A measure of the variation in price over time. Also a measure of the risk of a financial instrument.

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81 views

Implied volatility and nonconstant volatility

John Hull states in his text that "AS the maturity of the option is increases the percentage impact of nonconstant volatility on (option) prices becomes more pronounced, but its percentage impact on ...
4
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1answer
99 views

volatility factor

I am trying to add a volatility factor to Fama-French factor model. Does anybody know of a source where I can get data for "volatility mimicking factor" or suggest a simple methodology for ...
4
votes
1answer
127 views

Options on Volatility Control Index

I have two question. Does an option on volatility control index exist? If I google it, it seems like there is such an option, but I can't find the option on any of exchanges. So this is my first ...
21
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2answers
2k views

Have Goldman Sachs Quantitative Strategies Research Notes been published as a book or a comprehensive collection?

Back in the 90's, Goldman Sachs (publicly?) released a series called "Quantitative Strategies Research Notes" — mostly technical papers on topic. Emanuel Derman co-authored almost all of them. Some ...
2
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1answer
112 views

How to use calibrated Standard Stochastic Volatility?

I'm considering the standard stochastic volatility model: $$x_t = \rho x_{t-1} + \sigma \epsilon_x$$ $$y_t = \beta \exp\left[ \frac{x_t}{2} \right] \epsilon_y$$ where $y_t$ is the log-returns and ...
2
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2answers
68 views

Measuring Volatility from Execution Prices

I was told of a way of measuring the volatility of a stock by looking at the reported execution prices (from Level III or Level II data.) I'm well aware of how to measure volatility by looking at the ...
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1answer
74 views

FX Portfolio Volatility Targeting

If I have 3 different currency trades (ex short EURSEK, short NZDUSD, long USDJPY), how do I size each trade if I wish to allocate risk equally in order to target a 12% portfolio volatility (allowing ...
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1answer
150 views

Looking for a definition of financial entropy

In Science, Entropy is generally considered to be the irreversibility of stuff. Google defines entropy as: lack of order or predictability; gradual decline into disorder The 'gradual decline in ...
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0answers
26 views

Return volatility or Price Volatility [duplicate]

Which is a better method to calculate volatility - Price variance or return variace or is it subjective to the use of volatility figure?
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1answer
115 views

Constant decreasing volatility, GARCH forecasting

I am trying to forecast the volatility using GARCH modelling in R. I fit an ARMA(1,1)-GARCH(1,1) model, but my sigma predictions are constantly decreasing. Anybody know why? ...
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2answers
94 views

Uses of Volatility models

I'm reading about volatility analysis here http://vlab.stern.nyu.edu/doc?topic=mdls. There are many variations of GARCH. My question is: rather than trial-and-error approach, is there any systematic ...
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0answers
51 views

Realized Volatility: errors correlation

When using Realized Volatility (sum of squared intraday returns) to estimate volatility, following the model: $$r_t = \sigma_t \epsilon_t $$ where $\sigma^2_t$ is the volatility at time $t$ and ...
2
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1answer
137 views

Effect of volatility on the delta of a call option

In the book 'Dynamic Hedging', Nassim Taleb writes: ...
2
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0answers
56 views

How to compute/find the volatility of an index like the S&P 500 to be used to control risk exposure? [closed]

I've asked two related questions. First this one on the money stack exchange and this one on the math stack exchange. But have not yet found a complete answer. Given an index such as the S&P ...
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0answers
53 views

Relation between Parkinson number and historical volatility

In his book 'Dynamic Hedging', Nassim Taleb gives the relation: P = 1.67*historical volatility, where P is the Parkinson number. What is the basis of this relationship. Does this hold under special ...
3
votes
0answers
98 views

How can a beginner trader make use of 'volatility of volatility'

For a beginner option trader in equity options, how can he use this metric that is provided by his broker/data vendor? How can he use this metric to gain an added understanding of the option ...
6
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1answer
243 views

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 ...
2
votes
1answer
217 views

Mean reversion time estimation

I am new to mean reversion trading, and I would like to get some good references about how to estimate the time it takes to a mean reverting process to cross its long term mean.
0
votes
1answer
60 views

Portfolio volatility

Problem True or fale? The stock of a firm has an expected return of 10%, and a volatility of 10%. The weight of the stock in a portfolio is 5%, and the correlation of the stock’s return with the ...
4
votes
3answers
367 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 ...
2
votes
1answer
221 views

High frequency price forecast model ARMA GARCH or another?

Can you reccomend model for high frequency data (1 second and less) (returns and volatility forecasting)? Most papers use ARMA, GARCH etc in 1 minute and lower time frame. PROBLEM ARMA does not know ...
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vote
2answers
185 views

A good way to calculate the realised daily volatility

Currently, I am confused about the calculation of realised daily volatility. Assume I have daily returns, for example, FTSE, then I need to estimate the daily realised volatility. I read some ...
0
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1answer
79 views

Volume or Volatility?

I've recently been given a project which came with some documentation. In this documentation is a bullet point that reads: Liquidity Risk in Equity, Credit and Vol I'm unsure as to whether vol is ...
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0answers
73 views

Cointegration and variance of time series

Given that $X_t , Y_t$ are two cointegrated random processes, what can we say about the relationship between variance of the two increments $var(X_{t+h}-X_t)$ , $var(Y_{t+h}-Y_t)$ for a given ...
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2answers
88 views

Short Volatility [closed]

Being net short options is an obvious case of being short volatility. But what other investments are "functionally" short volatility? Is long equities long or short volatility? Is short Apple long or ...
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vote
3answers
135 views

Direct use of implied volatility

I am not sure to understand exactly the direct use of implied volatility. Let's take an example: if an instrument has a daily volatility of $\sigma$, there is a 68% probability that its value will be ...
4
votes
1answer
462 views

Moving window forecasting in Python

I am looking to create some code that will out-of-sample forecast the HAR-RV model. The model itself is formulated as the following, and the betas are estimated through HAC-OLS or Newey-West. ...
2
votes
1answer
63 views

Solving a Non-Linear PDE using a Finite Difference Scheme

I have the following non-linear PDE and I have no idea how to go about solving it using a finite difference scheme in Python. Can someone get me started and/or point me to an algorithm for doing this? ...
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0answers
102 views

variance ratio for pair-trading

I am using the variance ratio test to check whether my sequence is mean reverting in that test there is a parameter n, How in general I choose this n? or what is the meaning of this parameter? ...
2
votes
0answers
81 views

How to calibrate volatility surface for Interest Rate Cap&Floor pricing

I'm using Black model to do interest rate Cap & Floor pricing. The volatility is determined by using the bootstrapping methodology. However, afterwards, how should I do the calibration, or ...
2
votes
1answer
165 views

On an application of Ito's lemma

Assume that instantaneous returns are generated by the continuous time martingale: $$dp_t = \sigma_t dW_t$$ where $W_t$ denotes a standard Weiner process and One day returns are denoted by $r_{t+1} ...
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0answers
53 views

Hedge volatility decreases

My particular options positions are typically a long delta, and long vega. Decreases in implied volatility, or specifically the VIX, can drastically alter the profitability of my position. Is there a ...
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2answers
93 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 ...
5
votes
1answer
148 views

DCC GARCH - Specificating of ARCH and GARCH parameter Matrices STATA

The command in STATA to calculate the DCC model of two variables is: mgarch dcc ( x1 x2=, noconstant) , arch(1) garch(1) distribution(t) $$ \begin{bmatrix} ...
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1answer
71 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". ...
2
votes
1answer
452 views

using garch to forecast volatility but getting low persistence model

I am using a GARCH(1, 1) model to try model volatility for a certain stock. I have a GARCH function in matlab that returns the three parameters, omega, alpha & beta. I then use this parameters ...
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2answers
159 views

How to write a home task report which is part of the interview process for a quant position in a trading firm

I recently appeared in an interview for a quant research post in a trading company. As part of the interview, I was given a home-task to solve in a week. The inerviewer gave me a dataset consisting of ...
1
vote
1answer
167 views

What is an appropriate algorithm to use for tax loss harvesting?

I've been reading into how Betterment and Wealthfront have architected their tax loss harvesting algorithms, but they stop short of providing any real examples. Essentially, they both reduce to: ...
4
votes
1answer
557 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
134 views

Question about historical volatility ranking

I have seen this strategy example, which uses garch in a regime switching context: https://systematicinvestor.wordpress.com/2012/01/06/trading-using-garch-volatility-forecast/ The author classifies ...
11
votes
1answer
3k views

Correctly applying GARCH in Python

Problem: Correct usage of GARCH(1,1) Aim of research: Forecasting volatility/variance. Tools used: Python Instrument: SPX (specifically adjusted close prices) Reference material: On Estimation of ...
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0answers
37 views

Reputational Harm

How would you measure the reputational harm incurred on an individual by an organization. How is Market Pricing in the expected payout resulting from the law suit by an individual ? The news breaks ...
6
votes
3answers
422 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 ...
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vote
0answers
136 views

How to hedge a long stock with the corresponding volatility ETF

Let us say I want to establish a market neutral position. So if I buy 50 shares of stock (SPY) and I want to delta hedge, I sell an ATM covered call. So that brings the position delta to 0. Now, I ...
3
votes
2answers
180 views

How to get around flat likelihood function when calibrating GBM parameters?

I want to calibrate jointly the drift mu and volatility sigma of a geometric brownian motion, $$\log(S_t) = \log(S_{t-1}) + (\mu - 0.5*\sigma^2) \Delta t + \sigma*\sqrt{\Delta t}*Z_t$$ where $Z_t$ ...
1
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1answer
109 views

European vanilla call/put option, when volatility increases, how will gamma changes?

according to the BS formula, $\gamma = \frac{N'(d_1)}{S_0\sigma\sqrt{T}}$, gamma will decrease when volatility increase. How does it intuitively make sense? rather than from the formula.
3
votes
0answers
223 views

Constructing Volatility Smile from American Options

My question is about best practices for reconstructing volatility smiles for a fixed tenor from American option data. For simplicity/liquidity, I am currently considering options on SPY. I am ...
1
vote
1answer
724 views

Bloomberg equity option volatility data

Using the Bloomberg open API, I am trying to program a C++ script that is able to download option volatility data from Bloomberg. I currently do not have access to Bloomberg, but in the coming week I ...
2
votes
1answer
138 views

Volatility Surface Constituents, do's and dont's

Recently I have been working a lot with implied volatility and volatility surfaces. The basic idea is easy to follow: 1) Gather market prices of options at different (Strike,Expiry) 2) Calculate ...
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2answers
427 views

Why is the vega of an at the money option so insensitive to movements in volatility? I.e, why do ATM options have such little Vomma?

I've been trying to understand why at the money options have very little vomma. I was reading and came across a graph that showed vega as volatility changes and I couldn't grasp how the relationships ...