# Questions tagged [variance]

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### Variance replication using options

I would like to understand the intuition behind the following question: Why a certain weighted sum of prices of put and calls is equivalent to the implied variance of an underlying? A variance swap ...
775 views

### Negative high frequency intraday volatility - Zhou estimator

To estimate high frequency tick data stock intraday volatility, I have read Robert Almgren's notes7.pdf http://www.cims.nyu.edu/~almgren/timeseries/notes7.pdf where he talks about the bias free ...
523 views

### out-of-sample variance using rolling window

I am currently working on the comparison of the constructed portfolios using out-of-sample variance criteria. I am going to use rolling window procedure for the comparison. First, I choose a window ...
611 views

### Geometric Variance

If the arithmetic mean is: $\frac { \Sigma (x_i) }{n}$ and the geometric mean is $(\prod (1+x_i) ) ^{1/n}$ The arithmetic variance is $\frac { \Sigma(x_i-\mu)^2 } {n}$ then what is the ...
190 views

### Variance Swap volatility

In an article, it is mentioned that a parameter is "the variance swap volatility at time t". I know what a variance swap is but I don't know what they could mean by "variance swap volatility". ...
2k views

### Variance swap replication and variance vega

Noob here. I've been trying to gain a better understanding of variance swaps and what better way than to replicate it with a portfolio of better understood instruments. I have read the GS 1999 ...
386 views

### What are the parameters of the function PORTVAR in Matlab?

According to the Matlab help, Portvar will give the "Variance for portfolio of assets" by entering the returns of the Assets and the corresponding weight. However, it does not explain the parameters ...
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### Why is this delta-hedging/P&L example on a variance swap call correct?

I'm looking into this article about var swaps: http://sbossu.com/docs/VarSwaps.pdf and not sure how to correctly interpret Exhibit 2.1.1. "In this example an option trader sold a 1-year call struck ...
113 views

### Variance calculation

How could I calculate variance when I have a snapshot of a portfolio that shows the following for each stock: Purchase Price, Close Price, Change in value, Change in percentage, Shares owned, ...
338 views

### how to compute daily skewness of S&P daily return timeseries under no other more high - frequency time series?

As we all know , return time series marked features: fat tail or negative skewness and peakedness. For a similar problem of variance computation, we can compute variance by garch model and other ...
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### Calculating Variance Explained from PCA Loadings

I have a return history for a universe of risky assets and I've run a principal component algorithm and obtained a loadings matrix (num_factors by num_assets) for the first 5 factors. I have a ...
1k views

### Calibrating Hull-White using volatility data

I would like to calibrate Hull-White model using volatility data.I am using [Park (2004)] paper as a reference. He suggests to minimize the following objective function: where the first term is ...
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### Do weights from portfolio theory contain bias?

I want to experiment with some portfolio modelling and I was wondering if you guys could help me with something. If I try to estimate and implement the traditional two-fund portfolio consisting of one ...
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### Linear regression and assets direction prediction

I have the following asset returns Y and the predictions for the same periods Y': Y = { 10, 200, -1000, -1, -7 } Y' = { 1, 2, -3, -4, -5 } The OLR R-squared for ...
545 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 ...
19k views

### Why would an investor trade a variance swap over a volatility swap?

Why would an investor trade a variance swap over a volatility swap? Is it simply related to the leverage involved in a Var (i.e. sigma-squared) or is there something else to it?
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### How to scale option pricing components in regard to time

I am looking at closed-form options approximations, in particular the Bjerksund-Stensland model. I have run into a very basic question. How should I scale the input variables in regard to time? My ...
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 ...
51k views

### What is the difference between volatility and variance?

How do volatility and variance differ in finance and what do both imply about the movement of an underlying?