FRM Part II · FRM Exam Part II
Credit Value Adjustment: formula sheet
Key formulas
- Exposure at date t
- E(t) = max(V(t), 0)
- V is the portfolio value to you. For a netting set, net the trades first, then take the max.
- Expected exposure
- EE(t) = E[max(V(t), 0)]
- Includes the zero outcomes. It is always at least max(E[V(t)], 0).
- Potential future exposure
- PFE(t) = the α-percentile of E(t), i.e. P(E(t) ≤ PFE) = α
- Common α is 95% or 97.5%. Peak PFE is the maximum over time.
- Expected positive exposure
- EPE = (1 ÷ T) × ∫ EE(t) dt ≈ Σ EE(tᵢ) × Δtᵢ ÷ T
- A time-weighted average of EE. Use time weights if the dates are unevenly spaced.
- Effective EE
- Effective EE(tₖ) = max(Effective EE(tₖ₋₁), EE(tₖ))
- Running maximum, so the profile is non-decreasing.
- Effective EPE
- Effective EPE = Σ Effective EE(tₖ) × Δtₖ ÷ T, over the first year
- Basel horizon is the shorter of one year and the longest maturity in the netting set.
- Normal exposure percentile
- If V ~ N(μ, σ²) and PFE > 0: PFE = μ + z × σ
- z = 1.645 for 95% and 1.96 for 97.5%. Floor at zero.
- Regulatory EAD (internal model method)
- EAD = α × Effective EPE, with α = 1.4 unless supervisors approve otherwise
- α is a multiplier calibrated by Basel. State it as the default.
- Exposure without netting
- Exposure = Σ max(Vi, 0)
- Sum over each trade i. Only positive-value trades count. Used when netting is not enforceable.
- Exposure with close-out netting
- Exposure = max(Σ Vi, 0)
- Sum over trades in one legally enforceable netting set. Always ≤ the no-netting exposure.
- Netting benefit
- Benefit = Σ max(Vi, 0) − max(Σ Vi, 0)
- Zero if all trades have the same sign. Largest when trades offset.
- Net-to-gross ratio (NGR)
- NGR = max(Σ Vi, 0) ÷ Σ max(Vi, 0)
- Between 0 and 1. Lower means more netting benefit.
- Exposure with collateral
- Exposure = max(V − C, 0)
- V is net value at close-out, C is collateral held after haircuts.
- Collateral call with threshold and MTA
- Call = max(V − Threshold − Collateral held, 0), made only if the amount ≥ MTA
- If the calculated amount is below the MTA, no transfer happens. Practical CSAs also apply rounding.
- Maximum uncollateralised gap (simple view)
- Residual exposure ≈ Threshold + MTA + change in V over MPOR
- A rule of thumb for the worst case just before default. Initial margin or independent amount reduces it.
- Volatility over the MPOR
- σ(MPOR) = σ(1 day) × √(MPOR in days)
- Square-root-of-time scaling under independent, identically distributed changes. Use only as an approximation.
- Haircut collateral value
- Collateral value = Market value × (1 − haircut)
- Haircut reflects the price volatility and liquidity of non-cash collateral.
- Unilateral CVA (discrete)
- CVA = LGD × Σ [ EE*(tᵢ) × PD(tᵢ₋₁, tᵢ) ]
- EE* is discounted expected exposure, EE(tᵢ) × DF(tᵢ). Assumes exposure is independent of default.
- Loss given default
- LGD = 1 − R
- R is the recovery rate. Use the same R for all dates unless told otherwise.
- Marginal default probability
- PD(tᵢ₋₁, tᵢ) = Q(tᵢ₋₁) − Q(tᵢ)
- Q(t) is the survival probability to time t. Q(0) = 1.
- Survival probability from constant hazard
- Q(t) = e^(−λt)
- λ is the constant default intensity. Approximately λ ≈ credit spread ÷ LGD (credit triangle).
- Adjusted value
- Risky value = Risk-free value − CVA
- Unilateral CVA is a non-negative number that reduces the value of your claim on the counterparty.
- Single-period shortcut
- CVA ≈ PD × LGD × discounted EE
- Use only when the question gives one period or one average exposure.
- Bilateral value
- Value = Risk-free value − CVA + DVA
- CVA lowers value. DVA raises value. Bilateral CVA charge = CVA − DVA.
- Unilateral CVA (discrete)
- CVA = LGD_C × Σ EPE(tᵢ) × DF(tᵢ) × PD(tᵢ₋₁, tᵢ)
- EPE is the expected positive exposure. PD is the counterparty's marginal default probability in the period. LGD_C is the counterparty's loss given default.
- DVA (discrete)
- DVA = LGD_own × Σ ENE(tᵢ) × DF(tᵢ) × PD_own(tᵢ₋₁, tᵢ)
- ENE is the expected negative exposure, taken as a positive amount. Uses your own default probability and your own LGD.
- First-to-default adjustment
- CVA uses PD_C × survival of own; DVA uses PD_own × survival of counterparty
- Each default probability is multiplied by the other party's survival probability to that time. This avoids double counting.
- Credit triangle (approximation)
- Spread ≈ PD (annual hazard) × LGD
- Use it to turn a CDS spread into a default probability when the question gives spreads.
- Simple CVA (independence)
- CVA ≈ LGD × Σ EE(tᵢ) × PD(tᵢ₋₁, tᵢ) × DF(tᵢ)
- Uses discounted expected exposure EE and marginal default probability PD, with exposure and default assumed independent.
- Wrong-way effect
- Positive dependence ⇒ CVA with dependence > CVA under independence
- Exposure conditional on default exceeds unconditional expected exposure.
- Right-way effect
- Negative dependence ⇒ CVA with dependence < CVA under independence
- Exposure conditional on default is below unconditional expected exposure.
- Conditional exposure view
- CVA ≈ LGD × Σ E[Exposure | default at tᵢ] × PD(tᵢ) × DF(tᵢ)
- Replace EE by exposure given default. WWR means this is higher than EE.
- Unilateral CVA (discrete sum)
- CVA = LGD × Σ [ DF(tᵢ) × EE(tᵢ) × PD(tᵢ₋₁, tᵢ) ]
- LGD = 1 − recovery. EE is expected exposure (positive part only). PD is the marginal default probability in each interval, under risk-neutral measure.
- Credit triangle
- λ ≈ s ÷ LGD
- s is the CDS spread, λ the hazard rate. Use for a quick risk-neutral PD when the question gives a spread.
- Marginal PD from a hazard rate
- PD(tᵢ₋₁, tᵢ) = e^(−λ·tᵢ₋₁) − e^(−λ·tᵢ)
- Gives default probability within one period, for use in the CVA sum.
- Approximate CVA with flat inputs
- CVA ≈ s × EPE × risky annuity
- Flat spread and flat exposure. It is the basis for sizing a CDS hedge quickly.
- CDS hedge notional (spread hedge)
- Notional ≈ CS01 of CVA ÷ CS01 per unit of CDS notional
- With a maturity-matched CDS and flat inputs this is roughly the EPE. It is only a hedge of spread risk, not of exposure changes.
- BA-CVA reduced version
- Capital = DS × K_reduced, with DS = 0.65
- DS is the discount scalar. The reduced version gives no credit for hedges.
- FVA (approximate)
- FVA ≈ funding spread × EPE × T − funding spread × ENE × T
- The first term is the funding cost on positive exposure. The second is the benefit on negative exposure (ENE). Discounting ignored.
- MVA (approximate)
- MVA ≈ funding spread × average expected initial margin × T
- Applies to margin posted that the bank must fund.
- KVA (approximate)
- KVA ≈ hurdle rate × average expected capital × T
- Capital is regulatory capital over the trade life. The hurdle rate is the shareholders' required return, often net of what capital earns.
Quick revision
- Current exposure is the greater of the current replacement value and zero.
- Expected exposure is the average positive exposure at a future date; PFE is a high percentile of exposure at that date.
- Netting applies only under an enforceable netting agreement and lowers exposure to the net positive amount.
- Collateral lowers exposure but leaves a residual risk over the margin period of risk.
- Unilateral CVA ≈ LGD × Σ discounted EE × marginal default probability, where LGD = 1 − recovery rate.
- Unilateral CVA is a cost to you; it reduces the value of the portfolio.
- Bilateral CVA = CVA − DVA, where DVA is the gain from your own default risk.
- DVA rises when your own credit spread widens, which is why it is criticised.
- Wrong-way risk means exposure rises as the counterparty's credit quality falls; right-way risk is the reverse.
- Wrong-way risk makes CVA larger than an independence-based calculation would show.
- A CDS hedge covers credit spread risk in CVA but not the exposure (market) risk.
- Funding adjustments reflect the cost of funding uncollateralised positions and are separate from CVA.
Common mistakes
- Averaging only the positive outcomes to get EE, or averaging V itself. Fix: EE is E[max(V, 0)] over all scenarios. Negative scenarios count as zero, not dropped.
- Treating PFE as an average. Fix: PFE is a percentile. It is used for limits. EE is a mean. It is used for pricing CVA.
- Netting positive and negative values across different netting agreements. Fix: Net only within one enforceable master agreement. Floor each set at zero, then add the sets.
- Forgetting to floor the net value at zero. Fix: Exposure is always max(net value, 0). A negative net means you owe the counterparty, so your credit exposure is zero.
- Using cumulative default probability for every bucket Fix: Use the marginal PD for each interval, the difference between consecutive cumulative values. Using cumulative values counts the same default several times.
- Forgetting to multiply by LGD Fix: PD × EE is expected exposure at default. Multiply by 1 − R to get the loss.
- Adding DVA to CVA as if both are losses. Fix: CVA is a cost and DVA is a benefit. Bilateral CVA charge = CVA − DVA.
- Using the counterparty's default probability in the DVA calculation. Fix: For DVA use your own default probability, your own LGD and expected negative exposure.
- Treating wrong-way risk as a higher default probability alone. Fix: Remember it is the dependence between exposure and default. Exposure must rise as default likelihood rises.
- Mixing up specific and general wrong-way risk. Fix: Specific has a direct link in the trade, such as a put on the counterparty's own stock. General comes from broad factors such as macro or sector conditions.
Exam tips
- Read the metric name twice. Mean, percentile, time average and running-maximum average are four different answers.
- Wrong options often come from skipping the zero floor or the running maximum. Check both before choosing.
- Know the uses: EE feeds CVA, PFE feeds limits, effective EPE feeds regulatory EAD.
- Expect interpretation questions, such as why a swap's exposure profile rises then falls while an option's is highest at start. Link the shape to time to maturity and volatility.
- Keep the sanity checks ready: PFE ≥ EE at the same date, and effective EPE ≥ EPE.
- Always check whether netting is stated to be legally enforceable. If the question says it is not, compute exposure trade by trade.
- Read the CSA terms in order: threshold first, then MTA, then independent amount. Many MCQ distractors come from skipping one.
- For MPOR questions, expect square-root-of-time scaling. Match the horizon to the days given, such as 10 business days for daily margining of liquid OTC trades under many regimes, only if the question states it.