Questions tagged [var]

Value at Risk, a widely used risk measure of the risk of loss on a specific portfolio of financial assets.

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What are the pros and cons of historial and Gaussian approaches to VaR?

What is the difference between historical and Gaussian method of VaR estimation? I know how they are calculated, but what are the pros and cons of each?
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665 views

Fixed Income VaR: Yield Vol vs Cash Flow Mapping

I have come across two ways of measuring VaR for Fixed Income instruments thus far: Express the volatility in of basis points and the position in terms of sensitivity to a 1 basis point movement in ...
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2answers
223 views

Futures Parameters for Value at Risk

I am new to risk management. I am calculating the VaR for a portfolio of futures contracts, long and shorts. I calculated it using the historical, parametric, and ...
3
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1answer
116 views

Value-at-Risk for a portfolio model with Gearing

My models: Say I want to construct a portfolio so I maximize my expected return while keeping my risk (measured by Value-at-Risk) lower than my risk target. $$\max \sum x_i \mu_i \\ VaR_{0.05} \leq \...
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1answer
126 views

Modelling operational risk for Basel pillar 2 (internal model for OpRisk VaR)

I am somewhat familiar with OpRisk for pillar 1. As far as I know OpRisk for pillar 1 will be replaced by standard approaches soon. So what is left is proper modelling in pillar 2. What are best ...
3
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1answer
135 views

How can I evaluate how poor a fit a parametric VaR result would be for a given holding?

I'm currently working on an application that, among other things, computes a one-day parametric VaR for security positions. I understand that the parametric method of computing VaR is a poor fit for ...
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45 views

Expected Shortfall for ARMA-GARCH Model

I need to find an analytical solution for the 99% confidence expected shortfall (CVaR) for a long position of 100 dollars at time $t$ for an asset with returns modeled by an ARMA(1,1)-GARCH(1,1) model ...
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79 views

Extreme Value Theory for Value-at-Risk: Advantage versus historical simulation?

I started researching this topic and it is well covered in the literature. My understanding is that it uses a historical time series of returns of a given set of stocks and represent such ...
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201 views

Parametric VaR of a portfolio of a stock and an option on that stock

I understand how to calculate the parametric VaR of a stock and an option separately. But I don't understand how one can calculate the VaR of a portfolio of a stock and an option on that stock using ...
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851 views

'GARCH - extreme value theory - copula' approach to estimate risk measures in R

I'm reading about this approach of using GARCH-EVT-copula methodology to separate univariate and joint estimation and then estimate for example VaR and ES. I wanted to try something similar, but my ...
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1answer
142 views

VaR calculation accuracy/comparison/effectiveness through different R packages

My question is what would be the better( in terms of estimation accuracy) method of VaR calculation among below two:, also any small code snippet will be great as a starting point for me. 1st method: ...
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27k views

Stressed Value at Risk vs Value at Risk

Just read some materials about SVaR. Is there only holding period that changes in comparison to VaR methodology?
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1k views

Covariance for arbitrarily large portfolios

I am implementing a method in Java to calculate the variance, covariance, and value at risk for a portfolio, which should be flexible for use with any number of assets in a portfolio. I am struggling ...
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3answers
340 views

Ran multivariate linear regression, checked normal probability plot, residuals are not normal. What can I do?

One of the required assumptions for multiple linear regression is that residuals are normally distributed, correct? After running my regression, my normal probability plot is showing the typical '...
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2answers
795 views

1 day VaR vs 10 day VaR

Even while using historical simulation VaR, 1 day VaR is converted into 10 day VaR by multiplying 1 day VaR by Sqrt(10) for regulatory reporting purposes. What are the underlying assumptions for ...
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4answers
2k views

Is Value At Risk additive?

I have computed the value at risk of 2 different commodities. Assuming they have not correlated, can I just sum the two standalone VaR to get my overall portfolio's VaR ?
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271 views

VaR estimate with Monte Carlo simlation

i want to verify the theoretical VaR 99% for the following Random Variable: \begin{align*} X=\epsilon + \nu, \end{align*} $\epsilon \sim \mathcal{N}(0,1)$, \begin{align*} \nu= \begin{cases}\begin{...
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1answer
145 views

Credit VaR Formula

in Chapter 23 of Hull's Options, Futures, and Derivatives he has an example (i.e. example 23.4) which shows how the Credit VaR formula is applied. The answer in the formula is 0.128. I can't seem to ...
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1answer
192 views

expected shortfall as unconditional expectation

Acerbi has several backtests for expected shortfall. The second backtest is based on this equality Does anybody know how to derive this equality? Can anybody explain, why it makes sense, especially ...
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471 views

Difference in Volatility Calculation from RiskMetrics 1996 to RiskMetrics 2006 VaR

In the original legacy RiskMetrics documentation from 1996, volatility is calculated using a simple exponentially weighted moving average with some decay factor to determine the weights. This would be ...
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1answer
4k views

Parametric VaR with Student-t distribution

Im using VaR to estimate parametric VaR. I have been able to do this using a Normal Distribution, however I want to also do this using a Student t-distribution and I'm unsure how to implement that in ...
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3answers
665 views

comparing modified VaR to ordinary VaR

What inferences can one draw when given a modified VaR at x% confidence and an ordinary VaR at x% confidence level. If the two are equal one inference can be that returns are gaussian but that also ...
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1answer
817 views

Value at Risk from Delta of a single asset portfolio

I am trying to figure out the following, for me unfamiliar type of question: Given is a single asset portfolio: the Delta of the portfolio is 15, the value of the asset is 10 and the daily volatility ...
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2answers
193 views

How to prove the following relation of Conditional Value-at-Risk and Value-at-Risk?

How to prove the following relation of Conditional Value-at-Risk $\text{CVaR}_{\alpha}(X)$ and Value-at-Risk $\text{VaR}_{\alpha}(X)$, \begin{equation} \text{CVaR}_{\alpha}(X) = \text{VaR}_{\alpha}(X)+...
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1answer
696 views

1-year Var calculated from 1 year volatility

I need to calculate Var with 1 year horizon. I think the correct way to do it is to calculate standard deviation of daily log returns, then calculate daily Var and multiply it by sqrt(250). But in ...
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2answers
3k views

VaR calculation methods of options

I am a little bit confused about VaR in Options and I need a clarification for. I collected the following formulas, can you suggest what is the best formula and explain me why, please?
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How to compute the VaR for European Call, using the delta-normal method?

I have a European call option with current stock price $S_0$, strike $K$, risk-free rate $r$, volatility $\sigma$, and time to maturity $T$ years. I assume that the stock price at time $t$, which is ...
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1answer
1k views

How to calculate VaR/CVaR for private equity, hedge fund, and alternative investment portfolios?

What is the best method for calculating VaR/CVaR for private equity, hedge fund, and alternative investment portfolios? I have only historical monthly return for them.
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1answer
38 views

Incremental/marginal contribution to VaR in a simulation setting

Estimating marginal contributions to VaR in a simulation setting is apparently quite difficult (see e.g. this blog post) due to issues with sampling variability. My question is whether the following ...
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1answer
1k views

EWMA VaR, code from Quant Risk

I am currently attempting to improve my python and understanding of VaR. I have been using the website Quant Risk: http://www.quantatrisk.com/2015/12/02/student-t-distributed-linear-value-at-risk/. ...
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1answer
276 views

Risk neutrality in the recent PRIIPs regulation

In the recent regulation (link pag 31 point 12) is reported the VaR according to Cornish Fisher. Is this a real world measure? By making computation I have seen that they assume an average return ...
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1answer
65 views

Free Data Sets for VaR calculations

I am trying to do some work on VaR and Expected Shortfall with the help of Generalized Pareto Distributions. Can someone please guide me to some dataset of financial data, preferably something like a ...
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1answer
695 views

VAR of portfolio containing options, equities and forwards

If we want to calculate VAR of a portfolio using variance covariance matrix (delta normal method), containing equities, forwards and options, how do we treat each asset class for making the variance ...
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1answer
84 views

Can you use a t-test on bootstrapped Value at Risk (VaR) figures?

I need to compare VaR before and after the recession. I have a series of market returns for a period before, and a series of market returns for the period immediately after. Both have been ...
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1answer
1k views

Elicitability of risk measures

I read that CVaR (Conditional Value-at-Risk, also Expected Shortfall), satisfies coherence, but not Elicitability. On the other hand, VaR satisfies Elicitability, but not coherence. What is ...
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1answer
7k views

Historical Value At Risk on option portfolio

I am new to Value at Risk subject in fact everything related to quant. Can any body validate the Value at Risk Model on the option price ? I am using a below explained approach . our portfolio ...
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1answer
2k views

Calculating the VaR from a GARCH(1,1) with Student-t innovations

I'm self-studying several questions on Ruey S. Tsay's teaching page. I'm experiencing some difficulty getting the correct answer for final exam 2013 Problem B Question 3. Given a Student-t GARCH (1,1)...
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1answer
126 views

Econometrics - Testing

If we have a time series of returns and two time series of indicators, how would we test the use of these indicators if they are autocorrelated or nonstationary (VAR Models dont produce significant ...
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1answer
5k views

What does this formula (to derive annualized volatility from VaR) mean?

I'm faced with the formula shown in the image below, which I just don't understand, in part because I've no grounding in stats, and in part because I don't even understand the notation: What's going ...
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51 views

Implied volatility surface modelling in filtered historical simulation

What is the best way to model implied volatility surface in filtered historical simulation (other than keeping it constant)? Is it appropriate to apply GARCH-like model to every point on the surface? ...
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1answer
184 views

Analytical portfolio optimization for VaR under multivariate normality

Given a set of assets with returns following a multivariate normal distribution with a known mean vector and a known covariance matrix, $$ r \sim N(\mu,\Sigma), $$ I want to find optimal portfolio ...
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296 views

RiskMetrics VAR calculations and conditional distribution of sum of log returns

According to Tsay's book in Chapter 7, for the Risk Metrics model: A nice property of such a special random-walk IGARCH model is that the conditional distribution of a multiperiod return is ...
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104 views

Modelling approaches for interest rate risk in the banking book (IRRBB)

I am having a hard time researching papers that deal with the measurement of market risk in the banking book. The trading book as I see it is similar to asset management and as the name says the ...
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55 views

VaR decomposition of non-normal portfolio by g-and-h distribution

According to Doowoo Nam (2013), VaR of non-normal portfolio returns approximated by g-and-h distribution can be decomposed pretty much in the same way as the VaR of a portfolio with normal returns. ...
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1answer
104 views

Can I split my backtesting into multiple consecutive sub-periods?

I'm testing a model to estimate the VaR of a portfolio with different stocks. I used 1500 data to estimate some parameters, and now I have other 1500 data for backtesting purposes (for a total of 3000 ...
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How to fit a VAR + GARCH in R

I should create a VAR model with Garch error in R but i don't know how to do it and which package to use. The Vector Autoregressive model (or VECM) should also have covariates in it. Then I should ...
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316 views

Testing Statistical Significance of Various Portfolio Simulations

I'm trying to determine which of my portfolio simulations/backtests if any are good enough to put some money into. I outline an approach below and I'm interested in knowing: What problems are there ...
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856 views

Fixed Income Var calculation

I'm trying to calculate var for a portfolio of fixed income securities. I initially want to just calculate undiversified VaR for each instrument. I'm doing the following for each instrument Take ...
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1answer
147 views

Energy Risk Quant--Any discussion boards for energy related quant topics?

Any discussion boards for energy related quant topics? Like VaR in energy portfolio, and pipeline option pricing.. just want to know where is the best discussion board for such energy specific topics. ...
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How to compute VaR of a simple equity portfolio?

How do I compute VaR of a simple equity portfolio? I know current weights and can easily access the history of the stocks' daily returns.