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

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Expected Shortfall alternative formulation

Define: $$q_\alpha(F_L)=F^{\leftarrow}(\alpha)=\inf\lbrace{x\in \mathbb{R}\mid F_L(x)\geq \alpha\rbrace}=VaR_\alpha(L)$$ I want to prove that: $$ES_\alpha = \frac{1}{1-\alpha}\mathbb{E}[\mathbb{1}_{...
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505 views

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
852 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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2answers
157 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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1answer
77 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
118 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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43 views

How to understand quadratic finance or practice of Value-at -Risk(VaR)

We define the following notions for a jointly normally distributed random vector $P=(P_1,...,P_n)$ with f the density function. $$\mu=\int_{-\infty}^{\infty}(x_i-\mu_i)f_i(x_i)dx_i$$ $$\sigma^2_{ij}=...
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118 views

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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160 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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758 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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4answers
3k 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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497 views

VaR Calculation - Covariance matrix is not positive semidefinite

This is a basic question. I have three assets, equally weighted, and all the mutual covariances are -1. Then, the covariance matrix looks like - ...
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2answers
175 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? ...
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1answer
69 views

Historical Scenario analysis for stress testing

I am doing historical scenario analysis in order to calculate stressed VAR for which I have taken 2007-2008 US crisis. I have two question in this regard:- 1) As we have to take prices for stocks ...
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1answer
83 views

What would be an alternative if the VaR model is not acceptable?

Assume we have a VaR model wich says : the lost should not exceed X for more 3 days and we come up with more days where the lost exceeded X, what is usually done for the VaR model ? Do we switch to ...
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1answer
1k views

How to interpret/use VaR and Standard Deviation?

The parametric VaR is defined as follows: $$VaR=Z_a*Vol$$ Is this the best way to interpret how much risk is being taken on for a particular asset? How does one interpret volatility on its own if ...
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1answer
63 views

What is the correlation of stock options?

I want to calculate the VaR of two correlated option positions, and I know the correlation between stock price returns. I want to separately calculate $Var_1$,$Var_2$ for option 1 and 2, and then use $...
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1answer
2k views

VaR for FX forwards

I am trying to figure out some of the commonly used approaches to deal with FX forwards (in a currency portfolio containing spots, forwards and swaps) that would allow me to calculate the one day VaR ...
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1answer
31 views

Historical VaR on Commodity Physical Forward

Recently came across building Histroical VaR for commodity forward position. Understood from quants guru the best way to calculate VaR is using full re-valuation, Full reval is computationally ...
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1answer
85 views

Monte Carlo VaR assuming logistic distribution

I have a Monte Carlo model which measures the Value at Risk (VaR) for given portfolio. I use the geometric brownian motion to model the prices. But let's say I assumed the returns of prices follow the ...
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1answer
75 views

Why normalize only data for CDSs for PCA?

I'm reading a Credit Suisse Research Report on PCA. The report says that to preprocess the data, you should "Centre data (and normalize when considering CDS data)." Why would you only normalize ...
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1answer
713 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
2k 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
3k 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 ...
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23 views

VAR FPCA analysis paper replication

I've been trying to replicate the following publication: toronto.edu/sjaimung/papers/VAR-FPCA.pdf but I havent been able to get the same results estimating the $\beta_{k}$ parameters. First, I got ...
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2answers
76 views

Parametric VaR of a portfolio including a swap

I am calcualting the parametric VaR of a portfolio that includes among other things an IRS swap that begins in the exact same day the valuation is done. Therefore, its NPV is 0 and I do not which ...
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24 views

Making apriori Statements on VaR Backtests with a Garch Modelled VaR

so I want to find out, if its possible to find out for any backtest for the Value at Risk(Kupics POF or Christophersen's Markov Test), if it is possible to make apriori Statements on Testing results ( ...
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1answer
125 views

Understanding the VaR example on wikipedia

In the wikipedia page on VaR The example says: ...
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425 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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3answers
65 views

What information should be delivered to the client so they have enough information to manage their exchange rate risks? [closed]

The client can be a CFO or CEO. The information can indicators, charts, graphs, statistics, ratios, etc. I know the VaR is one of them.
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151 views

Do people actually use VaR in professional settings?

VaR seems like such an obviously flawed metric, I am surprised that it seems to be used so much in the private sector. First, the way it is named and the way it is presented often imply it is the ...
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2answers
34 views

Value At Risk for Long and short position with same maturity and same traded price

I am not a quant geek.I always have doubt what should be the VaR output for portfolio contains long and short of the same maturity @ same traded price. e.g. CME corn future of sept expiry ...
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125 views

RiskMetrics VaR Volatility Sample Size

RiskMetrics calculates volatility using an exponentially weighted moving average. For a decay factor of 0.94, they advise a sample size of 74 past returns. Does this mean the entire calculation should ...
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67 views

Is it OK to consider the expected return is zero for stocks when calculating VaR over a short horizon?

I want to implement the approach described in the following recipe for calculating VaR: Is there a step-by-step guide for calculating portfolio VaR using monte carlo simulations I was told that I can ...
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329 views

How to compute the historical VaR for a portfolio with long and short positions?

I would like to calculate historical Value at Risk for a portfolio that includes both long and short positions in forward contracts. The part that confuses me is that I wonder whether the VaR of the ...
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661 views

Difference between VaR and credit VaR?

Quick question: is there a difference between credit VaR and VaR or are they the same thing?
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94 views

Variance covariance matrix for a portfolio containing bonds also with other asset classes

What should we take for a bond or a zero coupon bond in order to make a variance covariance matrix? For example:- Equities - we take the market price Cash - we take the spot rates Bonds - Do we take ...
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1answer
1k views

How to calculate Credit VaR?

(source John Hull, Options Futures and Other Derivatives 8th edition) I can't follow why Hull calculates Credit VaR in the following manner. I thought CVaR was Unexpected Loss$_{confidence}$ - ...
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1answer
381 views

Compute cross-gamma

I am trying to use delta-gamma method with montecarlo simulations to calculate the VAR of a portfolio consisting in options and equities. To use the method I need to compute a gamma matrix, that has ...
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3answers
404 views

Parametric/Analytical VaR

Suppose I want to calculate VaR for a known distribution with mean $\mu$, variance $\sigma^2$ and $\alpha$-quantile as, $VaR_{\alpha}$ = $\mu + \sigma q_{\alpha}$. For a Gaussian distribution it is ...
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98 views

Component VaR is additive but at what level

I have a portfolio data as ...
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249 views

How to backtest the VaR model?

I have a sorted historical P&L vector of 250 days and say, I want to calculate the 90% VaR on this distribution. I will look for the 225 element (90% * 250 = 225) and this will be my Value at Risk....
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1answer
36 views

PCA for stand alone equity VaR

I am trying to compute equity VaR, forex VaR and total VaR on an international portfolio (10 stocks x 4 countries). Since I am not interested in the risk disaggregation among diffrent countries I was ...
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28 views

Modelling nominal interest rates

What is the best model for nominal interest rates? ARMA, VAR, VEC, FAVAR, etc? I am a R user, so please advise me the most convenient R package to use as well. I intend to model US nominal interest ...
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22 views

help with p&L vectors historical simulation

My question is about the calculation of the Value at Risk based on historical simulation. I have a table which contains the P&L-vectors of each day of one year. But I don't know what is contained ...
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19 views

Value at Risk Backtest type 2 error

I am wondering why in the most popular tests(Kupiec's POF, Christoffersen, the Null hypothesis is "our model is accurate". If we set our null hypothesis that way, we only have a decent result if we ...
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41 views

Stress Testing of the portfolio containing Equities, Bonds and Options

I have a portfolio containing equities, bonds and options for which I have calculated VAR through variance covariance matrix. No I want to calculate the stressed VAR for which I have adopted the ...
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18 views

Monte Carlo - Inflated Asset Paths Due to Correlation

I built a MC generator for 12 assets based on Brownian Motion and noticed some strange results. Formula Used S(t) = Exp(S(t-1) + (mean - (vol. / 2)) + (stdev * Normal Distribution #)) S(0) = Ln(1) ...
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VaR mapping fixed-for-floating swap

I came across a problem that asks what risk factors to map a 5 year semi annual settle fixed-for-floating swap to given it's just before the reset date. Since a FRN prices to par just before the reset ...
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111 views

Delta Volatility Surface Usage to value the option

I always find myself in the unknown charted territory when it comes to non-Linear Instruments. I come across the scenario, How to value the option using Delta Vol surface? Example I have CME traded ...