# All Questions

1k views

### At what point does someone using technical analysis become a Quant?

Sorry if the question sounds rough. It's not my intention to devaluate something I've not yet understood like Quantitative Finance. So to keep it simple: is Quantitative Finance a science, like ...
278 views

### How to group timeseries showing similar curve

I am trying to classify similar looking curves of a timeseries and was wondering what is the best algorithm to research. Reading R, it looks like k-means clustering could be applied - but I don't know ...
1k views

### How do you evaluate a covariance forecast?

Suppose you have two sources of covariance forecasts on a fixed set of $n$ assets, method A and method B (you can think of them as black box forecasts, from two vendors, say), which are known to be ...
625 views

### Measuring liquidity

While liquidity is one of the key figure of financial markets, It seems to be very difficult to measure. Volume is sometime used as a proxy but can sometimes be completly irrelevant. Could you point ...
560 views

### Reference request: Survey article on GPU in Finance

I would like to get and idea of how people use GPUs in finance. I can find some specific papers or books on the subject. GPUs in binomial model, finite difference, monte carlo,... But I couldn't ...
685 views

### Rate interpolation in Libor Market Model

Libor Market Model (LMM) models the interest rate market by simulating a set of simply compounded, non-overlapping Libor rates which reset and mature on predefined dates. How do I obtain from them a ...
1k 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 ...
446 views

### Is it ever possible that---because of illiquidity---exercising an out-of-the-money option is better than directly buying the stock?

Is there a case, where due to illiquidity, exercising out-of-the-money options could be better than directly buying the stock? When a stock is too illiquid, there are some costs because of this ...
787 views

### What books should any quantitative portfolio manager or risk manager have as reference? [closed]

I'm interested to know what are the critical reference texts you rely on for portfolio or risk management? I mean those texts that you come back to because they are chock full of insight and know-how. ...
2k views

### How to combine multiple trading algorithms?

Is it possible to combine different algorithms so as to improve trading performance? In particular, I have read that social media sentiment tracking, digital signal processing and neural networks all ...
1k views

### Is there an all Java options-pricing library (preferably open source) besides jquantlib?

I am looking for an all-java implementation of black scholes, preferably open source. I found jquantlib and quantlib (C++). Any other recommendations? The jquantlib site seems to be down. I'd prefer ...
839 views

### How to conduct Monte Carlo simulations to test validity of Black Scholes for a specific option?

In reference to the original Black Scholes model, what approach is best to test the model in a rigorous way? Is there a standard approach that can accomplish this in a reasonable amount of time? ...
557 views

### Missing step in stock price movement equations

Assuming a naive stochastic process for modelling movements in stock prices we have: $dS = \mu S dt + \sigma S \sqrt{dt}$ where S = Stock Price, t = time, mu is a drift constant and sigma is a ...
505 views

### How to detect structural breaks in variance?

I'm looking for a method to automatically detect structural breaks, I tried Chow test, It works good but it doens't work for breaks in variance. Do you know a test to check strucutural break in ...
574 views

### How does one analyze diversification if stock prices follow a Cauchy distribution?

How does diversification actually lead to less variance in a portfolio? I'm looking for a formal reason why this is the case. There are a number of explanations I have been able to find, but they make ...
897 views

### George Soros models

Mr. Soros in his books talked about principles which are not used by today's financial mathematics — namely reflexivity of all actions on the market. Simply it can be given by following: ...
2k views

### What are the main limitations of Black Scholes?

Pls explain and discuss these limitations, and explain which models can I use to overcome these limitations. Alternatively, provide examples of how to modify the original Black Scholes to overcome ...
732 views

### How does UBS hedge its exposure to XVIX ETN?

I am wondering how UBS hedges its exposure to its ETN XVIX. Unless I am grossly overestimating the trading costs, executing the strategy they describe in their prospectus with futures would be quite ...
687 views

### Solving Path Integral Problem in Quantitative Finance using Computer

I've asked this question here at Physics SE, but I figured that some parts would be more appropriate to ask here. So I'm rephrasing the question again. We know that for option value calculation, path ...
557 views

### What is the expected return I should use for the momentum strategy in MV optimization framework?

As all research on the momentum strategies are focused on the indicator, i.e. the entry point, there seems not much discussion on its expected return? Though there are some discussions on the exit ...
587 views

### How to forecast expected volatility from high-frequency equity panel data?

I'm wading through the vast sea of literature on realized volatility estimation and expected volatility forecasting (see, e.g. Realized Volatility by Andersen and Benzoni, which cites 120 other ...
382 views

### Issues when considering a quantitative trading/finance firm

I have an upcoming quantitative trading interview (prop desk at a large bank), and I would like to have some good questions to ask about the group. However, I am changing fields from academia and I do ...
1k views

### How do I compare implied and historic volatility?

what would you suggest are the starting points for comparing, in an easy, visual way, implied and delivered volatility surfaces? I'd like to see what the differences are between the historic surfaces, ...
907 views

### What are some computational bottlenecks that quants face? [closed]

What are the current computational (non-network) bottlenecks now in a quant's workflow? What computational tasks would be revolutionary with a 10-100x improvement in performance using general purpose ...
294 views

### Enhancing Monte-Carlo convergence (crude method)

I am currently doing a project involving Monte-Carlo method. I wonder if there is papers dealing with a "learning" refinement method to enhance the MC-convergence, example : Objective : estimate of ...
1k views

### Is there a standard method for quantifying mean-reversion for use in directional trading?

Assuming a directional strategy (no pairs or spread trades) is there a "standard" method for quantifying mean-reversion? Should auto-correlation, variance ratios, hurst exponent, or some other measure ...
259 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 ...
735 views

### How to build a regime-switching model which knows its own limits?

In recent months I've come to the conclusion that there are not only certain regimes in the markets (like bear or bull) but phases where all models fail because we are in uncharted territory. The ...
779 views

### Where to find Greeks for futures to form delta-hedged futures portfolio of S&P 500 index/futures

I can't find S&P 500 index (SPX) futures data with Greeks to create delta-hedged portfolios. Do these data exist? I have access to most of the common data sources. In the meantime, I am trying to ...
3k views

### Cross Currency Swap Pricing in nowadays environment

Multicurve setting has now become the new paradigm for vanilla swap valuation. For the record I give here (without getting into too much details) the methodoloy for pricing Euribor3M swaps in this ...
303 views

### Model Validation Criteria

Let's say I have a brand new fancy model on some asset class (calibration porcedure included over a set of vanilla options) in which I truly believe I made a step forward comparing to existing ...
672 views

### Simulating Returns

I'll start this off with a rather broad question: I am trying to simulate returns of a large number of assets within a portfolio of different classes - equity and fixed income in a first step, say 100 ...
837 views

### Value-at-Risk of the sum of two dependent lognormal random variables

Hy I posted this question first at mathflow.net they suggested me this page, which I was not aware of. Question: Let $(X_1,X_2)$ be a multivariate normal random vector ($X_1$ and $X_2$ need not be ...
212 views

### How do you characterize dividends for equity options?

While many systems like to treat dividends as a continuous yield when pricing equity options, it works quite poorly for short-dated options. In the short run, deterministic dividends are clearly the ...
398 views

### Any recommendations for textbooks for an undergraduate course in mathematical finance? [closed]

I'll teach an introductory course on mathematical finance in the near future. The course is intended to entertain and broaden some well-prepared advanced undergrad mathematics majors, some physics ...
265 views

### Is Arithmetic Return Bias Basis of Low Vol Anomaly?

An observation in capital markets is that the connection between return and risk (measured as volatility) is not that straightforward (at least not as modern portfolio theory assumes). One interesting ...
341 views

### Exploiting breakdowns in correlation of estimated volatility

In the attached image I have a plot of the rolling correlation of 90-day historic volatility (using the Garman Klass estimator based on Sinclair's Volatility Trading) of JPM v. the S&P. As can be ...
306 views

### Creating an n-factor Certainty Equivalent Discounting Formula

Brealey & Myers provide a certainty-equivalent version of the present value rule, using CAPM, as follows: $$PV_0=\frac{C_1 - \lambda_m *cov(C_1, r_m)}{1 + r_f}$$ $PV_0$ - Present Value of cash ...
210 views

### What weights should be used when adjusting a correlation matrix to be positive definite?

I have a correlation matrix $A$ for an equity market that is not positive definite. Higham (2002) proposes the Alternating Projections Method, minimising the weighted Frobenius norm $||A-X||_W$ where ...
141 views

### A non parametric study of VaR with kernel density

I'm working in order to compare the calculation of the VaR between the methodology of copulas and kernel density, all this by using the software r. The process that I follow is: Obtain a sample ...
326 views

### Law of an integrated CIR Process as sum of Independent Random Variables

It is known (see for example Joshi-Chan "Fast and Accureate Long Stepping Simulation of the Heston SV Model" available at SSRN) that for a CIR process defined as : dY_t= \kappa(\theta -Y_t)dt+ ...
2k 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?
933 views

### When to shut down a trend following strategy?

Suppose I have trend following strategy(on close to close data) that is not getting acceptable returns for some time. When should I start thinking about shutting it down?
825 views

### How to optimally allocate capital among trading strategies?

I'm trying to find an optimal way to allocate capital among trading strategies. "Quantitative Trading" by Ernie Chan claims on page 97 that the optimal fraction of capital to allocate to a given ...
2k views

### How high of a Sharpe ratio is implausibly high for a low-frequency equity strategy?

I am looking to convince someone that an annualized Sharpe Ratio of 7 is 'extremely high' for a low frequency (daily rebalancing, say) long-short technical strategy on U.S. equities. I was hoping for ...
834 views

### How to generate a random price series with a specified range and correlation with an actual price?

I want to generate a mock price series. I want it to be within a certain range and have a defined correlation with the original price series. If I choose, say, oil, I want as many time series which ...
2k views

### What is the implied volatility skew?

I often hear people talking about the skew of the volatility surface, model, etc... but it appears to me that a clear standard definition is not unanimously in place among practitioners. So here is ...
683 views

### When hiring a quant, how can I protect my IP?

I am a one-man operation, and would like to hire a quant for around 4 weeks or work. I am worried that the person I hire might copy my data or the indicators that I have him work on. What have ...