Risk Management
Risk Management
Information Requirement 
By 
A.K.Nag 
To-days Agenda 
 Risk Management and Basel II- an overview 
 Analytics of Risk Management 
 Information Requirement and the need for 
building a Risk Warehouse 
 Roadmap for Building a Risk Warehouse  
   
 Intelligent management of risk 
will be the foundation of a 
successful financial institution 
 In the future . . . 
Concept of Risk 
 Statistical Concept 
 Financial concept 
Statistical Concept 
 We have data x from a sample space .  
 Model- set of all possible pdf of  indexed by . 
 Observe x  then decide about . So have a decision 
rule.  
 Loss function L(,a): for each action a in A. 
 A decision rule-for each x what action a. 
  A decision rule (x)- the risk function is defined 
as  R(, ) =E
L(, (x)). 
 For a given , what is the average loss that will be 
incurred if the decision rule (x) is used  
Statistical Concept- contd. 
 We want a decision rule that has a small expected 
loss 
 If we have a prior defined over the parameter 
space of  , say () then Bayes risk is defined as 
B(, )=E
(R(, )) 
Financial Concept 
 We are concerned with L(,a). For a given 
financial asset /portfolio what is the amount we 
are likely to loose over a time horizon with what 
probability. 
Financial 
Risks 
Operational Risk 
Market Risk 
Credit Risk 
   
Types of Financial Risks 
 Risk is multidimensional 
Hierarchy of  Financial Risks 
Portfolio 
Concentration  
Risk 
Transaction Risk 
Counterparty 
Risk 
Issuer Risk 
Trading Risk 
Gap Risk 
Equity Risk 
Interest Rate Risk 
Currency Risk 
Commodity Risk 
Financial 
Risks 
Operational 
Risk 
Market Risk 
Credit Risk 
Specific 
Risk 
General 
Market 
 Risk 
Issue Risk 
* From  Chapter-1, Risk Management by Crouhy, Galai and Mark 
Response to Financial Risk 
 Market response-introduce new products 
 Equity futures 
 Foreign currency futures 
 Currency swaps 
 Options 
  Regulatory response 
 Prudential norms 
 Stringent Provisioning norms 
 Corporate governance norms 
Evolution of Regulatory environment 
 G-3- recommendation in 1993 
 20 best practice price risk management 
recommendations for dealers and end-users of 
derivatives 
 Four recommendations for legislators, regulators and 
supervisors 
 1988 BIS Accord 
 1996 ammendment 
 BASELII 
BASEL-I 
 Two minimum standards 
 Asset to capital multiple 
 Risk based capital ratio (Cooke ratio) 
 Scope is limited 
 Portfolio effects missing- a well diversified portfolio is 
much less likely to suffer massive credit losses 
 Netting is absent 
 No market or operational risk 
 
 
BASEL-I  contd.. 
 Calculate risk weighted assets for on-balance sheet 
items 
 Assets are classified into categories 
 Risk-capital weights are given for each category 
of assets 
 Asset value is multiplied by weights 
 Off-balance sheet items are expressed as credit 
equivalents 
Minimum 
Capital 
Requirement 
Three Basic Pillars 
Supervisory  
Review Process 
Market  
Discipline  
Requirements 
The New Basel Capital Accord 
Standardized 
Internal Ratings 
Credit Risk Models 
Credit Mitigation 
Market Risk 
Credit Risk 
Other Risks 
Risks 
Trading Book 
Banking Book 
Operational 
Other 
Minimum Capital Requirement 
Pillar One 
Workhorse of Stochastic Process  
 Markov Process 
 Weiner process (dz)  
 Change  z during a small time period(t) is z=(t) 
 z for two different short intervals are independent 
 Generalized Wiener process 
 dx=adt+bdz 
 Ito process 
 dx=a(x,t)+b(x,t)dz 
 Itos lemma 
 dG=(G/x*a+G/t+1/2*
2
G/
2
x
2
*b
2) 
dt 
+
G/x*b*dz 
Credit Risk 
1. Minimum Capital Requirements-    Credit 
Risk     (Pillar One) 
 Standardized approach  
  (External Ratings) 
 Internal ratings-based approach 
 Foundation approach 
 Advanced approach 
 Credit risk modeling 
  (Sophisticated banks in the future) 
Minimum 
Capital 
Requirement 
Evolutionary Structure of the Accord 
Credit Risk Modeling ? 
Standardized Approach 
Foundation IRB Approach 
Advanced IRB Approach 
Standardized Approach 
 
   Provides Greater Risk Differentiation than 1988 
   Risk Weights based on external ratings 
   Five categories [0%, 20%, 50%, 100%, 150%] 
   Certain Reductions 
 e.g. short term bank obligations  
  Certain Increases  
 e.g.150% category for lowest  rated obligors 
The New Basel Capital Accord 
Standardized Approach 
External Credit 
Assessments 
Sovereigns  Corporates 
Public-Sector 
Entities 
Banks/Securities 
Firms 
Asset 
Securitization 
Programs 
Based on assessment of external credit assessment 
institutions 
Option 2
2
 
Assessment 
Claim 
AAA to 
AA- 
A+ to A-  BBB+ to 
BBB- 
BB+ to 
B- 
Below B-  Unrated 
Sovereigns  0%  20%  50%  100%  150%  100% 
20%  50%  50%  100%  150% 
100% 
Banks 
Option 1
1
  20%  50% 
3 
100% 
3 
100% 
3 
150% 
50% 
3 
Corporates  20%  100%  100%  100%  150%  100% 
1
 Risk weighting based on risk weighting of sovereign in which the bank is incorporated. 
2
 Risk weighting based on the assessment of the individual bank. 
3
 Claims on banks of a short original maturity, for example less than six months, 
would receive a weighting that is one category more favourable than the usual risk 
weight on the banks claims 
. 
Standardized Approach: 
New Risk Weights (June 1999) 
Option 2
2
 
Assessment 
Claim 
AAA to 
AA- 
A+ to A-  BBB+ to 
BBB- 
BB+ to 
BB- (B-) 
Below BB- 
(B-) 
Unrated 
Sovereigns  0%  20%  50%  100%  150%  100% 
20%  50% 
50% 
100%  150% 
100% 
Banks 
Option 1
1
  20%  50% 
3 
100% 
3 
100% 
3 
150% 
50% 
3 
Corporates  20% 
50%(100%) 
100%  100%  150%  100% 
1
 Risk weighting based on risk weighting of sovereign in which the bank is incorporated. 
2
 Risk weighting based on the assessment of the individual bank. 
3
 Claims on banks of a short original maturity, for example less than six months, 
would receive a weighting that is one category more favourable than the usual risk 
weight on the banks claims 
. 
Standardized Approach: 
New Risk Weights (January 2001) 
Pillar 1 
Internal Ratings-Based Approach 
 Two-tier ratings system: 
 Obligor rating 
 represents probability of default by a borrower 
 Facility rating 
 represents expected loss of principal and/or interest 
    
98 Rules 
Internal 
Model 
Standardized 
Model 
Capital 
Market 
Credit 
Opportunities for a 
Regulatory Capital Advantage 
 Example:  30 year Corporate Bond 
Standardized Approach 
0 
1.6 
8 
16 
PER CENT 
A
A
A
 
A
A
 
A
+
 
A
-
 
B
B
B
 
B
B
+
 
B
B
-
 
B
 
C
C
C
 
RATING 
New standardized model 
Internal rating system & Credit VaR 
12 
1  2  3  4  4.5  5  5.5  6  7  6.5 
S & P : 
 
Internal Model- Advantages 
Example:  
Portfolio of  
100 $1 bonds  
diversified 
across 
industries 
Capital charge for specific risk (%)
 
Internal  
model
 
Standardized  
approach
 
AAA
 
0.26
 
1.6
 
AA
 
0.77
 
1.6
 
A
 
1.00
 
1.6
 
BBB
 
2.40
 
1.6
 
BB
 
5.24
 
8
 
B
 
8.45
 
8
 
CCC
 
10.26
 
8
 
Three elements: 
 Risk  Components [PD, LGD, EAD] 
 Risk Weight conversion function 
 Minimum requirements for the management of policy 
   and processes 
 Emphasis on full compliance 
 
Definitions; 
PD = Probability of default [conservative view of long run average (pooled) for borrowers assigned to a RR grade.] 
LGD = Loss  given default 
EAD = Exposure at default 
     Note: BIS is Proposing 75% for unused commitments 
EL = Expected Loss 
Internal Ratings-Based Approach 
Risk Components 
 
Foundation Approach 
  PD  set by Bank 
  LGD, EAD  set by Regulator 
50% LGD for Senior Unsecured 
Will be reduced by collateral (Financial or Physical) 
  
Advanced Approach 
  PD, LGD, EAD  all set  by Bank 
  Between 2004 and 2006: floor for advanced 
    approach @ 90% of foundation approach 
 
Notes 
Consideration is being given to incorporate maturity explicitly into the Advancedapproach 
Granularity adjustment will be made. [not correlation, not models] 
Will not recognize industry, geography. 
Based on distribution  of exposures by RR. 
Adjustment will increase or reduce capital based on comparison to a reference portfolio 
 [different for foundation vs. advanced.] 
 
Internal Ratings-Based Approach 
Expected Loss Can Be Broken Down Into Three Components 
 
EXPECTED 
LOSS 
 
Rs. 
= 
 
Probability of 
Default 
(PD) 
% 
x 
 
Loss Severity  
Given Default 
(Severity) 
% 
 
Loan Equivalent 
Exposure 
(Exposure) 
Rs 
x 
The focus of grading tools is on modeling PD 
What is the probability 
of the counterparty 
defaulting? 
If default occurs, how 
much of this do we 
expect to lose? 
If default occurs, how 
much exposure do we 
expect to have? 
Borrower Risk   Facility Risk Related 
Credit or Counter-party Risk 
 Credit risk arises when the counter-party to a financial 
contract is unable or unwilling to honour its obligation. It 
may take following forms 
 Lending risk- borrower fails to repay interest/principal. But more 
generally it may arise when the credit quality of a borrower 
deteriorates leading to a reduction in the market value of the loan. 
 Issuer credit risk- arises when issuer of a debt or equity security 
defaults or become insolvent. Market value of a security may 
decline with the deterioration of credit quality of issuers. 
 Counter party risk- in trading scenario 
 Settlement risk- when there is a one-sided-trade 
Credit Risk Measures 
 Credit risk is derived from the probability distribution of 
economic loss due to credit events, measured over some 
time horizon, for some large set of borrowers. Two 
properties of the probability distribution of economic loss 
are important; the expected credit loss and the unexpected 
credit loss. The latter is the difference between the 
potential loss at some high confidence level and expected 
credit loss. A firm should earn enough from customer 
spreads to cover the cost of credit. The cost of credit is 
defined as the sum of the expected loss plus the cost of 
economic capital defined as equal to unexpected loss.  
Contingent claim approach 
 Default occurs when the value of a companys 
asset falls below the value of outstanding debt 
 Probability of default is determined by the 
dynamics of assets. 
 Position of the shareholders can be described as 
having call option on the firms asset with a strike 
price equal to the value of the outstanding debt. 
The economic value of default is presented as a 
put option on the value of the firms assets.  
Assumptions in contingent claim 
approach 
 The risk-free interest rate is constant 
 The firm is in default if the value of its assets falls 
below the value of debt. 
 The default can occur only at the maturity time of 
the bond 
 The payouts in case of bankruptcy follow strict 
absolute priority  
Shortcoming of Contingent claim 
approach  
 A risk-neutral world is assumed 
 Prior default experience suggests that a firm 
defaults long before its assets fall below the value 
of debt. This is one reason why the analytically 
calculated credit spreads are much smaller than 
actual spreads from observed market prices. 
KMV Approach 
 KMV derives the actual individual probability of 
default for each obligor , which in KMV 
terminology is then called expected default 
frequency or EDF. 
 Three steps 
 Estimation of the market value and the volatility of the 
firms assets 
 Calculation of the distance-to-default (DD) which is an 
index measure of default risk 
 Translation of the DD into actual probability of default 
using a default database. 
An Actuarial Model: CreditRisk+ 
 The derivation of the default loss distribution in 
this model comprises the following steps 
 Modeling the frequencies of default for the portfolio 
 Modeling the severities in the case of default 
 Linking these distributions together to obtain the 
default loss distribution 
The CreditMetrics Model 
 Step1  Specify the transition matrix 
 Step2-Specify the credit risk horizon 
 Step3-Specify the forward pricing model 
 Step4  Derive the forward distribution of the 
changes in portfolio value 
 
IVaR and DVaR  
 IVaR-incremental vaR  -it measures the 
incremental impact on the overall VaR of the 
portfolio of adding or eliminating an asset 
 I is positive when the asset is positively correlated with 
the rest of the portfolio and thus add to the overall risk 
 It can be negative if the asset is used as a hedge against 
existing risks in the portfolio 
 DeltaVaR(DVaR)  - it decomposes the overall risk 
to its constituent assetss contribution to overall 
risk 
Information from Bond Prices 
 Traders regularly estimate the zero curves for 
bonds with different credit ratings 
 This allows them to estimate probabilities of 
default in a risk-neutral world 
Typical Pattern  
(See Figure 26.1, page 611) 
Spread 
over 
Treasuries 
Maturity 
Baa/BBB 
A/A 
Aa/AA 
Aaa/AAA 
The Risk-Free Rate 
 Most analysts use the LIBOR rate as the risk-free 
rate 
 The excess of the value of a risk-free bond over a 
similar corporate bond equals the present value of 
the cost of defaults 
 
Example (Zero coupon rates; continuously 
compounded) 
  
Maturity
(years)
Risk-free
yield
Corporate
bond yield
1 5% 5.25%
2 5% 5.50%
3 5% 5.70%
4 5% 5.85%
5 5% 5.95%
Example continued 
  One-year risk-free bond (principal=1) sells for 
 
  One-year corporate bond (principal=1) sells for 
    
  or at a 0.2497% discount 
  This indicates that the holder of the corporate bond expects 
to lose 0.2497% from defaults in the first year 
    
e
   
=
0 05 1
0951229
.
.
e
   
=
0 0525 1
0948854
.
.
Example continued 
 Similarly the holder of the corporate bond expects 
to lose 
 
 
   or 0.9950% in the first two years 
 Between years one and two the expected loss is 
0.7453% 
 
e e
e
         
   
  =
0 05 2 0 0550 2
0 05 2
0009950
. .
.
.
Example continued 
 Similarly the bond holder expects to lose 2.0781% 
in the first three years; 3.3428% in the first four 
years; 4.6390% in the first five years 
 The expected losses per year in successive years 
are 0.2497%, 0.7453%, 1.0831%, 1.2647%, and 
1.2962% 
Summary of Results  
(Table 26.1, page 612) 
Maturity 
(years) 
Cumul. Loss. 
% 
Loss 
During Yr (%) 
1  0.2497  0.2497 
2  0.9950  0.7453 
3  2.0781  1.0831 
4  3.3428  1.2647 
5  4.6390  1.2962 
 
 
Recovery Rates 
(Table 26.3, page 614. Source: Moodys Investors Service, 2000) 
Class  Mean(%)  SD (%) 
Senior Secured  52.31  25.15 
Senior Unsecured  48.84  25.01 
Senior Subordinated  39.46  24.59 
Subordinated  33.71  20.78 
Junior Subordinated  19.69  13.85 
 
 
Probability of Default Assuming No 
Recovery 
T T y T y
T T y
T T y T T y
e T Q
or
  e
  e e
T Q
)] ( ) ( [
) (
) ( ) (
*
*
*
1 ) (
) (
 
=
Where y(T): yield on a T-year corporate zero-coupon bond 
Y
*
(T): Yield on a T-year risk free zero coupon bond 
Q(T): Probability that a corporation would default between time zero and T 
Probability of Default 
  
0.025924 and 0.025294, 0.021662, 0.014906,
0.004994, are 5 and 4, , 3 2, 1, years in default of
  ies probabilit example, our in 0.5 Rate Rec  If
Rate Rec. - 1
Loss% Exp.
Def of Prob
Loss% Exp. Rate) Rec. - (1 Def. of Prob.
=
=
= 
Large corporates and specialised lending  
Characteristics of these sectors 
 Relatively large exposures to individual obligors 
 Qualitative factors can account for more than 50% of the risk of obligors 
 Scarce number of defaulting companies  
 Limited historical track record from many banks in some sectors 
 
Statistical models are NOT applicable in these sectors: 
 Models can severely underestimate the credit risk profile of obligors given the low 
proportion of historical defaults in the sectors. 
 Statistical models fail to include and ponder qualitative factors. 
 Models results can be highly volatile and with low predictive power. 
 
To build an internal rating system for Basel II you need: 
1. Consistent rating methodology across asset classes 
2. Use an expected loss framework  
3. Data to calibrate Pd and LGD inputs 
4. Logical and transparent workflow desk-top application 
5. Appropriate back-testing and validation. 
 
Six Organizational Principles for 
Implementing IRB Approach 
 All credit exposures have to be rated. 
 The credit rating process needs to be segregated from the loan 
approval process 
 The rating of the customer should be the sole determinant of all 
relationship management and administration related activities. 
 The rating system must be properly calibrated and validated 
 Allowance for loan losses and capital adequacy should be 
linked with the respective credit rating 
 The rating should recognize the effect of credit risk mitigation 
techniques 
Credit Default Correlation 
 The credit default correlation between two 
companies is a measure of their tendency to 
default at about the same time 
 Default correlation is important in risk 
management when analyzing the benefits of credit 
risk diversification 
 It is also important in the valuation of some credit 
derivatives 
Measure 1 
 One commonly used default correlation measure 
is the correlation between 
1. A variable that equals 1 if company A defaults 
between time 0 and time T and zero otherwise 
2. A variable that equals 1 if company B defaults 
between time 0 and time T and zero otherwise 
 The value of this measure depends on T. Usually 
it increases at T increases. 
Measure 1 continued 
  Denote Q
A
(T) as the probability that company A 
will default between time zero and time T, Q
B
(T) 
as the probability that company B will default 
between time zero and time T, and P
AB
(T) as the 
probability that both A and B will default. The 
default correlation measure is 
 
] ) ( ) ( ][ ) ( ) ( [
) ( ) ( ) (
) (
2 2
T Q T Q T Q T Q
T Q T Q T P
T
B B A A
B A AB
AB
 
  
= |
Measure 2 
 Based on a Gaussian copula model for time to default.  
 Define t
A
 and t
B
 as the times to default of A and B 
 The correlation measure, 
AB 
, is the correlation between  
u
A
(t
A
)=N
-1
[Q
A
(t
A
)] 
  and 
u
B
(t
B
)=N
-1
[Q
B
(t
B
)] 
  where N is the cumulative normal distribution function 
 
 
Use of Gaussian Copula  
 The Gaussian copula measure is often used in 
practice because it focuses on the things we are 
most interested in (Whether a default happens and 
when it happens) 
 
 Suppose that we wish to simulate the defaults for 
n companies . For each company the cumulative 
probabilities of default during the next 1, 2, 3, 4, 
and 5 years are 1%, 3%, 6%, 10%, and 15%, 
respectively  
Use of Gaussian Copula continued 
 We sample from a multivariate normal distribution 
for each company incorporating appropriate 
correlations 
 N 
-1
(0.01) = -2.33, N 
-1
(0.03) = -1.88,  
  N 
-1
(0.06) = -1.55, N 
-1
(0.10) = -1.28, 
  N 
-1
(0.15) = -1.04 
Use of Gaussian Copula continued 
 When sample for a company is less than  
  -2.33, the company defaults in the first year 
 When sample is between -2.33 and -1.88, the company defaults in the 
second year 
 When sample is between -1.88 and -1.55, the company defaults in the 
third year 
 When sample is between -1,55 and -1.28, the company defaults in the 
fourth year 
 When sample is between -1.28 and -1.04, the company defaults during 
the fifth year 
 When sample is greater than -1.04, there is no default during the first 
five years  
Measure 1 vs Measure 2 
   
 
 
  normal te multivaria be to assumed be can times survival d transforme
  because considered are companies many  when use to easier much is It
  1. Measure than higher tly  significan usually  is 2 Measure
function. on distributi
y  probabilit normal bivariate cumulative the is where
and
: versa vice and 2 Measure from calculated be can 1 Measure
M
T Q T Q T Q T Q
T Q T Q T u T u M
T
T u T u M T P
B B A A
B A AB B A
AB
AB B A AB
] ) ( ) ( ][ ) ( ) ( [
) ( ) ( ] ); ( ), ( [
) (
] ); ( ), ( [ ) (
2 2
 
   
= |
 =
Modeling Default Correlations 
   
  Two alternatives models of default correlation are: 
 Structural model approach 
 Reduced form approach 
  
Market Risk 
Market Risk 
 Two broad types- directional risk and relative 
value risk. It can be differentiated into two related 
risks- Price risk and liquidity risk. 
 Two broad type of measurements 
 scenario analysis 
 statistical analysis 
Scenario Analysis 
 A scenario analysis measures the change in market 
value that would result if market factors were 
changed from their current levels, in a particular 
specified way. No assumption about probability of 
changes is made. 
 A Stress Test is a measurement of the change in 
the market value of a portfolio that would occur 
for a specified unusually large change in a set of 
market factors. 
Value at Risk 
 A single number that summarizes the likely loss in 
value of a portfolio over a given time horizon with 
specified probability 
 C-VaR- Expected loss conditional on that the 
change in value is in the left tail of the distribution 
of the change. 
 Three approaches 
 Historical simulation 
 Model-building approach 
 Monte-Carlo simulation 
 
Historical Simulation 
 Identify market variables that determine the 
portfolio value 
 Collect data on movements in these variables for a 
reasonable number of past days. 
 Build scenarios that mimic changes over the past 
period 
 For each scenario calculate the change in value of 
the portfolio over the specified time horizon 
 From this empirical distribution of value changes 
calculate VaR. 
Model Building Approach 
 Consider a portfolio of n-assets 
 Calculate mean and standard deviation of change 
in the value of portfolio for one day.  
 Assume normality 
 Calculate VaR. 
Monte Carlo simulation 
 Calculate the value the portfolio today  
 Draw samples from the probability distribution of 
changes of the market variables 
 Using the sampled changes calculate the new 
portfolio value and its change 
 From the simulated probability distribution of 
changes in portfolio value calculate VaR. 
 
Pitfalls- Normal distribution based VaR 
 Normality assumption may not be valid for tail 
part of the distribution 
 VaR of a portfolio is not less than weighted sum 
of VaR of individual assets ( not sub-additive). It 
is not a coherent measure of Risk. 
 Expected shortfall conditional on the fact that loss 
is more than VaR is a sub-additive measure of 
risk. 
VaR 
 VaR is a statistical measurement of price risk. 
 VaR assumes a static portfolio. It does not take 
into account 
 The structural change in the portfolio that would 
contractually occur during the period.  
 Dynamic hedging of the portfolio 
 VaR calculation has two basic components 
 simulation of changes in market rates 
 calculation of resultant changes in the portfolio value. 
VaR (Value-at-Risk) is a measure of the risk in a portfolio 
over a (usually short) period of time. 
It is usually quoted in terms of a time horizon, and a 
confidence level. 
For example, the 10 day 95% VaR is the size of loss X that 
will not happen 95% of the time over the next 10 days. 
5% 
95% 
(Profit/Loss Distribution) 
X 
Value-at-Risk 
Standard Value-at-Risk Levels: 
Two standard VaR levels are 95% and 99%. 
When dealing with Gaussians, we have: 
mean 
95% is 1.645 standard deviations from the mean 
95% 
1.645o 
99% is 2.33 standard deviations from the mean 
99% 
2.33o 
Standard Value at Risk Assumptions: 
1) The percentage change (return) of assets is Gaussian: 
This comes from: 
Sdz Sdt dS   o    + =
dz dt
S
dS
o    + =
or 
So approximately: 
z t
S
S
A + A =
A
  o 
which is normal 
Standard Value at Risk Assumptions: 
2) The mean return  is zero: 
This comes from an order argument on:  z t
S
S
A + A =
A
  o 
The  mean is of order At. 
) ( ~ t O t   A A 
The standard deviation is of order square root of Dt. 
) ( ~
2 / 1
t O z   A A o
Time is measured in years, so the change in time is 
usually very small.  Hence the mean is negligible.  
z S S   A = A   o
VaR and Regulatory Capital 
  Regulators require banks to keep capital for market 
risk equal to the average of VaR estimates for past 60 
trading days using X=99 and N=10, times a 
multiplication factor. 
  (Usually the multiplication factor equals 3) 
 
Advantages of VaR 
 It captures an important aspect of risk 
  in a single number 
 It is easy to understand 
 It asks the simple question: How bad can things 
get?  
Daily Volatilities 
 In option pricing we express volatility as volatility 
per year 
 In VaR calculations we express volatility as 
volatility per day 
 
year year
year
day
  o o
o
o    ~  = = % 6 063 . 0
252
Daily Volatility continued 
 Strictly speaking we should define o
day
 as the 
standard deviation of the continuously compounded 
return in one day 
 In practice we assume that it is the standard deviation 
of the proportional change in one day 
IBM Example  
 We have a position worth $10 million in IBM 
shares 
 The volatility of IBM is 2% per day (about 32% 
per year) 
 We use N=10 and X=99 
IBM Example continued 
 The standard deviation of the change in the 
portfolio in 1 day is $200,000 
 The standard deviation of the change in 10 days is  
 
200 000 10 456 , $632, =
IBM Example continued 
 We assume that the expected change in the value of 
the portfolio is zero (This is OK for short time 
periods) 
 We assume that the change in the value of the 
portfolio is normally distributed 
 Since N(0.01)=-2.33, (i.e. Pr{Z<-2.33}=0.01) 
  the VaR is  
2 33 632 456 473621 . , $1, ,    =
AT&T Example 
 Consider a position of $5 million in AT&T 
 The daily volatility of AT&T is 1% (approx 16% 
per year) 
 The S.D per 10 days is 
 
 The VaR is 
 
 
50 000 10 144 , $158, =
158114 233 405 , . $368,    =
The change in the value of a portfolio: 
Let x
i
 be the dollar amount invested in asset i, and let r
i
 
be the return on asset i over the given period of time.  
= A
i
i i
r x P
Then the change in the value of a portfolio is: 
But, each r
i
 is Gaussian by assumption: 
i
i
i
i
z
S
S
r   A =
A
=   o
Hence, AP is Gaussian. 
) , 0 ( ~ x x N r x P
T T
E = A
where 
(
(
(
=
n
x
x
x   
1
|   |
T
rr E = E
(
(
(
=
n
r
r
r   
1
Example: 
Returns of IBM and AT&T have bivariate normal distribution 
with correlation of 0.7.  
Volatilities of daily returns are 2% for IBM and 1% for AT&T. 
$10 million of IBM 
$5 million of AT&T 
Consider a portfolio of: 
T AT IBM
T
r r r x P
&
5 10   + = = A
has daily variance: 
0565 . 0
5
10
01 . 0 ) 02 . 0 )( 01 . 0 ( 7 . 0
) 02 . 0 )( 01 . 0 ( 7 . 0 02 . 0
5
10
2
2
=
(
T
Then 
Example: 
T AT IBM
T
r r r x P
&
5 10   + = = A
has daily variance: 
0565 . 0
5
10
01 . 0 ) 02 . 0 )( 01 . 0 ( 7 . 0
) 02 . 0 )( 01 . 0 ( 7 . 0 02 . 0
5
10
2
2
=
(
T
Then 
Now, compute the 10 day 95% and 99% VaR: 
Since AP is Gaussian, 
95% VaR = (1.645)0.7516= 1.24 million  
99% VaR = (2.33)0.7516 = 1.75 million  
The variance for 10 days is 10 times the variance for a day: 
565 . 0 ) 0565 . 0 ( 10
2
10
  = =
days
o 7516 . 0
10
  =
days
o
VaR Measurement Steps based on EVT 
 Divide total time period into m blocks of equal 
size 
 Compute n daily losses for each block 
 Calculate maximum losses for each block 
 Estimate parameters of the Asymptotic 
distribution of Maximal loss 
 Choose the value of the probability of a maximal 
loss exceeding VaR 
 Compute the VaR 
Credit Risk Mitigation 
Credit Risk Mitigation 
 Recognition of wider range of mitigants 
 Subject to meeting minimum requirements 
 Applies to both Standardized and IRB Approaches 
 
Collateral Guarantees Credit Derivatives On-balance Sheet Netting
Credit Risk Mitigants
Collateral 
Simple Approach
(Standardized only)
Comprehensive Approach
Two Approaches
Collateral  
 Comprehensive Approach 
Haircuts
(H)
Weights
(W)
Coverage of residual risks through
Collateral  
Comprehensive Approach 
 H - should reflect the volatility of the collateral 
 
 w - should reflect legal uncertainty and other residual 
risks. 
Represents a floor for capital requirements 
Collateral Example 
 Rs1,000 loan to BBB  rated corporate 
 Rs. 800 collateralised by bond  
  issued by AAA rated bank 
 Residual maturity of both: 2 years 
 
 
 
Collateral Example 
Simple Approach 
 
 Collateralized claims receive the risk weight 
applicable to the collateral instrument, subject to a 
floor of 20% 
 Example: Rs1,000  Rs.800 = Rs.200 
 Rs.200 x 100% = Rs.200 
 Rs.800 x 20% = Rs.160 
 Risk Weighted Assets: Rs.200+Rs.160 = Rs.360 
Collateral Example Comprehensive 
Approach 
 C   = Current value of the collateral received (e.g. 
Rs.800) 
 H
E
 = Haircut appropriate to the exposure (e.g.= 6%) 
 H
C
 = Haircut appropriate for the collateral received  
  (e.g.= 4%) 
 C
A
 = Adjusted value of the collateral (e.g. Rs.770) 
 
 
 
770 .
06 . 04 . 1
800
1
Rs
Rs
H H
C
C
C E
A
  =
+ +
=
+ +
=
Collateral Example Comprehensive 
Approach 
 Calculation of risk weighted assets based on following 
formula: 
    r* x E = r x [E-(1-w) x C
A
] 
 
Collateral Example Comprehensive 
Approach 
 r*  = Risk weight of the position taking into      
account the risk reduction (e.g. 34.5%) 
 w
1
  = 0.15 
 r   = Risk weight of uncollateralized exposure 
     (e.g. 100%) 
 E  = Value of the uncollateralized exposure  
     (e.g. Rs1000) 
 Risk Weighted Assets 
  34.5% x Rs.1,000 = 100% x [Rs1,000 - (1-0.15) x Rs.770] 
= Rs.345  
 
Note: 1 Discussions ongoing with BIS re double counting of w factor with Operational Risk 
Collateral Example Comprehensive 
Approach 
 Risk Weighted Assets 
  34.5% x Rs.1,000 = 100% x [Rs.1,000 - (1-0.15) x Rs.770] = 
Rs.345  
 
06 . 0 04 . 0 1
800 .
770 .
+ +
= =
Rs
Rs C
A
Note: comprehensive Approach saves 
Collateral Example 
Simple and Comprehensive Approaches 
Approach  Risk Weighted 
Assets 
Capital 
Charge 
No Collateral  1000  80.0 
Simple   360  28.8 
Comprehensive  345  27.6 
 
Operational Risk 
 
Operational Risk 
 Definition: 
 Risk of direct or indirect loss resulting from inadequate or 
failed internal processes, people and systems of external events 
 Excludes Business Risk and Strategic Risk 
 Spectrum of approaches 
 Basic indicator - based on a single indicator 
 Standardized approach - divides banks activities into a number 
of standardized industry business lines 
 Internal measurement approach 
 Approximately 20% current capital charge 
CIBC Operational Risk Losses Types 
1.   Legal Liability:  
inludes client, employee and other third party  law suits 
 
2 .  Regulatory, Compliance and Taxation Penalties:   
fines, or the cost of any other penalties, such as license revocations and associated costs - excludes lost / 
forgone revenue. 
 
3 .  Loss of or Damage to Assets:  
reduction in value of the firms non-financial asset and property 
 
4 .  Client Restitution:   
includes  restitution payments (principal and/or interest) or other compensation to clients.   
 
5 .  Theft, Fraud and Unauthorized Activities: 
    includes rogue trading 
 
6.   Transaction Processing Risk: 
    includes failed or late settlement, wrong amount or wrong counterparty  
 
Operational Risk- Measurement 
 Step1- Input- assessment of all significant operational risks 
 Audit reports 
 Regulatory reports 
 Management reports 
 Step2-Risk assessment framework 
 Risk categories- internal dependencies-people, process and 
technology- and external dependencies 
 Connectivity and interdependence 
 Change,complexity,complacency 
 Net likelihood assessment 
 Severity assessment 
 Combining likelihood and severity  into an overall risk assessment 
 Defining cause and effect 
 Sample risk assessment report 
Operational Risk- Measurement 
 Step3-Review and validation 
 Step4-output 
Basic Indicator  Loss Distribution 
Rate 
Base 
Bank 
|
1
 
EI
1
 
LOB1 
|
2
 
EI
2
 
LOB2 
LOB3 
|
N
 
EI
N
 
LOBn 
Bank 
Expected 
Loss 
Loss 
Catastrophic 
Unexpected 
Loss 
 
Severe  
Unexpected 
 Loss 
Standardized  
Standardized  
Approach 
Loss Distribution  
Approach 
The Regulatory Approach:Four 
Increasingly Risk Sensitive Approaches 
  
  
  
Bank 
Internal Measurement Approach 
Rate
1
 
Base 
Rate
2
 
Base 
Base 
Rate
N
 
Base 
Risk Type 6 
Rate 1 
EI
1
 
LOB1 
Rate 2 
EI
2
 
LOB2 
Base 
LOB3 
Rate
N
 
EI
N
 
LOBn 
Risk Type 1 
Internal Measurement Approach 
  
  
  
  
  
  
 
 
Rate of progression between stages based on necessity and capability 
Risk Based/ less Regulatory Capital: 
Operational Risk -  
Basic Indicator Approach 
 
 Capital requirement = % of gross income 
 
 Gross income = Net interest income  
            +  
            Net non-interest income 
Note: o supplied by BIS (currently o = 30%) 
 
Proposed Operational Risk Capital Requirements 
  Reduced from 20% to 12% of a Banks Total Regulatory Capital 
Requirement (November, 2001) 
   
  Based on a Banks Choice of the: 
 
  (a)   Basic Indicator Approach which levies a single operational risk charge 
  for the entire bank 
         
          or 
 
  (b)   Standardized Approach which divides a banks eight lines of business, 
  each with its own operational risk charge 
     
          or 
 
  (c)  Advanced Management Approach which uses the banks own internal 
  models of operational risk measurement to assess a capital requirement 
 
Operational Risk -  
Standardized Approach 
 Banks activities are divided into standardized business 
lines. 
 Within each business line: 
 specific indicator reflecting size of activity in that area 
 Capital charge
i
 = 
i
 x exposure indicator
i
 
 Overall capital requirement =  
    sum of requirements for each business line 
 
Operational Risk -  
Standardized Approach 
Business Lines Exposure Indicator (EI) Capital
Factors
1
Corporate Finance Gross Income   |
1
Trading and Sales Gross Income (or VaR)   |
2
Retail Banking Annual Average Assets   |
3
Commercial Banking Annual Average Assets   |
4
Payment and
Settlement
Annual Settlement
Throughput
  |
5
Retail Brokerage Gross Income   |
6
Asset Management Total Funds under
Management
  |
7
Example 
Note:
 1
 Definition of exposure indicator and B
i
 will be supplied by BIS 
Operational Risk -  
Internal Measurement Approach 
 Based on the same business lines as standardized 
approach 
 Supervisor specifies an exposure indicator (EI) 
 Bank measures, based on internal loss data, 
 Parameter representing probability of loss event (PE) 
 Parameter representing loss given that event (LGE) 
 Supervisor supplies a factor (gamma) for each business 
line 
 
 
      Op Risk Capital (OpVaR) = EI
LOB 
x PE
LOB
 x LGE
LOB
 x 
industry
 x RPI
LOB 
 
         
          LR 
firm
  
 
EI    =  Exposure Index - e.g. no of  transactions * average value of transaction 
 
PE    =   Expected Probability of an operational risk event 
   (number of loss events / number of  transactions) 
 
LGE  =   Average Loss Rate  per event - average loss/ average value of transaction 
 
LR   =  Loss Rate ( PE x LGE)   
 
    =   Factor to convert the expected loss to unexpected loss  
       
RPI  =   Adjusts for the non-linear relationship between EI and OpVar 
         (RPI = Risk Profile Index) 
   
The Internal Measurement Approach 
 For a line of business and loss type  
Rate 
The Components of OP VaR 
e.g. VISA Per $100 transaction 
20% 
4% 
8% 
12% 
16% 
1.3  9 
 
 
 
 
 
 
 
 
Loss per $1 00Transaction 
0% 
30% 
40% 
50% 
60% 
70% 
+  = 
The Probability 
Distribution 
The Severity 
Distribution 
The Loss  
Distribution 
Expected 
Loss 
Loss 
Catastrophic 
Unexpected 
Loss 
 
Severe  
Unexpected 
 Loss 
Eg; on average 1.3 
transaction per 
1,000 (PE) are 
fraudulent 
 
 
Note: worst case 
          is 9 
Eg; on average 
70%  (LGE) of the 
value of the 
transaction have to 
be written off 
 
Note: worst case 
          is 100 
Eg; on average 9 
cents per $100 of 
transaction (LR)  
 
 
 
Note: worst case 
          is 52 
Loss per $1 00 Fraudulent Transaction  Number of  Unauthorized Transaction 
Example - Basic Indicator Approach 
OpVar
Gross Income $3 b
Basic Indicator Captial Factor o
$10 b 30%
Example - Standardized Approach 
Business Lines Indicator Capital
Factors (|)
1
OpVar
Corporate Finance $2.7 b  Gross Income 7% = $184 mm
Trading and Sales $1.5 mm  Gross Income 33% = $503 mm
Retail Banking $105 b  Annual Average Assets 1% = $1,185 mm
Commercial Banking $13 b  Annual Average Assets 0.4 % = $55 mm
Payment and Settlement
$6.25 b  Annual Settlement
Throughput
0.002% = $116 mm
Retail Brokerage $281 mm  Gross Income 10% = $28 mm
Asset Management $196 b  Total Funds under Mgmt 0.066% = $129 mm
Total = $2,200 mm
2
Note:  
1. |s not yet established by BIS 
2. Total across businesses does not allow for diversification effect 
Example - Internal Measurement Approach 
Business Line (LOB): Credit Derivatives 
Note:  
1. Loss on damage to assets not applicable to this LOB 
2. Assume full benefit of diversification within a LOB 
Exposure Indicator
(EI)
Risk
Type
Loss Type
1
Number Avg.
Rate
PE
(Basis
Points)
LGE Gamma
RPI OpVaR
1 Legal Liability 60 $32 mm 33 2.9% 43 1.3 $10.4 mm
2 Reg. Comp. / Tax
Fines or Penalties
378 $68 mm 5 0.8% 49 1.6 $8.5 mm
4 Client Restitution 60 $32 mm 33 0.3% 25 1.4 $0.7 mm
5 Theft/Fraud &
Unauthorized Activity
378 $68 mm 5 1.0% 27 1.6 $5.7 mm
6. Transaction Risk 378 $68 mm 5 2.7% 18 1.6 $10.5 mm
Total $35.8 mm
2
Implementation Roadmap 
Seven Steps 
 Gap Analysis 
 Detailed project plan 
 Information Management Infrastructure- creation 
of Risk Warehouse 
 Build the calculation engine and related analytics 
 Build the Internal Rating System 
 Test and Validate the Model 
 Get Regulators Approval  
 
 
References 
 Options,Futures, and Other Derivatives (5
th
 
Edition)  Hull, John. Prentice Hall 
 Risk Management- Crouchy Michel, Galai Dan 
and Mark Robert. McGraw Hill