A measure of the degree of linear association between a pair of random variables.

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4
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2answers
264 views

Can we explain physical similarities between Black Scholes PDE and the Mass Balance PDE (e.g. Advection-Diffusion equation)?

Both the Black-Scholes PDE and the Mass/Material Balance PDE have similar mathematical form of the PDE which is evident from the fact that on change of variables from Black-Scholes PDE we derive the ...
4
votes
1answer
208 views

Is it possible to estimate the correlation between an equity and its IV, purely from its IV skew?

If we know the options Implied Volatility (IV) skew for an equity, is it possible to calculate the probability of the equity moving, given a move in the IV? We can define IV skew as the difference ...
4
votes
1answer
61 views

market change, correlation and estimation bias

I hear many quants sating that markets change very slowly. This "fact" is even presented as a justification of statistical arbitrage, for example, by affirming that correlations remain roughly the ...
4
votes
1answer
569 views

How to calculate implied volatility smile of basket using correlations?

For a basket, the realized volatility can be calculated using: $$\sqrt{\sigma_1^2 + \sigma_2^2 + 2 \sigma_1 \sigma_2 \rho}$$ If I have the volatility surface of two underlyings S1,S2 (strike space). ...
4
votes
1answer
108 views

tail correlation during crisis

I am seeking a recommendation for an empirical paper on increased correlations of returns during the 2008 financial crisis, or 'tail correlation' during the crisis, if that is different, or whatever ...
4
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0answers
172 views

Rolling window Kendall's tau against APARCH(1,1) correlation

Assume you want to forecast the correlation matrix of a stocks' basket (say 15 ~ 20 stocks from different sectors); assume you need to forecast at $T$ days because you will use the forecast ouput with ...
4
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0answers
245 views

Taking into account the correlation in Barrier options on a Basket

In a Barrier option (where the contract cancels when the underlying hits the barrier) I succesfully found the way to compute the probability of a single underlying touching the barrier (with constant ...
3
votes
1answer
74 views

What is the covariance of two correlated Ornstein-Uhlenbeck processes?

What is the covariance of two correlated Ornstein-Uhlenbeck processes? I was trying correlation(1,2)*Var1^(1/2)*Var2^(1/2), but I am not sure! I took ...
3
votes
2answers
386 views

correlation for portfolio of stocks

I have a portfolio of stocks and all I want to do is to make sure that I'm not trading one big position, so I would like to monitor some type of metric that gives me a rough idea of what the overall ...
3
votes
2answers
69 views

Bounded Stochastic discrete process

I just came across this stochastic process (link): $dY_t = (a-bY_t)dt + c \sqrt{Y_t(1-Y_t)}dW_t$, where $dW_t$ is a Wiener Process. According to the author under certain conditions this process is ...
3
votes
1answer
24 views

How to distinguish true negative eigenvalues from small negative eigenvalues due to floating point error?

Floating points have rounding errors so algorithm to find eigenvalues may report tiny negative eigenvalues but in reality thsee could actually be 0 if we had full precision. Any way to tell ? I have ...
3
votes
1answer
337 views

Rank Correlation Based Prediction

Are there any methods of prediction (machine learning, regression, etc.) which are designed to maximize the rank correlation (spearman correlation, kendall's tau, etc.) of your prediction with your ...
3
votes
1answer
98 views

volume-returns cross correlation interpretation

I want to find the relationship between volume and price returns in the S&P500. My first thought was to run a cross correlation in order to find who leads and who lags in the relation. It´s my ...
3
votes
2answers
137 views

Why can't I multiply two SDE Solutions?

SDE 1 is S1 = S10 exp( (r1-sigma^2/2) * dt + sigma dW1 ) S2 = S20 exp( (r2-sigma2^2/2) * dt + sigma2 dW2 ) E[dW1 dW2] = rho I want to price an option on S1 x S2 I know I need to use the SDE's to ...
3
votes
1answer
123 views

Partition assets into minimally correlated portfolios

My question covers a more or less classical portfolio optimization situation with a twist: How to partition assets into minimally correlated portfolios, with and without asset overlap. I have $N$ ...
3
votes
1answer
117 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 ...
3
votes
1answer
255 views

Does the correlation amongst stocks rise when stock values decline?

Is there any research on whether the correlations among stocks rise when stock indices decline? Which model could account and test for that effect ? Maybe GARCH-BEKK, or some models using copulas?
3
votes
3answers
663 views

portfolio diversification tester

Are there any online tools (optionally with developer API, to spare me the scraping) that given an existing portfolio, calculate how well a new candidate position would score to increase combined ...
3
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0answers
289 views

How to calculate correlations(COT report) in R ? [closed]

First thing i want to do is load data(.csv) into R. The data i am concentrating are the COT reports. Want to load a single column into R and calculate the correlation with the proper instrument.
2
votes
2answers
407 views

Why does it “say” portfolio diversification not suitable during market turmoil?

Currently I am trying to get a hold of MPT, asset allocation and related applications. While reading a particular resource, it says diversification works best for "normal" financial markets and ...
2
votes
2answers
111 views

What do you do with low r-squared when calculating high-frequency beta

I am calculating a high-frequency beta. For example I have 90 days of data of the S&P and GOOGLE and I have 10-minute percent returns for each instrument. Each day has 34 10-minute percent returns ...
2
votes
1answer
128 views

Correlation of asset to portfolio, given certain variables

Ultimately I'm trying to calculate stdev contribution, but I've hit a hurdle. What I have: 20x20 correlation matrix for various assets Standard deviations for each asset Returns for each asset ...
2
votes
1answer
109 views

How to account for correlation between strategies when they are added linearly?

There are n strategies which are going to be combined linearly. Using a pre-exisiting model I get a set of n weights which will be used to combine the strategies. But the model does not take ...
2
votes
2answers
4k views

Why do stocks with a negative beta return less than the risk free rate?

Let's say we have two stocks, Stock A and Stock B. Both of them have the same standard deviation $\sigma$, and therefore have the same risk. The only difference is that Stock A has a perfect ...
2
votes
2answers
2k views

Are two stocks with the same beta have a correlation of 1?

If two stocks have the same beta over same time period, does it mean they are 100% correlated over that time period? In a CAPM framework, a stock's beta is defined as $$\beta_1={\rm Cov} (R_1, M) / ...
2
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2answers
143 views

Buying one company or index against another, is this readily possible with options, with an accurate return (also Alpha Indexes)

There's a relatively new product in the market / on the Nasdaq called Alpha Indexes. It lets one own a company -- e.g. Apple, GE, Google, etc -- as the difference between how that company does (the ...
2
votes
2answers
62 views

Why do CFDs track the underlying?

My understanding of CFDs is that the profit you make on a CFD is the difference between the price at which you bought the CFD and the price at which you sold your CFD minus various charges/commission. ...
2
votes
2answers
185 views

2 stocks, no shorting vs shorting. (concrete questions, mean-variance)

I'd appreciate help with the following questions. Suppose there are two stocks $A$ and $B$ with expected returns $E_A, E_B >0$ and volatilities $v_A, v_B >0$, respectively . Also, suppose ...
2
votes
1answer
596 views

Need overlapping sample autocorrelation correction for calculating asset return correlations

I want to measure the covariance structure of various asset returns based on varying investment periods. Campbell and Viceira (2005) do this, using known return predictors (i.e. dividend yield, ...
2
votes
1answer
1k views

Counterintuitive time varying Beta with Kalman filter

If you're used to play with R, you'll enjoy the following reproducible code: ...
2
votes
1answer
99 views

Estimating correlation using EWMA

I am using an EWMA model to evaluate the correlation between yearly time series. I know Riskmetrics uses $\lambda=0.94$ for daily data and $\lambda=0.97$ for monthly data. Is there a value ...
2
votes
1answer
281 views

How to create a basket of currency pairs with the lowest correlation in R?

My strategy is designed to buy and sell all assets of a universe and rebalance periodically. It goes either long or short. To limit risk exposure to a single currency I would like the assets in the ...
2
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2answers
130 views

hedging correlated instruments

If two instruments have a significant negative correlation but the percent change in the price of the instrument moving in positive direction is always more by a fraction than the one moving in ...
2
votes
1answer
381 views

Analog - Pattern Recognition model using KNN

I'm building a pattern recognition model for my master thesis. The idea is to build a framework with some Macro variables (long/short term rates; rates differential; equity; fx; vix) in order to find ...
2
votes
2answers
75 views

Is this a reasonable approach to determine the relative importance of valuation factors?

I am trying to come up with a measure of relative importance of a number of valuation factors. I am wondering whether correlation coefficients can't be used for determining this. More on the issue: ...
2
votes
2answers
390 views

Correlated Wiener processes of different factors

I'm relatively new in this field, so I have a couple of points that I need to clarify. I would like to know how I can estimate the correlation matrix necessary to implement a Cholesky decomposition ...
2
votes
1answer
259 views

Combining covariances?

Consider an economy with assets with return processes $A$, $B$, $C$, $D$. Consider a weighted index with return process $I=aA + bB + cC + dD$ where $a,b,c,d$ are coefficients, and $a+b+c+d = 1$. ...
2
votes
2answers
712 views

How to calculate cumulative loss from two factors that have negative correlation?

I went through the most advanced books on statistics and still can't find an answer. There is a well known formula for combining volatility of two correlating variables, but what about adding the ...
2
votes
0answers
46 views

serial correlation, Fama MacBeth (1973) procedure incorporating momentum

I have a question regarding the use of the Fama-MacBeth (1973) procedure on panel data. I am investigating the cross sectional determinants of expected REIT return following the procedure from: Chui, ...
2
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0answers
29 views

In May of 2005, several large hedge funds had speculative positions in CDO tranches

These hedge funds were forced into bankruptcy. This was due to: the correct answer is: Long Mezzanine and Short Equity Tranche position when correlation of Mezzanine tranche decreased. Can anyone ...
2
votes
1answer
69 views

decompose correlation swap pnl

For a Variance swap we can split the pnl into a realized part and a "forward going" part. To be more precise: Assume we enter the trade at t0, and the variance swap has tenor T and a strike $Kvar$. ...
2
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0answers
72 views

Inflation/Rates Correlation

I've been looking into a short piece of maths a colleague has written on pricing inflation with payment delays, and was hoping someone could confirm whether my understanding is correct, or if my ...
2
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0answers
160 views

Correlation between idiosyncratic residuals and forward returns

The classic mean-reversion strategy is to calculate an "expected return" (alpha) by computing the raw return for each security and then remove the part which you think is market driven. Statistically ...
2
votes
0answers
190 views

Potential pitfalls in the use of correlation

Background: The red line is an index, which goes from 0 to 100, measuring uncertainty in the markets. The dark blue line is a price index, which has a lower bound at 0, and virtually no upper bound. ...
2
votes
1answer
102 views

Correlation Multiple Currencies

If i have a portfolio of stocks from different currencies and i want to generate a correlation matrix from the stocks, how is the correct procedure ? Imagine a portfolio which the base currency is ...
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vote
3answers
2k views

Calculate correlation between two sub portfolios and the combined portfolio

I have two sub portfolios (lets call them portfolio a & portfolio b - a portfolio is just a vector of weights that sum to 1) that combine to create a total portfolio. I also have a 2 x 2 ...
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2answers
96 views

Garch for covariance matrix?

I have seen plenty of literature about GARCH on estimation volatility. how about covariance? There are plenty of risk models depending on the covariance matrix. I guess we can assume the correlation ...
1
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1answer
438 views

Testing Significance of Correlation

Lets say I have the returns of two stocks(stock1 and stock2). Now without running a regression, I lag one of the variables, calculate the correlation between the two stocks and repeat this process as ...
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2answers
39 views

Correlation between asset A and Portfolio X (which contains A)

After a few hours trying to solve this I give up! I need help. I need to calculate the BETA of an asset with respect to a portfolio that contains this asset. I have the volatility and correlations ...
1
vote
1answer
674 views

Given a correlation martrix, calculate portfolio's correlation with its assets

Find correlation vector like $[ d e f ]$ where d, e and f represent correlation of P(portfolio) with its assets A, B and C respectively. The assets A, B, C can be another portfolio. In order for ...