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

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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: ...
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1answer
52 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). ...
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1answer
46 views

How to get around flat likelihood function when calibrating GBM parameters

(Hope this is the correct place for this question - I posted it first on stackoverflow:) I want to calibrate jointly the drift mu and volatility sigma of a geometric brownian motion, ...
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2answers
547 views

Volatility of a rolling window strategy

What methods can be applied to determine the volatility of strategy using a rolling window? Using normal standard deviation would bias the results as the returns will be highly correlated. Although, ...
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28 views

Correction factors for volatilities of smoothed returns

In An Introduction to High Frequency Finance (http://www.amazon.ca/Introduction-High-Frequency-Finance-Ramazan-Gen%C3%A7ay/dp/0122796713), the authors (on page 253) build a tick-frequency volatility ...
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42 views

Why volatility trading is touted as an institutional trade and not a retail trade

What is the reason that volatility trading is mostly touted as an institutional trade? And something unsuitable for retail traders? Do you need to have substantial capital, risk free rate of ...
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139 views
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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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1answer
47 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 ...
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2answers
78 views

Time-independent local volatility

Suppose somebody provides us with a surface of European call prices $C(\tau,K)$ where $\tau$ stands for time-to-maturity and $K$ for the strike. By Dupire's results, there is a unique local volatility ...
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36 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 ...
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2answers
87 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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7answers
21k 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?
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54 views

I have portfolio volatility for individual years, can I use them to compute portfolio volatiltiy for subperiods?

Thanks for opening this question. I have constructed some rules for a portfolio with annual rebalancing and am backtesting it for the period 1990-2014. I want to compare the risk-adjusted return to ...
2
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2answers
57 views

I have portfolio volatility for year 1 and for year 2. What is portfolio volatility for year 1 and 2 combined?

Thanks for looking into this question. Portfolio volatility in year 1 = 15%. Portfolio volatility in year 2 = 20%. What is the portfolio volatility over the timespan year 1 and 2 combined? Is it ...
2
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2answers
143 views

Is there a way to adjust R PerformanceAnalytics function VaR with EWMA or GARCH method?

Is there a way to upgrade R PerformanceAnalytics function VaR with more risk sensitive approaches like EWMA or GARCH? Or is there another R package which can handle the issue?
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0answers
54 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 ...
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39 views
2
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1answer
880 views

Historical volatility from close prices (Haug pg 166)

I have implemented a function for calculating historical volatility using close the close method as described by Haug on page 166. When I implemented the formula given by Haug, it resulted in some ...
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2answers
66 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 ...
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1answer
37 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.
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69 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 ...
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1answer
68 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 ...
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1answer
81 views

Which volatility to use to price options on futures contract?

I have some questions regarding pricing futures options and I just want to be sure that my thoughts are correct. I am trying to price options on futures for american & european style. In the ...
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0answers
55 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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3answers
290 views

What does it mean to be “long or short in volatility”?

I've heard a question regarding pricing of european calls. The question is: Is the call long or short in volatility when it is (deep) OTM? What is the profile of the implied volatility? I ...
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1answer
63 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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52 views

Volatility updating rule using r

I'm trying to program a volatility updating rule using iteration. I start with the well know Heston-Nandi model where the returns dynamics are : with is iid standard normal randome variable, where ...
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1answer
644 views

Risk Budgets with Target Portfolio Volatility

I'm working through the implementation of a risk budgeting approach as described in the recent Roncalli paper. The idea is that the portfolio manager sets a contribution of total portfolio volatility ...
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2answers
35 views

Comparing Portfolio Volatility with Index Volatility seems a wrong method?

thanks for looking into this question. I am comparing an investment strategy against the S&P 500 for a financial article I'm writing. I compute volatility of the Portfolio in this way, as the ...
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1answer
37 views

I have volatility of a portfolio in year 1 and in year 2. How do I calculate the volatility over the total 2-year period?

thanks for looking into this question. See the picture below (better is right-mousebutton - open in new tab). I also have the price and return data of the Stocks if that's needed to calculate the ...
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1answer
28 views

Transaction Costs Measure ATOP: What does it mean and exactly measure?

I went through some presentations about LowVol strategies for some indices. In the presentations were tables with average returns, vola, Sharp ratio and ATOP. I have no clue what this ATOP is supposed ...
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1answer
129 views

Some questions about implied volatilities and how to generate theoretical prices when market prices are not available

I am building a little Excel file that take some option prices in input and plots the volatility smile/surface. I have a script that reads market prices from the option chain for 3 different ...
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2answers
314 views

How to calculate the volatility matrix with multiple stocks

calculating the volatility for a single stock is straightforward. However, I'm not sure whether my approach for calculating the volatility matrix for multiple stocks is correct: I assume a log-normal ...
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3answers
831 views

Relationship between Beta and Standard Deviation

I was doing some financial analysis on two firms in the coffee industry. After calculating Beta and Standard Deviation for both firms, I seem to have stumbled on some weird phenomenon. It appears ...
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48 views

How do I track implied volatility of specific delta?

I'm a newbie with respects to volatility trading and options. I recently purchased a book on the topic called "Trading Implied Volatility -An introduction" by Simon Gleadall. It's been one of the most ...
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336 views

What good papers of short term (<30 seconds) volatility estimation [duplicate]

I am looking for good papers of short term (<30 sec) volatility estimation AND short term volatility forecasting. Do you have something in mind ?
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5answers
317 views

Can classical economics explain *any* of the so-called stylized facts of finance?

I am doing some reading on the (historical) emergence of the Black-Scholes implied volatility smile for index options (yes - post 87), and I stumbled across an economic paper attempting to explain the ...
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1answer
78 views

Arrow-Debreu Price in “The Volatility Smile and its implied Tree”

I was reading the old, but still interesting paper "The volatility smile and its implied tree" by Derman and Kani. I have a two questions about the derivation of the $2n+1$ equations, both of them ...
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1answer
287 views

How to Calculate Confidence Intervals for Moving Averages Given Nonindependence?

I've plotted 30-year moving averages across time for a couple of portfolios, and I was wondering how to calculate a 95% CI for the these moving average data (i.e., across all moving average data ...
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1answer
180 views

HAR-RV, realized GARCH and HEAVY model for realized volatility

I don't have much experience with volatility modeling using intraday data but I'm in the process of collecting 5mins data. Currently I have ~6 months of data. Is it enough to use these models with ...
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2answers
157 views

Does it make sense to use upward and downward volatility in option pricing?

Historically stocks have a higher likelihood to increase in price than to fall in price. As such would it make sense to split a stocks volatility measurement into upward and downward components? For ...
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93 views

Is the volatility for these two SDEs the same

$$ (1) \ \ d\left(\frac{1}{S_t}\right) =\frac{1}{S_t}\left(\sigma^2-r\right)dt +\frac{1}{S_t}\sigma dW_t $$ and $$ (2) \ \ dS_t = S_t rdt + \sigma S_t dW_t $$ How can you prove that?
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112 views

what volatility do we calculate using GARCH model

what volatility do we calculate using GARCH model, Historical vol or Implied vol or Future Vol or Actual vol.
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80 views

What math concepts are used in designing volatility models

What topics in statistics and mathematics do I need to understand thoroughly before I can start to dabble with stochastic volatility models and volatility arbitrage?
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34 views

volatility grouping

I was working on risk levels of a combined portolfio (includes options,futures as well as stock). While using greeks we can asses some value of a portolio, but when one needs to assess some kind of ...
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5answers
3k views

What are the advantages/disadvantages of these approaches to deal with volatility surface?

I would like to know if someone could provide a summarized view of the advantages and disadvantages of the approaches on the volatility surface issues, such as: Local vol Stochastic Vol ...
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50 views
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2answers
124 views

Is there a better way to price options than with historical volatility?

I know that annualized historical volatility calculated with closing prices is a much rougher estimate than implied volatility for the correct "volatility" parameter in options pricing models. ...
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1answer
40 views

Risk-free arbitrage given a volume oracle?

Given a magical oracle who can correctly predict the volume, but not the price, of a given security, does there exist a risk-free arbitrage to capitalize on this information?
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32 views

Normal vol - convention

apologies for the simplicity of the question, but I was wondering: what is the quoting convention for normal (bps) volatility? Say I have the following time series of data: Date Close Abs Change ...