# Questions tagged [risk-models]

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### 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 ...
1 vote
146 views

### Can PCA be used to transform a ladder of interest rate risk?

The context For traders/market makers on interest rate swaps desks, it is essential to have a model that transforms risk from its most complex representation (i.e. a ladder of every tenor) into a less ...
1 vote
113 views

### Calculation of Total Credit Risk Capital % but seeing lower capital percentage for higher risk band. Is there any correction required?

I am trying to calculate the Total Credit Risk capital % for my learning purpose as given below. Assuming adding 1 single loan with different pds. i have noticed one point in the table and have two ...
54 views

### equities hedging betas for a cross-sectional risk model

This question is on equities risk models. I would like to know how to define betas when using a cross-sectional regression approach, rather than the time series approach. My goal is beta hedging of a ...
36 views

### Probability Theory: Maximizing the difference between distribution functions

Given a sample of observations $X$, by changing a parameter $p$ we can divide $X$ into two subsamples $X_1$ and $X_2$ (this division is done in a non-trivial way which is nonetheless irrelevant to ...
188 views

### How do energy companies measure the magnitude of the risks of buying energy at a variable price and selling it at a fixed price?

Power and gas retailers are exposed to a variety of risks when selling to domestic customers. Many of these risks arise from the fact that customers are offered a fixed price, while the retailer must ...
511 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.)...
1 vote
1k views

### Why is the expected value of bias statistic one?

I have been reading about factor models recently. One of the ways in which the developer of these models (Barra/ Axioma) measure the accuracy of their models is by calculating the bias statistic for ...
59 views

### Simulating of short rate model

I'm trying to simulate the risk factor of PFE from the interest rate model. For example, under Vasicek model : $$dr_t = k(\theta-r_t)dt + {\sigma}dW_t$$ with the analytic solution, we can simulate N ...
98 views

### Risk mapping for Brazilian IPCA bonds [closed]

On Jorion's 'Value at Risk' chapter about risk mapping, interest rate swaps are decomposed in a portfolio of forward contracts so they can be mapped into risk factors. I'm trying to implement this for ...
1 vote
99 views

### Minimizing variance of a long short equity portfolio in practice

I understand the finance 101 explanation of how to minimize variance of a long-short portfolio using a covariance matrix. I also know that it doesn't really work because the covariance matrix is ...
1 vote
64 views

### Market risk factor proxies examples [closed]

I am reading some corporate documentation, including the notion of market risk factor proxy. Could you provide some examples of risk factors and their proxies? What I find obvious is the observable ON ...
414 views

### Filtered Historical Simulation VaR for swaps

I am trying to understand how to calculate FHS VaR for a portofolio of vanilla swaps. I think I understand the main ideas behind FHS VaR and how to implement it for other assets such as equities. I ...
1 vote
31 views

### Is "extreme CVaR" (CVaR from extreme value theory) elicitable or conditionally elicitable with some other statistical mapping (like VaR)? [closed]

I am not able to find loss function (scoring function) extreme CVaR (CVaR from extreme value theory) which is a conditionally elicitable statistical mapping (conditioned on VaR). In this regard, can ...
281 views

### Question on effective days of an exponentially weighted moving average model

I have been reading the book "RiskMetrics —Technical Document" by Longerstaey (J.P.Morgan) and Spencer (Reuters) (4th Edition, 1996). I am wondering what the effective days of the ...
75 views

### Aggregation of (cross-sectional) Factor model

Suppose I have a large factor model for security returns, i.e. I have a vector $\mathbf{Y}(t) \in \mathbb{R}^{P}$, with factor loadings $\mathbf{\beta} \in \mathbb{R}^{P \times K}$ over a set of $K$ ...
1 vote
109 views

### Modelling Specialised Lending deals

This question by itself is less a quant question but it has impact on the quantitative model to use. In 2006 CEBS gudilines we find a definition similar to this: Specialised Lending (SP) is a sub-...
1k views

### Models for measuring insurance risk exposure

I've recently begun working as a quant for a large bank, and one of my first tasks will be to improve the model determining the risk exposure of their insurance portfolio. The portfolio is fairly ...
662 views

### Marginal Risk Contribution under Factor structure

Given the factor structure below with K factors, the return for N assets is given by (under matrix notation): $R =\alpha + \beta F + \epsilon$ where $F$ is matrix of K factor returns and $\beta$ is ...
1k views

### Quantifying climate change risk

I am looking for resources on applicable and practical solutions for estimation and quantifying climate change risk from asset owners perspective (for example, a portfolio of equity, fixed income, and ...
1 vote
136 views

### How to test a risk model?

I'm reading the Barra risk model handbook (2004) available online and trying to understand the methodology. I've read a few materials on portfolio theory, so I can get at least the theoretical ideas ...
1 vote
99 views

### Techniques for proxying time series / stock prices

What are some good techniques for proxying time series? My purpose is for risk management / modelling and I would like proxy to missing series. Given that I also have to account for volatility, ...
117 views

### Introductory Books to Network Theory

Can anyone please suggest a good introductory book to Network Theory which is the area of mathematics that is widely used for systemic risk and contagion modeling in finance. If the book contains some ...
1k views

### Stochastic modelling of derivatives on dividends

I consider pricing and risk analysis of derivatives on dividends of the members of equity indices (such as Dow Jones EuroStoxx). There are options but I focus on futures. What are common stochastic ...
1 vote
48 views

### Core deposits forecasting in stress testing

I’m designing a stress test at a commercial bank. What are the advantages/disadvantages of forecasting core NMD deposits vs. total deposit balances?
1 vote
235 views

### Why does Hierarchical Risk Parity ignore the clusters generated?

I am currently working through the Hierarchical Risk Parity algorithm (Lopez de Prado (2016) link ) and trying to understand each of the steps. I have completed the step of creating the clusters, and ...
1 vote
365 views

### What is the market share of MSCI Barra Equity Model?

My understanding is that MSCI/Barra's model has a very large market share in funds and banks, but I cannot find out how large is the exact market share. Is there any data on this, or can someone ...
84 views

### are there any good papers on sector-specific versions of factor models?

Does anyone know of any good papers that build sector-specific (utilities, financials, energy, etc.) versions of factor models like the Fama French 3-factor or Carhart 4-factor models? For example, ...
111 views

### Practical implications of Andy Lo paper on Sharpe ratio using quarterly returns?

I am hoping to determine the practical implications of the Andy Lo paper criticizing the use of a scaling factor in converting periodic Sharpe ratio to annualized Sharpe ratio. I am particularly ...
108 views

### Ruin theory with infinite-mean Pareto-distributed claims: how to characterize the ruin time and the reserve prior to ruin

Consider the Cramér–Lundberg model $$\hspace{8em}R(t)=u+c\,t-\sum_{j=1}^{N(t)}V_{j}\,,\hspace{8em}(1)$$ where $c$ and $u$ are positive constants, $N(t)$ is a Poisson process with a rate $\lambda$ (in ...
161 views

### Market Risk FRTB - How to demonstrate that the linear transformation of the alternative definition of Vega reflects the actual vega risk?

I have a question regarding the use of alternative vega sensitivities (bank system sensitivities) in the context of the Vega Risk Charge of the SBM. The article 325t.6 of the CRR allows banks to ...
844 views

### Modelling callable bonds in a risk model (historical simulation)

What is a best-practice example on how to model callable bonds in a risk model - I focus on historical simulation (HS). For plain-vanilla bonds the input factors for historical simulation could be ...
61 views

### Variables for retail lending of bank

Typically to estimate the credit-worthiness of customers in retain bank lending, banks generally consider many demographic and socio-economic variables most importantly - Age, number of dependents, ...
109 views

### Standard market risk platform Value-at-Risk (VaR)

if possible, could you share publicly available methodological guides/pamphlets or post links to specialised websites which give sufficient detail of the basic assumptions, algorithms and possible ...
180 views

### Calculation of Expected Shortfall using IMA Approach ( FRTB)

I am trying to calculate the Expected shortfall of a FX portfolio through IMA Approach of FRTB in excel . I have used several combinations in excel to get the liquidity horizons and then calculate the ...
2k 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 ...
150 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 ...
148 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 ...
372 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 ...
104 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, ...
1k views

### Physical commodity trading quantitative risk return model

I am very new to commodities, I was previously in portfolio management/optimization (Black Litterman Markowitz etc). I am now a Buy-Sell analyst for Petrochemicals, and need to understand the basic ...
194 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 ...
2k views

### Portfolio risk analysis in Options & Mixed portfolios

I am currently working on a risk analysis model that is primarily focused on options portfolios, but will likely be later expanded to cover mixed (options, stocks, bond, futures, etc...) portfolios. ...
319 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 ...
191 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 ...
83 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 ...
1 vote
290 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, ...
91 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....