Questions tagged [risk-models]

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22
votes
3answers
5k views

What is the necessary level of Econometrics-Know-How for a quant

It seems quants increasingly use econometric models at work. As someone who has sold his soul to probability theory and stochastical analysis I would like to catch up. What are the econometric tools ...
22
votes
2answers
936 views

How do macro funds manage risk and model asset returns? Do they use factor models?

Some of the largest funds in the world are entirely macro-based: Soros, Brevan Howard, Bridgewater. They trade across asset classes, and seemingly with very concentrated allocations. What type of risk ...
20
votes
4answers
4k views

When should you build your own equity risk model?

Commercial risk models (e.g., Barra, Axioma, Barclays, Northfield) have evolved to a very high level of sophistication. However, all of these models attempt to solve a very broad set of problems. ...
20
votes
3answers
3k views

Cleansing covariance matrices via Random matrix theory

I am exploring de-noising and cleansing of covariance matrices via Random Matrix Theory. RMT is a competitor to shrinkage methods of covariance estimation. There are various methods expressed usually ...
18
votes
1answer
999 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 ...
17
votes
3answers
4k views

Is Conditional Value-at-Risk (CVaR) coherent?

When the risk is defined by a discrete random variable, is CVaR a coherent risk measure? I stick to the following definition of CVaR: $$ CVaR_\alpha(R) = \min_v \quad \left\{ v + \frac{1}{1-\alpha} \...
17
votes
1answer
595 views

performance of historical VaR parameters

An historical VaR measure is parameterized in terms of the confidence level and also number of periods. Specifically, the $\alpha$% T-period VaR is defined as the portfolio loss x in market value over ...
15
votes
3answers
6k views

Gamma vs. Volatility Risk

Original Question: What is the link between Gamma and the Volatility Risk? It leads me to ask: - What is the Volatility Risk definition and what are the good practices to measure it? Thinking about ...
14
votes
1answer
767 views

Has any research used Bayesian networks to estimate risk factor betas?

Is there any published research on estimating the beta of a security with respect to one or more risk factors via Bayesian networks? I'd like to see if this is a promising angle of research.
13
votes
12answers
137k views

How to calculate unsystematic risk?

We know that there are 2 types of risk which are systematic and unsystematic risk. Systematic risk can be estimate through the calculation of β in CAPM formula. But how can we estimate the ...
13
votes
2answers
3k views

Cluster analysis vs PCA for risk models?

I built risk models using cluster analysis in a previous life. Years ago I learned about principal component analysis and I've often wondered whether that would have been more appropriate. What are ...
12
votes
1answer
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 ...
12
votes
1answer
655 views

What weights should be used when adjusting a correlation matrix to be positive definite?

I have a correlation matrix $A$ for an equity market that is not positive definite. Higham (2002) proposes the Alternating Projections Method, minimising the weighted Frobenius norm $||A-X||_W$ where $...
11
votes
2answers
3k views

Links to the risk model methodologies of the major providers?

There is quite a bit of art in constructing an equity risk model. This paper summarizes some of the key decisions: choice of factors, horizon matching, cross-sectional vs. time-series method, and ...
9
votes
2answers
1k views

Hierarchical Risk Parity with allocation constraints?

In the really interesting paper by Marcos Lopez de Prado a variation of risk parity is applied whereby the underlying assets of the portfolio are first split in 'correlation clusters' and the ...
8
votes
4answers
2k views

What does it mean to modify the factor loadings of a credit risk model?

I came across an example where a well-known weakness of a credit risk model was dealt with by augmenting some of the existing risk factors via increased factor loadings. This made the the model more ...
8
votes
4answers
2k views

Multi Factor Credit Risk Models

I am working in the area of building credit risk models. Upto this point, the model I have been focused on using the Asymptotic Single Factor Model, more popularly known as Vasicek Single Factor Model....
8
votes
2answers
1k views

Quantitative Real Estate Investment Finance

I'm wondering if there is an application of quantitative finance to real estate investment? Specifically I'm wondering about models for pricing small neighborhoods (or even single houses) that take ...
7
votes
7answers
3k views

Recommendation for a book on CVA/Credit Risk and PD/LGD/EAD modeling?

I need suggestions for some good books on the following topics: Credit Value Adjustment (CVA) / Credit Risk Probability of Default / Loss-Given-Default / Exposure-At-Default modeling Any pointers on ...
7
votes
1answer
629 views

Is volatility for the next day forecastable? To any extent?

In a more general way: is there 1) a methodological approach to quantify the correctness of a model that produces a probability distribution for the, say, S&P 500 index return for the next ...
6
votes
2answers
558 views

Choice of prior as a shrinkage target in portfolio construction?

There's various research showing how priors such as the minimum variance portfolio turn out to be a surprisingly effective shrinkage target in portfolio construction. The sell point of these priors ...
6
votes
1answer
3k views

Performance Attribution : Annualizing alpha & factor return contributions

Let's say I have a factor model which I am using for Performance Attribution. I'd like to separate returns from alpha vs. returns from exposure to various risk factors. For each date, the factor ...
5
votes
1answer
631 views

Quantitative risk model for an open real estate mutual fund in Europe

How useful are quantitative techniques for the risk analysis/management of a open real estate fund? I am thinking about an approach for Europe (US and other markets are probably quite different - ...
5
votes
2answers
444 views

quantiative risk measure how they are implemented in R and their use

So far I have just theoretical knowledge of risk measure and never used them in application. Therefore I have some basic question how risk measures are used in reality and how they are implemented in ...
5
votes
1answer
950 views

Definition of risk factors for market risk scenario testing

I am doing a research for stress testing in market risk. The usual process I found out for scenario testing is: Define risk factors upon the portfolio Define the desired scenarios Vary the risk ...
4
votes
9answers
2k views

Why would there be a positive risk-free rate?

Most financial models include a risk-free rate or risk-free asset. Why should there be such thing as a positive risk-free rate? I dont see why an asset would provide a positive (real) return if it ...
4
votes
1answer
388 views

questions on VAR manipulation

The book of Financial Risk forecasting by Danielsson gives the following example about VAR manipulation. I have two questions: 1) If $0> VAR_1 > VAR_0$ , why the following figure plots it as $-...
4
votes
2answers
419 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 ...
4
votes
1answer
111 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 ...
4
votes
1answer
476 views

What structural model does Reuters use for default probability?

When using Reuters, for each listed company there is credit tab that shows relevant information in terms of credit default. There is also rating class as well as one year default probability. It is ...
4
votes
1answer
172 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 ...
4
votes
2answers
1k 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 ...
4
votes
1answer
77 views

Measuring interest rate sensitivity for illiquid private investments?

There seems to be surprisingly little literature on this topic. If you had a portfolio consisting of an unlisted illiquid private asset class (eg private real estate, direct infrastructure or private ...
4
votes
1answer
632 views

Basel II modelling vs Solvency II modelling?

How do the two modelling frameworks compare? I spent some time developing PD LGD and EAD models for banking portfolios... But I never did insurance modelling project which I suspect is based on ...
4
votes
1answer
2k views

Modelling VIX Futures for risk management

I would like to model VIX futures. The aim is not pricing but risk management. Thus I want to get risk measures like volatility right and be able to accurately calculate correlations when the VIX ...
4
votes
1answer
737 views

Long-term vs short-term strategies \ investing

Suppose most investors have very short investing horizons and use appropriate (for them) strategies, but investor X has a very long horizon. He would like to trade some advantages (early withdrawal ...
4
votes
1answer
673 views

Discrete time Ho lee model

This is my first question in this forum. I am stuck with my current testing the Ho Lee model. I am having difficulty computing the perturbation factor $\Delta$. The ho lee model should be completely ...
4
votes
1answer
449 views

What research exists regarding implementation of reverse stress testing?

I need to implement a reverse stress testing model (definition here) I have searched around and cannot find anything substantial on the topic. Does anyone know of any good papers/references ...
4
votes
0answers
88 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 ...
4
votes
0answers
9k views

credit risk - How to calculate the probability of default (private companies)?

Part of my master thesis I am working with a company. I have the project to use their financial database with all the financials data (7 years) of approximately 3’000 companies. They have their own ...
4
votes
0answers
168 views

Risk factors for 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 the main risk ...
4
votes
0answers
799 views

Help With Quant Modelling Software [closed]

Im a software developer (freelance) working in investment banking, and I'm looking to improve my CV by gaining a better understanding of the financial quant role and the software used by quants to ...
3
votes
2answers
2k views

Determining portfolio risk return in R given historical data for individual holdings?

Currently we compute portfolio risk and return via our own C# program. Historical data is stored in a SQL database. We want to compute the risk and return parameters - given a portfolio (i.e. not ...
3
votes
2answers
246 views

Reasoning behind multiple names for the equivalent risk measures AVaR/ETL/ES/CVaR

Doe's any one know the history behind, or background of the multiple naming conventions for the equivalent risk functions. Different quant authors prefer using different names, does any one know why? ...
3
votes
1answer
488 views

Can portfolio Value-at-Risk be calculated analytically for multivariate t-distributed returns?

It is widely known that VaR is generally not sub-additive in all but the most restrictive cases (typically when a Gaussian return distribution is assumed, which fails when it matters the most). ...
3
votes
2answers
594 views

How to get Multivariate Betas from an Estimated EWMA co variance Matrix?

I have a portfolio of 4 assets. I also have returns for 3 indices. I want to get the multivariate betas for these 4 assets-based on these assets. I only have the 7 x 7 covariance matrix estimated by a ...
3
votes
1answer
148 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 ...
3
votes
1answer
91 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 ...
3
votes
1answer
101 views

Want to understand the links and relationship between all the risk metrics?

For Example : if Risk weighted asset (RWA) increased or decreased this month, which other risk metrics could have influenced RWA to increase or decrease. Also in different situations like, upward ...
3
votes
1answer
105 views

Longevity risk modelling

What is Longevity risk, and how to model it under DC and DB pension plans? characters|characters|characters|characters|characters|