheet mix, one-off gains or denominator changes. Write which mechanism explains the movement rather than allowing the ratio to speak for itself.

Deep Practice Lab 14: Run a deposit-beta scenario

Shock a benchmark rate by +200bp. Apply several deposit betas to different product groups and different asset betas to loans/securities. Calculate NII under each scenario. Identify which product mix creates the largest margin sensitivity.

Complete the lab with a full reconciliation: assets must equal liabilities plus equity before and after every scenario. Ben should identify the cash-flow source of each income line; Clara should label the denominator convention for every ratio; Ethan should specify one stress that would reverse the apparent profitability advantage.

Finish by separating accounting result from economic interpretation. A ratio can improve because of genuine product economics, leverage, balance-sheet mix, one-off gains or denominator changes. Write which mechanism explains the movement rather than allowing the ratio to speak for itself.

Deep Practice Lab 15: Balance growth with capital and liquidity

Add S$500m of loans to a model bank. Fund them with deposits, wholesale debt or equity in separate scenarios. Compare NIM, accounting leverage, funding concentration and the direction of capital/liquidity ratios.

Complete the lab with a full reconciliation: assets must equal liabilities plus equity before and after every scenario. Ben should identify the cash-flow source of each income line; Clara should label the denominator convention for every ratio; Ethan should specify one stress that would reverse the apparent profitability advantage.

Finish by separating accounting result from economic interpretation. A ratio can improve because of genuine product economics, leverage, balance-sheet mix, one-off gains or denominator changes. Write which mechanism explains the movement rather than allowing the ratio to speak for itself.

Deep Practice Lab 16: Rebuild NIM from the balance sheet

Create a simple bank with three earning-asset classes and three funding classes. Calculate each class’s average balance and rate, total interest income, total interest expense, NII and NIM. Then change one rate at a time and attribute the NIM movement.

Complete the lab with a full reconciliation: assets must equal liabilities plus equity before and after every scenario. Ben should identify the cash-flow source of each income line; Clara should label the denominator convention for every ratio; Ethan should specify one stress that would reverse the apparent profitability advantage.

Finish by separating accounting result from economic interpretation. A ratio can improve because of genuine product economics, leverage, balance-sheet mix, one-off gains or denominator changes. Write which mechanism explains the movement rather than allowing the ratio to speak for itself.

Deep Practice Lab 17: Separate average and marginal funding cost

Calculate average deposit cost from an existing book, then calculate the cost of attracting S$100m of new deposits today. Price a new loan using each cost and compare the apparent margin. Explain which measure is more relevant to incremental growth.

Complete the lab with a full reconciliation: assets must equal liabilities plus equity before and after every scenario. Ben should identify the cash-flow source of each income line; Clara should label the denominator convention for every ratio; Ethan should specify one stress that would reverse the apparent profitability advantage.

Finish by separating accounting result from economic interpretation. A ratio can improve because of genuine product economics, leverage, balance-sheet mix, one-off gains or denominator changes. Write which mechanism explains the movement rather than allowing the ratio to speak for itself.

Deep Practice Lab 18: Decompose ROE

Start with net income, average assets and average equity. Compute ROAA, equity multiplier and ROE. Then halve equity while holding everything else fixed. Identify the mechanical increase in ROE and the associated loss-absorption reduction.

Complete the lab with a full reconciliation: assets must equal liabilities plus equity before and after every scenario. Ben should identify the cash-flow source of each income line; Clara should label the denominator convention for every ratio; Ethan should specify one stress that would reverse the apparent profitability advantage.

Finish by separating accounting result from economic interpretation. A ratio can improve because of genuine product economics, leverage, balance-sheet mix, one-off gains or denominator changes. Write which mechanism explains the movement rather than allowing the ratio to speak for itself.

Deep Practice Lab 19: Run a deposit-beta scenario

Shock a benchmark rate by +200bp. Apply several deposit betas to different product groups and different asset betas to loans/securities. Calculate NII under each scenario. Identify which product mix creates the largest margin sensitivity.

Complete the lab with a full reconciliation: assets must equal liabilities plus equity before and after every scenario. Ben should identify the cash-flow source of each income line; Clara should label the denominator convention for every ratio; Ethan should specify one stress that would reverse the apparent profitability advantage.

Finish by separating accounting result from economic interpretation. A ratio can improve because of genuine product economics, leverage, balance-sheet mix, one-off gains or denominator changes. Write which mechanism explains the movement rather than allowing the ratio to speak for itself.

Deep Practice Lab 20: Balance growth with capital and liquidity

Add S$500m of loans to a model bank. Fund them with deposits, wholesale debt or equity in separate scenarios. Compare NIM, accounting leverage, funding concentration and the direction of capital/liquidity ratios.

Complete the lab with a full reconciliation: assets must equal liabilities plus equity before and after every scenario. Ben should identify the cash-flow source of each income line; Clara should label the denominator convention for every ratio; Ethan should specify one stress that would reverse the apparent profitability advantage.

Finish by separating accounting result from economic interpretation. A ratio can improve because of genuine product economics, leverage, balance-sheet mix, one-off gains or denominator changes. Write which mechanism explains the movement rather than allowing the ratio to speak for itself.

Deep Practice Lab 21: Rebuild NIM from the balance sheet

Create a simple bank with three earning-asset classes and three funding classes. Calculate each class’s average balance and rate, total interest income, total interest expense, NII and NIM. Then change one rate at a time and attribute the NIM movement.

Complete the lab with a full reconciliation: assets must equal liabilities plus equity before and after every scenario. Ben should identify the cash-flow source of each income line; Clara should label the denominator convention for every ratio; Ethan should specify one stress that would reverse the apparent profitability advantage.

Finish by separating accounting result from economic interpretation. A ratio can improve because of genuine product economics, leverage, balance-sheet mix, one-off gains or denominator changes. Write which mechanism explains the movement rather than allowing the ratio to speak for itself.