Questions tagged [risk-models]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
0
votes
0answers
6 views

How to compute SRISK for an unbalanced dataset?

I'm writing a thesis about SRISK in the banking sector. My dataset goes from 2005 until 2020 and I'm going to use the following formula to compute the systemic risk SRISK=k⋅DEBT−(1−k)⋅EQUITY⋅(1−LRMES) ...
0
votes
0answers
25 views

Guidance requested to learn Credit and Market Risk Modeling [closed]

Please lead me to a repository of programs and lectures / notes or reading material on Market Risk modeling and credit risk modeling, stress testing, VAR modeling or similar topics. Thank you
-2
votes
2answers
48 views

What happens if my risk factor caught by statistical risk model using PCA turns out to be totally different from other PM's risk factor? [closed]

In order to explain systematic risk we use risk factors and I've learned that since they try to explain 'systematic' risk, risk factors are relatively well-known. However, what happens if the risk ...
2
votes
0answers
119 views

Is implied volatility really all that usefull?

I take implied volatility as the positive floating point number which lets the BS formula match an observed option price (assuming we have some useful interest rate, some underlying, etc). How useful ...
0
votes
1answer
34 views

Why factor return is estimated given factor exposure?

When using factor risk model, especially fundamental risk model, factor exposures are given and factor returns are estimated using regression method. However, I cannot intuitively understand why ...
0
votes
0answers
34 views

Implications of modeling operational risks without frequency distribution

When modeling operational risk, the Loss Distribution Approach (LDA) is widely used. Usually, we model the loss frequency distribution and the loss severity distribution and then aggregate both to ...
2
votes
0answers
60 views

Arrow Debreu Price vs Green's function

How is the Arrow Debreu Price related to Green's function at an intuitive level and how is this used in practice? Note Added 2021/02/01 I came across this in the Black Derman Toy model paper by Boyle, ...
2
votes
1answer
75 views

Downside deviation (semivariance) in m.v. portfolio optimization

Currently I am considering the downside deviation or semivariance in a m.v. optimization framework. For this specific measure of risk I have found in papers different formulae. The majority of them ...
2
votes
1answer
173 views

Mean Absolute Deviation in m.v. portfolio optimization

I just read some articles about $MAD$ as a measure of risk in finance. Is the following formulation a correct way to implement a $MAD$ portfolio optimization model which minimizes risk without ...
2
votes
0answers
106 views

Implied Gamma VS Implied Volatility

Reading this paper, I'm struggling to understand what the author is saying with paragraphs below (see pages 39-42): We define Implied Gamma ($\Gamma_{\operatorname{implied}}$) as the value of the ...
-1
votes
1answer
88 views

Capital Allocation, VaR, Expected Shortfall

Are there any serious drawbacks / weaknesses in the Euler allocation method, when used to allocate VaR capital (and potentially Expected Shortfall) to risk factors in a portfolio? I notice that ...
1
vote
1answer
51 views

Model Validation Aggregation Documentation (Binomial, Hosmer-Lemeshow, Tolerance) - Credit Risk et cetera

I came across some document that says for a PD (Probability of Default) model in order to assess its accuracy you need to first look at the Binomial Test, then the Hosmer-Lemeshow Chi-square test, ...
0
votes
1answer
41 views

I’m trying to construct a binomial model that uses 2 risky model - number of steps varied

So with this question I am unsure how to even do a binomial model with 2 risky assets never mind having n-steps. All the examples I’ve found are either not containing any risky assets or only have one....
1
vote
1answer
143 views

Code (Python or R) references for operational risk models (AMA/COM)

I have to build an operational risk model and to be compliant with Basell II and III regulations I thought of using AMA (Advanced measurement approach) or COM (change of measurement). We have no ...
0
votes
0answers
37 views

Concavity of Cumulative Accuracy Profile curve

I am writing my thesis for the default probability estimation in low default portfolios. One way to estimate the probability of default is from the Cumulative Accuracy Profile (CAP) curve (Marco Van ...
0
votes
0answers
65 views

Calibration of the Ho Lee model in Excel only based on historical treasury rates (3 months)

I would like to calibrate the Ho Lee model $dr_t=θ_tdt+σdW_t$ with $θ(t)= F_t(0,t)+σ^2$ in Excel based on a time series of 3-month treasury rates and then compare the real time series with that ...
0
votes
2answers
481 views

Do the weights of the exponentially weighted moving average (EWMA) have to sum to 1?

I am currently trying to calculate a volatility by using the EWMA model because it is said to yield better results than just using an equal weighted calculation approach. However I am a bit confused ...
3
votes
0answers
45 views

ESG risk factors

In the context of EU action on sustainable finance, the European Commission has initiated a series of regulations in order to achieve the goals of Paris Agreement on sustainability. One of those ...
0
votes
1answer
76 views

Ratios or combinations of risk measures

In finance, alternative risk measures such as value-at-risk (VaR) and GARCH are introduced as replacements to standard deviation volatility. Is there any application or value where several risk ...
0
votes
0answers
18 views

scenario-specific covariance matrices for minimum regret portolio allocation

I am trying to follow the paper here https://www.wiwi.uni-siegen.de/banken/dokumente/2._szenariobasierte_aa_englisch.pdf and implement the minimum regret approach. In particular, the decision under ...
2
votes
1answer
213 views

Open source projects to gain demonstrable experience in implementing modeling in C++

I have a mathematics background with a PhD in mathematics (not related to stochastic processors or financial mathematics) and have been in derivatives valuation for around 6 years. When applying for ...
3
votes
1answer
160 views

Why didn't stock markets drop in response to COVID-19 earlier, way before Feb 21 2020?

The S&P500 started to drop only on Feb 20 2020, and the Nikkei 225 and the FTSE 100 on Feb 21 2020. Yet as early as Jan 120, COVID-19 was reported in Hong Kong, South Korea, and Japan. Their ...
4
votes
1answer
105 views

How to model/price the risk of Covid-19 and other pandemics

How would you model and price the risk of Covid-19 pandemic? These large cost low probability events with very little history seems to pose a particular challenge when quantitatively modeling and ...
2
votes
2answers
112 views

Quantitative risk management for energy markets

I'm currently preparing an exam about energy markets. The knowledge of notions of quantitative risk management accounts for the 50% of the total exam. During my university education, though, I didn't ...
2
votes
0answers
45 views

Where could I find code to compute Potential Future Exposure

Ideally code in SAS, R, Python or Matlab for calculations involving counterparties holding positions in energy markets on multiple price curves, with a Monte-Carlo methodology or a simpified ...
2
votes
3answers
149 views

PD and LGD for ECL calculations needs to be time dependent?

I'm studying the implementation of an expected credit loss (ECL) model. I have encountered a complication. Do I need to calculate a probability of default (PD) and loss given default (LGD) with a time ...
0
votes
1answer
111 views

Demonstration of the Schweinler-Wigner Orthogonalization procedure

Can anyone give me a practical demonstration of the Schweinler-Wigner Orthogonalization procedure? The steps of performing it or possibly a code snippet. The Schweinler-Wigner Orthogonalization ...
2
votes
1answer
1k views

Absolute and Relative Value at Risk

Is it correct to calculate the VaR as 99% max between loss and profit. E.g. if 99% VaR on the loss side of the distribution is -100, and on the positive side of the distribution there is a value ...
2
votes
2answers
281 views

Stop-Loss strategies

Does anyone know some bibliography about the problems or limitations of using Stop-Loss strategies in a portfolio? Let me explain better: for example you can have a portfolio of 30 stocks from ...
1
vote
0answers
90 views

How to correctly simulate volatility shocks?

I am working on the comparison of different volatility timing/target strategies on portfolios starting from different conditions (data, asset classes, calculation of realized volatility, different ...
-1
votes
1answer
102 views

Backtesting a stock scoring model

I'm working on a simple stock scoring model consisiting of 3 factors: 1.market cap 2.liquidity of the stock 3.the value at risk we defined 3 intervals for each factor and we assigned the ...
2
votes
1answer
197 views

Portfolio Systematic Risk, Breaking it down into factor % contributions

I have a portfolio (p) of N equities, with let's say weights vector (m) at the start of the calculation period. Each equity has its own set of factors (like corresponding country, industry index, etc.)...
2
votes
0answers
52 views

Conceptual help - Machine Learning on finance data set [closed]

I am working on Anomaly detection model problem for a finance data set - set of gift card activation transactions. My team member suggested an idea that " First train the model with normal instances ...
1
vote
1answer
335 views

Barra model: why standardize the fundamental risk factors?

The two main types of risk factors included in the famous Barra model are called the "fundamental factors", and "industry factors," and the thing that I do not understand is why are only the former ...
0
votes
0answers
34 views

How to Risk and Return using Carhart 4 factor model

I have to calculate firm risk and return for a group of firms. I have firm CUSIPs. I also have access to CRSP data from WRDS. Can someone explain to me how I can use CRSP and data from Ken French’s ...
4
votes
1answer
193 views

Dominating credit risk modeling approaches for capital calculation in banks

In Basel/CRR (capital requirement regulation) there are various approaches for the estimation of capital requirements. For corporate exposures there is the Foundations IRB approach (F-IRBA, own ...
0
votes
1answer
88 views

Having only 2 Industry risk factors?

Is it possible to build a risk model that only has 2 industry risk factors? For example, if I wanted just Tobacco and Healthcare industries as risk factors can I do that? If I did that do I have to ...
0
votes
0answers
58 views

Factor Loading with multiple exposures?

How do I decompose portfolio exposures when assets may have exposure to a few of my risk factors? For instance I have some sector and state specific risk factors. If I have a bond with exposure to ...
0
votes
0answers
132 views

Barra Equity Risk Model Methodology

I am interested in learning about the Barra's Equity risk model methodology. When I google, this is the first file that comes up: http://www.alacra.com/alacra/help/barra_handbook_US.pdf However, it ...
4
votes
2answers
2k views

How to add Risks-Not-In-VaR (RNIV) to VaR under Basel III

I am trying to generate/prove the magnitude of the over-conservativeness of the regulatory VaR (internal models) under Basel III against what a more accurate VaR would be. However, I can't seem to ...
2
votes
1answer
756 views

rationale for maturity adjustment formula in basel IRB formula

For capital requirement, rwa is computed as a product of terms including a K (unexpected losses). (As shown is the summary from wikipedia : https://en.m.wikipedia.org/wiki/Advanced_IRB ) K is ...
1
vote
0answers
67 views

Regression model: short vs long history

There is a dilemma between choosing short history (1-2 years) and long history (5-10 years) for a regression model. Are there any resources that offer some findings on pros and cons of these two? From ...
4
votes
0answers
99 views

Why are thousand-ish-factor vendor risk models not extremely overfit and inaccurate?

Many vendor risk models have many hundreds, or even thousands of factors (many of which are highly correlated with each other). Underlying all these risk models is some sort of covariance matrix in ...
1
vote
0answers
66 views

Philosophy of Financial Risk [closed]

Do you think that there exists a framework on that you can build risk measures? What are the necessary and desirable properties of a risk measure? (necessary means compulsory and desirable means more ...
2
votes
0answers
397 views

Need to solve the stochastic differential equation of Vasicek Model

How to solve the stochastic differential equation of the Vasicek model for the analysis of credit risk? I search in the article "The Distribution of loan portfolio value" (Vasicek) but he doesn't ...
2
votes
3answers
313 views

How to estimate market based PD and LGD for small enterprises?

I am estimating CVA/DVA for derivatives... How to estimate PD and LGD (or RR) based on market data for the small enterprises, if there is no external rating for them and they don't have bonds or ...
1
vote
0answers
77 views

Markowitz models with uncertain returns

I am analyzing the Markowitz models with uncertain returns as follows: after calculating the expected returns and the covariances of 30 monthly historical series of 30 stocks, I resolve the Markowitz ...
1
vote
0answers
52 views

Does it make sense to subtract VaR from spot shocks?

I have a model to compute the Event Risk (in dollars) from a shock to the spot price of an asset. I also have the 10-day VaR PnL for the same assets returns. These two numbers are then aggregated to ...
0
votes
0answers
1k views

Full Revaluation vs Factor-based Model for risk management

I am looking for literature on comparison of these two approaches. It looks like many places are using some type of Factor-based Model (Barra, Axioma, Northfield, etc.) for risk management purposes. ...
2
votes
0answers
70 views

Hedging jump models with a infinite number of derivatives

First of all, I inform you that I am not a financial mathematician and have vague knowledge about an incomplete market. Stochastic volatility models are incomplete so derivatives cannot be ...