Topics 27-30 Flashcards
Describe and calculate the following metrics for credit exposure: expected mark-to-market, expected exposure, potential future exposure
- Expected mark to market (MtM) is the expected value of a transaction at a given point in the future. Long measurement periods as well as the specifics of cash flows may cause large differences between current MtM and expected MtM.
- Expected exposure (EE) is the amount that is expected to be lost if there is positive MtM and the counterparty defaults. Expected exposure is larger than expected MtM because the latter considers both positive and negative MtM values.
- Potential future exposure (PFE) is an estimate of MtM value at a specific point in the future. It is usually based on a high confidence level, taking into account the worst-case scenario. The current MtM may follow a number of different possible paths into the future, so a probability distribution of PFE can be derived, similar to the one shown in Figure 1. Positive MtM (the shaded area in Figure 1) is the part of the exposure that is at risk. Any points in this shaded area can represent PFE.
- In other words, PFE is the worst exposure that could occur at a given time in the future at a given confidence level. Potential future exposure represents a “gain” amount because it is the amount at risk if the counterparty defaults. Maximum PFE is the highest PFE value over a stated time frame.
Describe and calculate the following metrics for credit exposure: expected positive exposure and negative exposure, effective exposure, and maximum exposure
- Expected positive exposure (EPE) is the average EE through time. Expected positive exposure is a useful single amount to quantify exposure.
- Negative exposure, which is the exposure from the counterparty’s point of view, is represented by negative future values. The expected negative exposure (ENE) and the negative expected exposure (NEE) are the exact opposite of EPE and EE.
- The effective EE and effective EPE measures are meant to properly capture rollover risk for short-term transactions (under one year). Effective EE is equal to nondecreasing EE. Effective EPE is the average of the effective EE.
Compare the characterization of credit exposure to VaR methods and describe additional considerations used in the determination of credit exposure
The characterization of credit exposure is similar to the characterization of VaR, although additional considerations are relevant to credit exposure, described as follows:
- Application: Credit exposure is defined for both pricing and risk management, whereas VaR is just for risk management. As a result, quantifying credit exposure is more difficult and may result in different calculations for both pricing and risk management purposes.
- Time horizon: VaR models are based on a relatively short time horizon, whereas credit exposure must be defined over many time horizons. The trend (i.e., drift) of market variables, their underlying volatility, and their levels of co-dependence become relevant for credit exposure, whereas for VaR, these elements are irrelevant due to the short time horizon. Also, while VaR tends to ignore future contractual payments and changes such as exercise decisions, cash flows, and cancellations, credit exposure must take these elements into account because they tend to create path dependency (i.e., credit exposure in the future depends on an event occurring in the past).
- Risk mitigants: Netting and collateral are examples of risk mitigants, designed to reduce the level of credit exposure. In order to estimate future levels of credit exposure, these mitigants need to be taken into account. Netting requires that the proper rules be applied, which may add a level of complexity. Future collateral adds a significant element of subjectivity, as the type of collateral and time to receive collateral must all be modeled even though they may be unknown.
Identify factors that affect the calculation of the credit exposure profile and summarize the impact of collateral on exposure
The credit exposure profile is impacted by several factors, including:
- Future uncertainty: In situations where there is a single payout at the end of the life of a contract, uncertainty regarding the value of the final exchange increases over time.
- Periodic cash flows: Unlike the situation where there is a single payout, when cash flows occur regularly, the negative impact of the future uncertainty factor is reduced. However, additional risk exists when periodic cash flows are not equal in each period and are based on variables that may change as is often the case in an interest rate swap with variable interest rates.
- Combination of profiles: This exists when the credit exposure of a product results from the combination of multiple underlying risk factors. A cross-currency swap (which combines a foreign exchange forward trade with an interest rate swap) is a good example of this factor.
- Optionality: Exercise decisions (e.g., a swap-settled interest rate swaption) will have an impact on credit exposure. Collateral will also have a significant impact on credit exposure, as it typically reduces the level of credit exposure.
In addition, the reality is that risk is not removed entirely even with collateral due to factors such as delays in receiving collateral, variations in collateral value (i.e., when the collateral is something other than cash), the granularity effect (i.e., key parameters prevent asking for all of the collateral actually required), and the path dependency of collateral (i.e., the amount called for depends on the amount collected in the past).
Identify typical credit exposure profiles for various derivative contracts and combination profiles
- The PFE of bonds, loans, and repos are approximately equal to the notional value.
- Exposure profiles of swaps are typically characterized by a peak shape.
- The high volatility of FX rates, long maturities, and large final payments of notional value result in monotonically increasing exposures for foreign exchange products.
- Figure 8 provides an exposure profile for a long option position (with up-front premium) and illustrates the increase over time of the exposure until the option is exercised. The exact shape of the graph can change when the option is near, in, or out of the money. However, the increase over time is similar for all options due to the fact that the option can be deep in the money.
Explain how payment frequencies and exercise dates affect the exposure profile of various securities
Figure 10 illustrates that with unequal payments there is reduced exposure when payments are received more frequently than payments are made. Conversely, if a PFE were created for an interest rate swap where interest payments made were more frequent than interest payments received, it would have the reverse effect. In that case, the unequal payment PFE would show greater exposure than the equal payment PFE.
Explain the impact of netting on exposure, the benefit of correlation, and calculate the netting factor
It is also important to consider the relationship between netting and correlation. Positive correlations have lower netting benefits than negative correlations, with perfect positive correlation providing the least netting benefit. High positive correlations likely result in trades that are of the same sign, resulting in a small or zero netting benefit.
It is important to note that the netting benefit also depends on the initial MtM of transactions. For example, a trade with strong overall negative MtM under all scenarios will have a strong netting benefit by offsetting some or all of the positive MtM of other trades. Similarly, a trade with strong overall positive exposure under all scenarios will reduce the netting benefit by offsetting some or all of the negative MtM of other trades.
Explain the impact of collateralization on exposure, and assess the risk associated with the remargining period, threshold, and minimum transfer amount
When Party A has a positive exposure (e.g., receives cash flows in a swap transaction from Party B), Party A is said to have credit exposure because Party B could default.
When calculating an exposure profile, a risk manager should understand the factors that affect the collaterals ability to reduce risk. Specifically, factors that affect the calculation of exposure include thresholds, minimum transfer amounts, rounding, initial margin, and the remargin period.
The remargin period, also known as the margin call frequency, is the period from which a collateral call takes place to when collateral is actually delivered.
Steps that enter into the calculation of the number of days in the remargin period are as follows:
Step 1: Valuation/margin call: How long it takes to calculate current exposure to the counterparty and the market value of the collateral. These calculations help to determine if a valid call may be made.
Step 2 : Receiving collateral: The period between when the counterparty receives the request and when it releases the collateral.
Step 3 : Settlement: The time it takes to sell the collateral for cash.
Step 4: Grace period: The amount of time afforded to the counterparty obligated to deliver the collateral in the event that the collateral is not received by the requesting counterparty after the call. This may be a short window of time before the delivering counterparty would be considered in default for a failure-to-pay credit event.
Step 5: Liquidation/close-out and re-hedge: The time needed to liquidate the collateral, close out, and re-hedge positions.
Measuring Exposure During the Remargin Period
Potential disadvantages of PFE calculations
Potential disadvantages of PFE calculations include:
- It assumes a strongly collateralized position. PFE fails to work under a large threshold or minimum transfer amount, which produces a partially uncollateralized exposure.
- The analysis fails to account for the uncertainty of collateral volatility.
- Liquidity and liquidation risks are not considered.
- Volatility may differ from expected or implied volatility at the time of the collateral call and may not assume counterparty default.
- Wrong-way risk is not taken into account.
Collateral volatility
Collateral volatility must be calculated when a decline in the value of noncash collateral has the potential to create undercollateralization.
When there is no correlation between the volatility of the underlying exposure and that of the collateral, overall volatility is calculated as follows:
(variance of noncash collateral + variance of underlying exposure)0.5
This volatility measure would be used in the PFE formula to reflect the additive exposure of the collateral and volatility of the underlying exposure.
Modeling Collateral
Quantifying how much collateral reduces credit exposure is important. The risks that arise during the process of collateralizing exposure are:
- Collateralization may be deficient due to terms in the collateral agreement, such as threshold, minimum transfer amount, and rounding. These factors may result in less than full collateralization.
- Exposure could increase between margin calls. The increased amount of exposure may not be collateralized.
- Collateral is path-dependent. This means that the amount of collateral requested depends on how much was requested in the past.
Certain parameters impact the effectiveness of collateral in lessening credit exposure. These parameters are as follows:
- Remargin period: the time between the call for collateral and its receipt. The remargin period will be significantly longer than the actual legal margin call frequency; e.g., 10 days versus 1 day.
- Threshold: an exposure level below which collateral is not called. It represents an amount of uncollateralized exposure. The threshold represents an amount of uncollateralized exposure: If an exposure is above the threshold, only the incremental exposure will be collateralized
- Minimum transfer amount: the minimum quantity or block in which collateral may be transferred. Quantities below this amount represent uncollateralized exposure as well.
- Initial margin: an amount posted independently of any subsequent collateralization. This is also referred to as the initial margin. It is also called an independent amount.
- Rounding: the process by which a collateral call amount will be adjusted (rounded) to a certain increment.
Figuring out how much exposure should be collateralized at a given point in time involves several critical assumptions.
- Remargin period: how long before collateral is received from when it is first requested.
- Calculation of collateral called or returned: this exercise utilizes the aforementioned parameters.
- Calculation of collateralized exposure at each point in time: all amounts called for collateral less the remargin period.
Risk-Neutral vs. Real Probability Measures
- A risk-neutral parameter is often assumed in arbitrage pricing models where hedging is used. Conversely, when exposures are calculated for risk management purposes, the parameters are not risk-neutral but are based on real historical data and common sense. Parameters used for drifts and volatilities are market-driven (i.e., risk-neutral) and may not always reflect historical data or expected events.
- The length of data to use for parameter estimation has important implications. A shorter data sample window results in poor statistics, while a longer data sample window gives more weight to older, less relevant data.
SPV
A special purpose vehicle (SPV) is an off-balance sheet, bankruptcy-remote entity that can be created by various originators including investment banks and insurance companies. The general idea of an SPV is to create an entity that is separate from its originator but who holds such a high credit quality that default risk is theoretically negligible. Once created, an SPV will borrow money and purchase a series of assets from the originator. The SPV will then repackage the purchased assets into a structured note, like a collateralized debt obligation (CDO), and then sell these assets to investors. The originator will often need to provide a guarantee for the SPV as a counterparty. This may create a double default scenario where both the SPV and the originator are drawn into a counterparty solvency issue.
A special purpose vehicle, also sometimes called a special purpose entity (SPE), theoretically transforms counterparty risk into a type of legal risk. The legal risk is that a bankruptcy court might consolidate the assets of an SPV with their originator in the event of default. This would treat the SPV assets as if they had never been physically transferred off the originator’s books. This treatment will depend on jurisdiction, but U.S. courts have a history of consolidation rulings. Under this scenario, the goal of isolating the originator from counterparty risk with the SPV is often not realized.
DPC
A derivative product company (DPC) is an entity that evolved out of a need for over-thecounter (OTC) derivatives markets to manage counterparty risk. They commonly transact in credit default swaps (CDSs), equity derivatives, currency derivatives, and interest ratebased derivatives. A DPC is set up by a financial institution to obtain a AAA credit rating with separate capitalization from the originator. This puts further distance between a DPC and its originator. In this way, if the DPC originator were to fail, then the DPC would not be harmed. This provides a measure of enhanced protection for DPC counterparties.
Similar to an SPV, a DPC is established to be bankruptcy-remote from the originator. However, in the event of failure of the originator, a DPC is pre-arranged to either pass to another originator or to gradually unwind all mirrored transactions in an orderly fashion. Internal credit risk management guidelines also provide another layer of risk mitigation in a DPC. These restrictions often involve daily marking to market and collateral posting to limit risk exposures.