Why Collateral Value Is Not the Same as Collateral Credit
A collateral schedule may list assets with a substantial market value, yet the amount credited against a large-deductible obligation can be lower. A policy may discount values for price volatility, recognize that some assets could be difficult to convert promptly into funds, and limit the amount credited for assets concentrated with one issuer. The calculation therefore needs to distinguish the assets’ stated values from their eligible collateral value.
This tutorial uses a defined calculation convention: apply the asset’s valuation haircut to its market or face value, then apply any separate liquidity haircut to the value remaining. Sum the resulting values within each concentration group, and apply that group’s stated dollar cap. A collateral policy can prescribe a different order or other rules; calculations must follow the supplied policy rather than assume that every program uses this convention.
A haircut is a percentage reduction in value, not a payment or a loss estimate. If a $100,000 asset has a 5% valuation haircut, its value after that haircut is $95,000. A separate 2% liquidity haircut then applies to $95,000, not to the original $100,000. In this convention the combined reduction is \(h+l-hl\), because \(1-(1-h)(1-l)=h+l-hl\). It is not generally the sum \(h+l\).
A concentration cap is different from a haircut. It limits the amount credited for a group after the applicable asset-level adjustments. It does not change the asset’s market value, and it does not create additional value in another group. For clarity, the examples use caps stated as dollar amounts. If a policy instead defines a cap as a percentage of a portfolio or obligation, that policy’s denominator and allocation rules must be specified before applying the cap.
From Adjusted Values to Exposure Measures
The collateral calculation is only one side of the comparison. Let \(G\) be the gross secured obligation being evaluated, before credit for collateral. The residual unsecured amount is \(U=\max(0,G-E)\), and the collateral surplus is \(S=\max(0,E-G)\). The coverage ratio is \(E/G\) when \(G>0\). These measures answer different questions: the ratio shows relative coverage, while \(U\) shows the dollar amount not covered under the stated valuation rules.
These are arithmetic measures under stipulated collateral terms, not forecasts of claim cost or guarantees of recovery. They assume the listed assets are eligible in the first place and that the supplied values, haircuts, liquidity adjustments, and caps are the applicable terms. Questions about legal enforceability, draw conditions, or the likelihood of a counterparty failing to pay require separate analysis.
Worked Example: Applying Two Haircuts and an Issuer Cap
A hypothetical program has a gross secured obligation of $250,000. Its collateral consists of $120,000 cash, an $80,000 government security, and a $60,000 corporate bond. The government security has a 2% valuation haircut and a 1% liquidity haircut. The corporate bond has an 8% valuation haircut and a 4% liquidity haircut. The bond’s issuer group has a $50,000 concentration cap. Cash has no haircut or cap. Calculate eligible collateral, coverage, and residual unsecured amount.
Method and assumptions. Use the stipulated sequential haircut convention and then apply the issuer cap. All amounts below are in thousands of dollars, so $250,000 is 250. No interest assumption, mortality assumption, or stochastic loss distribution is needed: the asset values and policy adjustments are stipulated.
Cash. Its adjusted value is \(120(1-0)(1-0)=120\).
Government security. After the valuation haircut, its value is \(80(1-0.02)=78.4\). After the liquidity haircut, its adjusted value is \(78.4(1-0.01)=77.616\).
Corporate bond. After the valuation haircut, its value is \(60(1-0.08)=55.2\). After the liquidity haircut, its adjusted value is \(55.2(1-0.04)=52.992\). Applying the $50,000 concentration cap gives eligible bond collateral of \(\min(52.992,50)=50\).
Total eligible collateral is \(120+77.616+50=247.616\), or $247,616. The coverage ratio is \(247.616/250=0.990464\), or 99.0464%. The residual unsecured amount is \(\max(0,250-247.616)=2.384\), or $2,384. The calculation checks: eligible collateral plus the residual amount equals the $250,000 obligation.
Common mistake avoided: Adding the two corporate-bond haircuts and applying a 12% reduction would give \(60(1-0.12)=52.8\), which is not the specified sequential result of 52.992. The correct adjusted value is found by applying each percentage to the value remaining at that step, and then applying the cap.
Why Sequential Haircuts Multiply
The sequential formula follows directly from what each percentage reduction is applied to. Start with market value \(M\). After a valuation haircut \(h\), the remaining value is \(M(1-h)\). A liquidity haircut \(l\) removes the fraction \(l\) of that remaining amount, leaving the fraction \(1-l\). Thus:
Expanding the product gives \(A=M(1-h-l+hl)\), so the total reduction as a fraction of the original value is \(h+l-hl\). The product formula is appropriate when the policy specifies that the second haircut applies to the post-first-haircut value. If a policy explicitly defines both haircuts as deductions from original market value, the formula would instead be \(M(1-h-l)\), subject to its own rules and limits. Do not substitute one convention for the other.
The concentration calculation is then a cap on adjusted values, not an additional percentage reduction on every asset. For a group with adjusted total \(T_g=\sum_{j\in g}A_j\), the credited amount is \(T_g\) if \(T_g\le C_g\), and \(C_g\) if \(T_g>C_g\). In the latter case, a further decline in one asset may initially leave eligible group collateral unchanged: the cap still binds. Once the adjusted total falls below the cap, subsequent declines reduce eligible collateral dollar for dollar, assuming no other rule changes.
Use the market value or eligible face value specified for each asset, with consistent units and valuation dates.
Apply each valuation haircut and liquidity adjustment in the order required by the terms. Record the adjusted value for each asset.
Sum adjusted values within each specified issuer or other policy group; do not apply one group’s cap to unrelated assets.
For each capped group, take the lesser of its adjusted total and its cap. Sum group credits to obtain total eligible collateral.
Calculate coverage, the residual unsecured amount, or the surplus using the gross obligation and total eligible collateral.
Concentration Limits and Market-Value Changes
A cap can make the response to a market-value movement piecewise rather than proportional. When a group’s adjusted total is above its cap, small declines may reduce only the uncredited excess; eligible collateral for that group remains at the cap. If a decline takes the adjusted total below the cap, the cap no longer protects the credited amount: further declines reduce eligible collateral directly. This distinction matters when evaluating how sensitive collateral coverage is to asset values.
The following comparison keeps the gross obligation fixed. That isolates the collateral valuation effect; if the obligation also changes, recalculate both sides rather than attributing the entire change in coverage to collateral.
Worked Example: A Market Decline That Releases a Concentration Cap
A hypothetical program has a $200,000 gross secured obligation. Issuer A has two bonds with market values of $90,000 and $70,000. Each has a 5% valuation haircut and a 2% liquidity haircut, and Issuer A’s concentration cap is $130,000. Issuer B has a $50,000 bond with a 10% valuation haircut, a 5% liquidity haircut, and a $60,000 cap. There is also $30,000 cash with no adjustment. First calculate eligible collateral, then recalculate if Issuer A’s $90,000 bond falls in value to $60,000. All values are in thousands of dollars; no interest, mortality, or stochastic loss assumption is needed.
Method. Calculate the adjusted value of each bond using the sequential convention, aggregate by issuer, and then apply each issuer’s cap. The gross obligation remains 200 in both calculations.
Initial Issuer A value. The combined market value is \(90+70=160\). The common sequential factor is \((1-0.05)(1-0.02)=0.95(0.98)=0.931\). Thus the adjusted group value is \(160(0.931)=148.96\). The cap reduces eligible Issuer A collateral to \(\min(148.96,130)=130\).
Issuer B and cash. Issuer B’s adjusted value is \(50(1-0.10)(1-0.05)=50(0.90)(0.95)=42.75\), below its cap of 60. Cash contributes 30. Initial total eligible collateral is \(130+42.75+30=202.75\), or $202,750. The coverage ratio is \(202.75/200=1.01375\), or 101.375%. The surplus is \(202.75-200=2.75\), or $2,750, and the residual unsecured amount is zero.
After the value decline. Issuer A’s market-value total becomes \(60+70=130\). Its adjusted total is \(130(0.931)=121.03\), now below the $130,000 cap. Issuer A therefore contributes 121.03 rather than 130. Issuer B and cash are unchanged, so new total eligible collateral is \(121.03+42.75+30=193.78\), or $193,780. Coverage is \(193.78/200=0.9689\), or 96.89%. Residual unsecured exposure is \(200-193.78=6.22\), or $6,220.
The decline reduces eligible collateral by \(202.75-193.78=8.97\), not by the full market-value decline of 30. The first part of the decline reduces Issuer A’s uncredited amount while the cap binds; only after the adjusted total falls below the cap does the credited amount fall. The final check is \(193.78+6.22=200\), equal to the gross obligation.
Common mistake avoided: Applying Issuer A’s $130,000 cap to its raw market value and then adding other collateral would ignore both haircuts. The cap is applied to the group’s adjusted value, not its unadjusted market value.
Liquidity Adjustments, Reporting, and Practical Checks
A liquidity adjustment is intended to reflect a policy’s treatment of how readily an asset can be converted into funds, not to duplicate a valuation haircut without justification. The policy should make clear whether the adjustments are sequential, whether particular assets have fixed haircuts, and how concentration groups and caps are defined. A calculation cannot resolve ambiguity in those terms by itself.
For a sound calculation, keep a record of each asset’s value, valuation haircut, liquidity haircut, adjusted value, concentration group, and cap. Reconcile the sum of adjusted values before caps to the total after caps. If total eligible collateral exceeds the obligation, report the surplus rather than a negative unsecured amount. If it falls short, report the shortfall as a positive residual amount.
- Keep units consistent. Do not add dollars to thousands of dollars or apply a dollar cap to a value expressed in another unit without conversion.
- Do not double-count. Apply each stipulated haircut once, then apply concentration limits at the group level.
- Check whether a cap binds. Compare the adjusted group total with the cap; raw market value alone does not determine whether the cap applies.
- Separate the obligation from the collateral. Haircuts change eligible collateral, while a change in the gross obligation changes the amount being secured.
Check Your Understanding
For each hypothetical calculation, apply the stated sequential haircut convention and concentration cap. Amounts are in thousands of dollars unless stated otherwise.
- A government security has a market value of $45,000, a 2% valuation haircut, and a 1% liquidity haircut. What is its adjusted value? (Answer: $43,659.)
- Two bonds from one issuer have values of 60 and 40, each with a 5% valuation haircut and a 2% liquidity haircut. The issuer cap is 90. A separate cash balance of 15 has no adjustment. What is total eligible collateral? (Answer: $105,000.)
- A secured obligation is 125. Collateral consists of cash of 20, an asset of 70 with a 10% valuation haircut and 5% liquidity haircut, and an asset of 50 with a 4% valuation haircut and 2% liquidity haircut. There are no concentration caps. Find eligible collateral, coverage, and residual unsecured amount. (Answer: Eligible collateral is $126,890; coverage is 101.512%; residual unsecured amount is $0.)
- A hypothetical program has an obligation of 175. Issuer A holds assets of 80 and 70, each with a 5% valuation haircut and 2% liquidity haircut, subject to a cap of 125. Issuer B holds 40 with a 10% valuation haircut and 5% liquidity haircut, subject to a cap of 50. Cash is 10. Find total eligible collateral and the residual unsecured amount. (Answer: Eligible collateral is $169,200; residual unsecured amount is $5,800.)
- An obligation is 205. An issuer group has assets of 100 and 50, each with an 8% valuation haircut and 3% liquidity haircut, and a cap of 120. There is also a government security worth 60 with a 2% valuation haircut and 1% liquidity haircut, plus cash of 20. Find initial eligible collateral and the unsecured amount. Then find the unsecured amount if the 100-value issuer asset declines by 25%, with all other values and terms unchanged. (Answer: Initially, eligible collateral is $198,212 and unsecured amount is $6,788. After the decline, eligible collateral is $189,762 and unsecured amount is $15,238; unsecured exposure increases by $8,450.)