All Questions

13
votes
6answers
2k views

Why are options trades supposed to be delta-neutral?

I'm reading Natenberg's book, and he says that all options trades should be delta neutral. I understand that this prevents small changes in the underlying price from changing the price of the option, ...
13
votes
3answers
9k views

Correlation between prices or returns?

If you are interested in determining whether there is a correlation between the Federal Reserve Balance Sheet and PPI, would you calculate the correlation between values (prices) or period-to-period ...
10
votes
3answers
2k views

When does delta hedging result in more risk?

There's a question in an interview book saying "when can hedging an options position make you take on more risk?" The answer provided is that "Hedging can increase your risk if you are forced to both ...
10
votes
1answer
306 views

What approaches are there for stress testing a portfolio?

Wikipedia lists three of them: Extreme event: hypothesize the portfolio's return given the recurrence of a historical event. Current positions and risk exposures are combined with the historical ...
9
votes
4answers
4k views

What is a martingale?

What is a martingale and how it compares with a random walk in the context of the Efficient Market Hypothesis?
8
votes
2answers
2k views

Why do we use GARCH(1,1) to predict volatility?

What makes GARCH(1,1) so prevalent in modeling especially in academia? What does this model has that is significantly better than the others?
7
votes
2answers
2k views

What is the mean and the standard deviation for Geometric Ornstein-Uhlenbeck Process?

I am uncertain as to how to calculate the mean and variance of the following Geometric Ornstein-Uhlenbeck process. $$d X(t) = a ( L - X_t ) dt + V X_t dW_t$$ Is anyone able to calculate the mean ...
6
votes
1answer
668 views

What is exactly Euler's decomposition?

I have often seen the following statement in different paper: As $\sigma$ is homogeneous and of degree 1, we use Euler decomposition and write $\sigma(x)=\sum_{i=1}^n x_i \frac{\partial ...
6
votes
2answers
9k views

How to simulate stock prices with a Geometric Brownian Motion?

I want to simulate stock price paths with different stochastic processes. I started with the famous geometric brownian motion. I simulated the values with the following formula: ...
6
votes
1answer
986 views

A generic limit order book: What are the most important queries it should be able to answer?

Assume a class LimitOrderBook which represents a limit order book in a trading system. To be able to represent the limit order book a data handler reads a feed ...
5
votes
4answers
2k views

How to get greeks using Monte-Carlo for arbitrary option?

Let's assume I have an arbitrary option that I can price using Monte-Carlo simulation. What is the general approach (i.e. without relying on specific option type) to calculating the greeks in this ...
4
votes
1answer
9k views

How to interpret results of Johansen Test?

I have two time-series a & b. The objective is to find out whether two series are cointegrated or not. I am using Johansen Test in R to find this out. I am using urca package of R. Here is the ...
4
votes
7answers
1k views

Recommendation for a book on CVA/Credit Risk and PD/LGD/EAD modeling?

I need suggestions for some good books on the following topics: Credit Value Adjustment (CVA) / Credit Risk Probability of Default / Loss-Given-Default / Exposure-At-Default modeling Any pointers ...
4
votes
2answers
1k views

Mass Market Data Source

My current project requires large amounts of historical and real-time market data (1m or 5m bars for various products, mostly US futures for as far back as available). This data will be analyzed by ...
3
votes
3answers
2k views

How to detect and adjust for stock splits? [duplicate]

I am using a large daily data panel for over 250 companies and over several years. I am concerned about adjusting for stock splits. Is there any program in SAS to detect stock splits? How do I adjust ...
3
votes
3answers
1k views

How much capital do I need to create a competitive automated trading strategy?

I'm a relatively small investor, and I'm interested in building my own fully-automated quantitative trading strategy. I also read about dark pools, and how difficult it is to get good prices on ...
2
votes
3answers
1k views

How is historical data for forex collected or computed?

I'm looking at four sources of forex data, as compiled in the question, What data sources are available online? And I think I must be misunderstanding something, perhaps something fundamental, but I'm ...
1
vote
1answer
214 views

Pre-trade evaluation and risk assessment of option trading strategies (in market practice)

When a trader gets conclusion of the volatility is being underestimated (via volatility cone or some other technology), actually there are multiple ways for his trading. (Let's assume the underlying ...
17
votes
7answers
18k views

What's the difference between volatility and variance?

How do they differ in what they imply about an underlying's (or any variable's) movement?
12
votes
5answers
1k views

is beta of a portfolio always meaningful?

Consider the following strategies: a stat arb strategy with no overnight exposure, but significant market exposure intraday. a market timing model which is always long or short the market. etc is ...
10
votes
4answers
2k views

What is a “coherent” risk measure?

What is a coherent risk measure, and why do we care? Can you give a simple example of a coherent risk measure as opposed to a non-coherent one, and the problems that a coherent measure addresses in ...
10
votes
8answers
4k views

Why does implied volatility show an inverse relation with strike price when examining option chains?

When looking at option chains, I often notice that the (broker calculated) implied volatility has an inverse relation to the strike price. This seems true both for calls and puts. As a current ...
8
votes
4answers
682 views

Is this a common variation of sharpe ratio?

As an aside on his answer on another question Freddy said: Sharpe ratio is an often cited metric, though I do not like it too much because you are penalized for out-sized positive returns while ...
8
votes
3answers
2k views

How does volatility affect the price of binary options?

In theory, how should volatility affect the price of a binary option? A typical out the money option has more extrinsic value and therefore volatility plays a much more noticeable factor. Now let's ...
7
votes
4answers
903 views

What commercial financial libraries are available to outsource implementation risk?

During our daily jobs as quants, we tend to be willing to develop all the quantitative libraries ourselves. While I know that we need to develop specific algorithms which are the foundations of our ...
7
votes
3answers
1k views

Limit order book size

I am trying to write a highly optimised limit order book and I wondered what sort of size I can expect for: Range of limit prices Number of orders at each limit price I am developing custom ...
7
votes
1answer
330 views

How to reduce variance in a Cox-Ingersoll-Ross Monte Carlo simulation?

I am working out a numerical integral for option pricing in which I'm simulating an interest rate process using a Cox-Ingersoll-Ross process. Each step in my Monte Carlo generated path is a ...
7
votes
2answers
2k views

Are there comprehensive analyses of theta decay in weekly options?

Are there comprehensive analyses of how much theta a weekly options loses in a day, per day? I know what the shape of theta decay looks like, in theory, where the decay towards zero happens more ...
6
votes
4answers
828 views

Threshold calculation for buying a mean-reverting asset

I am trying to figure-out an optimal policy for buying a unit when its price follows a mean-reverting price process (Ornstein–Uhlenbeck), when I have a finite time deadline for buying the unit. I ...
6
votes
4answers
2k views

Analyzing tick data

What are some of the commonly used techniques to analyze tick data? I am looking at tick data to see how the quotes/ mid-price evolves due to certain events in the market. Since tick data is ...
6
votes
2answers
876 views

Comparing MVO with Resampled Efficient Frontier

My question: How can I compare the Resampled Frontier (REF) to the standard MVO frontier when I have been provided with $\mu$, $\Omega$, and don't have access to true future data to test real out of ...
6
votes
1answer
896 views

What are the steps to perform properly a risk factor analysis on a portfolio?

I have been asked to perform a factor analysis on a given portfolio, assume it's a Swiss portfolio in CHF. First step, I chose which factors I would like to see in my analysis. The first factors I ...
6
votes
2answers
2k views

How to extrapolate implied volatility for out of the money options?

Estimation of model-free implied volatility is highly dependent upon the extrapolation procedure for non-traded options at extreme out-of-the-money points. Jiang and Tian (2007) propose that the ...
6
votes
2answers
1k views

Why does this Co-integrated basket look too good to be true?

You need quantmod & tseries in R to run this: ...
5
votes
5answers
1k views

Is there a charting API which allows to replicate Bloomberg chart tool features?

I believe that most of us will agree that being able to compute values is only part of our job, as we would also like to be able to display them nicely in order to better understand or help ...
5
votes
1answer
1k views

Optimizing a portfolio of ETFs

I am aware of how to do mean-variance or minimum-variance portfolio optimization with constraints like weights must add to 1.0 no short sells max weight in any ticker using basic quadratic ...
5
votes
1answer
830 views

How to simulate correlated assets for illustrating portfolio diversification?

I have seen multiple instances where people try to explain the diversification effects of having assets with a certain level of correlation, especially in the "most diversified portfolio" literature. ...
5
votes
2answers
883 views

Recommendation for a library to calculate the local volatility surface?

I'd like a library to calculate the options local volatility surface, i.e. the options implied volatility surface for a collection of strikes and their bid/ask prices. Here are the libraries I've ...
5
votes
2answers
2k views

Quantmod: what's the difference between ROC(Cl(SPY)) and ClCl(SPY)

I feel like I'm missing something fundamental here, but I can't shake the feeling that these two series should be equivalent. /edit: there is also dailyReturn(Cl(SPY)). I've seen all 3 of these ...
4
votes
0answers
217 views

Optimization: Factor model versus asset-by-asset model

In portfolio management one often has to solve problems of the quadratic form $$ w^T \Sigma w + w^T c \rightarrow Min $$ with portfolio weights $w \in \mathbb{R}^N$ a constant $c \in \mathbb{R}^N$ and ...
4
votes
2answers
557 views

SKEW and VIX relations?

My question is about the CBOE published index VIX and SKEW. To start with, I consider working on the variance dynamics. I calibrate the market data (such as VIX and VIX futures) into the Heston ...
4
votes
1answer
420 views

Should cointegration be tested using close or adjusted close prices?

When doing cointegration tests should I use the adjusted close price or just close price for the time series? The dividend of each stock is on different dates and can cause jumps in the data.
2
votes
1answer
2k views

Drawdown calculation for strategies

I am developing a trading strategy for currencies. I am trying to find an indication for risk, something like Sharpe ratio or Sterling ration; for that, I thought of using the (maximum) drawdown ...
13
votes
2answers
845 views

Why isn't the Nelson-Siegel model arbitrage-free?

Assume $X_t$ is a multivariate Ornstein-Uhlenbeck process, i.e. $$dX_t=\sigma dB_t-AX_tdt$$ and the spot interest rate evolves by the following equation: $$r_t=a+b\cdot X_t.$$ After solving for $X_t$ ...
12
votes
1answer
265 views

Which interest rate model for which product

Given the multitude of existing interest rate models (ranging from simple to very complex) it would be interesting to know when the additional complexity actually makes sense. The models I have in ...
10
votes
2answers
360 views

How to “uncluster” a set of financial data?

I am attempting to evaluate and compare the profit factor of different "test runs" of a FOREX trading strategy. My problem is that, despite an average time between orders of 2hr+, some of these runs ...
10
votes
5answers
937 views

Monte carlo methods for vanilla european options and Ito's lemma.

I understand that by applying Ito's lemma to the following SDE $$dX=\mu\,X\,dt+\sigma\,X\,dW$$ one obtains a solution to the above SDE which is as follows: $${X}\left( t\right) =\mathrm{X}\left( ...
8
votes
1answer
599 views

Quantitative before/after or financial engineering studies of a bid or ask tax?

Has anyone in the quantitative finance or financial engineering community studied the effects of a bid or ask tax with actual or simulated data? If so, what were the quantitative results or ...
8
votes
2answers
553 views

What is a reasonable upper bound on the performance of a daily trading strategy?

I am backtesting an equity trading strategy which trades only once per day. Is there a general rule of thumb for the reasonable upper bound on the rate of return of such a strategy? For example, a ...
7
votes
2answers
2k views

Why using 3 months forward to hedge fx risk on a fund of funds portfolio?

In my previous job, a fund of funds, they used 3 months forward FX contracts (renewed every 3 months) to protect their portfolio against currency risk. If I do understand why forwards are useful for ...

15 30 50 per page