FRM Part II · FRM Exam Part II
Liquidity Stress Testing: formula sheet
Key formulas
- Net cash flow in a period
- Net cash flow = Cash inflows − Cash outflows
- Stressed inflows are reduced and outflows are increased by scenario assumptions.
- Cumulative liquidity position
- Cumulative gap(t) = Liquidity buffer (after haircuts) + Σ net cash flows up to t
- The first t where it turns negative is the survival horizon.
- Buffer value after haircut
- Haircut value = Market value × (1 − haircut)
- Use the stressed haircut, not the normal one.
- Survival horizon
- Survival horizon = number of days until the cumulative liquidity position falls below zero
- Compare it with the horizon set by policy or regulation.
- Survival horizon
- Survival horizon = the first day on which cumulative net cash flow plus starting buffer falls below zero
- Compare it with the minimum the bank's risk appetite requires.
- Net stressed cash flow
- Net stressed outflow = Stressed outflows − Stressed inflows
- Apply run-off rates to liabilities and haircuts or delayed receipt to assets.
- Liquidity buffer after stress
- Buffer after stress = Σ (market value of asset × (1 − stressed haircut))
- Include only assets that are unencumbered and can truly be monetised in that scenario.
- Stressed run-off outflow
- Outflow = Balance × run-off rate
- Rates are higher for unsecured wholesale and uninsured funding than for stable retail deposits.
- Scenario severity ordering
- Idiosyncratic < Market-wide < Combined (typical severity for a given bank)
- A rule of thumb, not a law. Market-wide can be milder for a bank with little exposure to it.
- Stressed outflow from deposits
- Outflow = Balance × run-off rate
- Use a different rate for each deposit category, then sum.
- Credit line drawdown
- Drawdown = Undrawn committed amount × drawdown rate
- Apply to the undrawn part only. Drawn balances are already on the balance sheet.
- Rollover shortfall
- Outflow = Maturing funding × (1 − rollover rate)
- Only the part not renewed is a net cash outflow.
- Stressed inflow
- Inflow = Contractual inflow × (1 − haircut)
- Inflows are reduced because not all will be received in stress.
- Net cash flow
- Net = Stressed inflows − Stressed outflows (including collateral calls)
- A negative number is a funding need.
- Cumulative gap and survival
- Cumulative net flow + Buffer ≥ 0 at each bucket
- Survival horizon is the last bucket where this holds.
- Haircut-adjusted liquidity value
- Liquidity value = Market value × (1 − haircut)
- Apply to each asset class separately. Cash has a haircut of 0%.
- Counterbalancing capacity
- CBC = Σ [Market value_i × (1 − haircut_i)] over unencumbered assets monetizable within the time bucket
- Exclude encumbered assets. Include only assets that can be monetized within the bucket.
- Stressed net cash outflow
- Net outflow_t = Stressed outflows_t − Stressed inflows_t
- Inflows are often capped or haircut. Use the supervisor's or the scenario's rates.
- Cumulative liquidity position
- Position_t = CBC available by t − Σ Net outflows up to t
- The first t with Position_t < 0 marks the end of the survival horizon.
- Approximate survival horizon (constant outflow)
- Survival days ≈ CBC ÷ daily stressed net outflow
- Valid only if outflows are roughly even. Use the day-by-day method if they are not.
- Liquidity Coverage Ratio
- LCR = Stock of HQLA ÷ Total net cash outflows over next 30 calendar days ≥ 100%
- Short-term, stress-based. HQLA is measured after haircuts and caps.
- Total net cash outflows
- Net outflows = Total expected outflows − MIN(total expected inflows, 75% of total expected outflows)
- Inflows are capped at 75% of outflows, so net outflows are never below 25% of gross outflows.
- Net Stable Funding Ratio
- NSFR = Available stable funding (ASF) ÷ Required stable funding (RSF) ≥ 100%
- Structural, covers a one-year horizon. Each item is weighted by an ASF or RSF factor.
- ASF and RSF weighting
- ASF = Σ (liability or capital amount × ASF factor); RSF = Σ (asset or off-balance-sheet amount × RSF factor)
- Regulatory capital and liabilities of one year or more get a 100% ASF factor. Cash and central bank reserves get a 0% RSF factor in Basel's standard.
- Outflow amount
- Outflow = Balance × run-off rate
- Stable retail deposits have a lower run-off rate than unsecured wholesale funding from financial institutions.
- HQLA after haircut
- Eligible HQLA = Market value × (1 − haircut)
- Level 1 has no haircut. Level 2A has a 15% haircut. Level 2B has haircuts of 25% or 50% depending on asset type.
- Survival horizon
- Survival horizon = the first day on which cumulative net outflows > liquidity buffer
- Compare cumulative net stressed outflows with available buffer after haircuts. Report the number of days.
- Liquidity surplus or shortfall
- Surplus (shortfall) = Buffer after haircuts − Cumulative stressed net outflows
- A negative result means the CFP must supply the gap.
- Buffer after haircuts
- Buffer value = Σ (market value × (1 − haircut))
- Apply haircuts to each asset class before comparing with outflows.
- Reverse stress test logic
- Define failure → find scenario that causes it → judge plausibility → act
- The starting point is the outcome, not the scenario.
- Limit utilisation
- Utilisation = Measured exposure ÷ Limit
- Above 100% is a breach and triggers escalation.
Quick revision
- Funding liquidity risk is the inability to meet obligations when due; market liquidity risk is the inability to sell assets without a large price impact.
- A stress test needs a scenario, cash flow projections, assumptions, a buffer and a horizon.
- Combined scenarios mix a firm-specific shock with a market-wide shock and are usually the most severe.
- Deposit run-off depends on type: insured retail deposits run off less than uninsured or wholesale deposits.
- Committed credit and liquidity lines create contingent outflows through drawdowns.
- Counterbalancing capacity is the stock of assets that can be sold, repo'd or pledged to raise cash. Apply haircuts to it.
- Survival horizon is how long the bank can meet net outflows before the buffer is exhausted.
- LCR = stock of high-quality liquid assets ÷ total net cash outflows over 30 days, and it must be at least 100%.
- NSFR = available stable funding ÷ required stable funding, and it must be at least 100%. It addresses a one-year structural horizon.
- Net outflows in the LCR equal outflows minus the lesser of inflows and 75% of outflows.
- Reverse stress testing starts from a failure outcome and works back to the scenarios that cause it.
- Results should feed limits, the contingency funding plan and strategic decisions, with senior management and board oversight.
Common mistakes
- Treating market and funding liquidity as the same thing Fix: Ask whether the problem is selling an asset (market) or obtaining cash (funding). Remember they interact through spirals.
- Saying a liquidity stress test measures capital adequacy Fix: Liquidity tests look at cash flows and survival horizon. Capital tests look at losses and capital ratios.
- Assuming assets can be sold at normal prices in a market-wide scenario. Fix: In market-wide and combined scenarios, apply higher haircuts and limit sales to the truly liquid assets.
- Calling a combined scenario simply the sum of two mild shocks. Fix: A combined scenario is a bank-specific shock occurring during market stress, with interactions such as loss of access to wholesale funding when the bank cannot sell assets.
- Applying the drawdown rate to the whole commitment instead of the undrawn part. Fix: Subtract drawn amounts first. Drawdown = undrawn × rate.
- Using the rollover rate as the outflow rate. Fix: Outflow = maturing amount × (1 − rollover rate). A 70% rollover means 30% leaves.
- Using market value instead of haircut value Fix: Always multiply by (1 − haircut) before adding assets. Do it first, every time.
- Counting encumbered assets in the buffer Fix: Read the question for pledged, repo'd or collateral-posted assets and exclude them.
- Mixing up horizons: calling the NSFR a 30-day measure. Fix: Remember: LCR = liquidity in a 30-day storm; NSFR = funding structure over a year.
- Forgetting the 75% cap on inflows in the LCR denominator. Fix: Net outflows = outflows − MIN(inflows, 0.75 × outflows). Always compute the cap.
Exam tips
- Expect scenario questions that ask you to label the risk as market or funding liquidity. Look for the trigger words.
- Know the interaction: funding stress forces asset sales, which hit market prices and raise haircuts and margin calls.
- For differences between tests, remember: cash and short horizon for liquidity, losses and capital ratios for solvency.
- In numerical items, apply haircuts before adding flows and use stressed assumptions.
- Be ready to name uses of results: buffer sizing, limits, early warning indicators and contingency funding plan testing.
- Read the case for the funding model first. The right scenario usually follows from it.
- If markets are described as frozen, assume asset sales are limited and haircuts are higher.
- Check whether an option confuses LCR's 30-day stress with a required horizon for all stress tests.