15
votes
3answers
3k views

Why hold options when you can dynamically replicate their payoff?

When holding vanilla options, you can cancel out, theoretically, all risk with dynamic (delta) hedging. Then you earn the "risk free rate of return". Why would you make such a portfolio when you can ...
15
votes
2answers
1k views

From a high frequency point of view, with a price prediction and assuming infinite leverage, how do you determine optimal trade size?

I have read about something like Kelly criterion for long term expectation maximization assuming a fixed starting bankroll. But if one can assume unlimited leverage, and one has a signal for a price ...
15
votes
3answers
2k views

Is there any theoretical basis for pattern-recognition strategies?

Mean-reversion and trend-following strategies have some kind of a theory behind them that explains why they might work, if implemented well. Pattern-recognition, on the other hand, seems like nothing ...
15
votes
5answers
4k views

Skew arbitrage: How can you realize the skewness of the underlying?

It's not clear to me how to realize skewness. In other words, how do you implement skew arbitrage? There seems to be no well-known recipe like in volatility arbitrage. Volatility arbitrage (or ...
15
votes
5answers
26k views

Mapping symbols between tickers, Reuters RICs and Bloomberg tickers

Is there any known solution (preferably open source) to map between ticker symbols, Reuters and Bloomberg symbols. For example: Ticker: AAPL Reuters: RSF.ANY.AAPL.OQ Bloomberg: AAPL US Equity ...
15
votes
7answers
993 views

Are there ways to measure the risk aversion of a representative investor, based on publicly available market data?

Are there ways to measure the risk aversion of a representative investor, based on publicly available market data? Public available data could include asset price, volume, and flow data, and may be ...
15
votes
4answers
1k views

Does mean-variance portfolio optimization provide a real edge to those who use it?

Mean-variance optimization (MVO) is a 50+ year concept, and perhaps the first seminal idea of quantitative finance. Still, as far as I know, less than 25% of AUM in the US is quantitatively managed. ...
15
votes
5answers
4k views

Free paper trading site with an API

I've got a quanitative trading model I want to test out in the real stock market. Right now, I'm writing some code to pull "live" quotes from yahoo, feed them to my model, and keep track of the ...
15
votes
5answers
649 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 ...
15
votes
2answers
1k views

How to execute a large futures order?

I am currently trading futures products on some contracts that have low volumes. More accurately, the volumes of working orders in the book are fairly light. I am trying to execute a relatively large ...
15
votes
1answer
1k views

Portfolio optimization with monte carlo sampling from predictive distribution

Let's say we have a predictive distribution of expected returns for N assets. The distribution is not normal. We can interpret the dispersion in the distribution as reflection of our uncertainty (or ...
14
votes
6answers
9k views

Is Scala used in trading systems

I'm curious about high performance computing and consider algo/program trading as an interesting source of information about what are performant technologies that are used to trade the markets. Is ...
14
votes
7answers
9k views

Switching from Matlab to Python for Quant Trading and Research

Has anybody else out there made this switch? I'm considering it right now. What were the negatives and positives of the switch?
14
votes
2answers
2k views

How do we use option price models (like Black-Scholes Model) to make money in practice?

In quantitative finance, we know we have a lot of option price models such as geometric Brownian motion model (Black-Scholes models), stochastic volatility model (Heston), jump diffusion models and so ...
14
votes
5answers
1k views

How to estimate the probability of drawdown / ruin?

A fairly naive approach to estimate the probability of drawdown / ruin is to calculate the probabilities of all the permutations of your sample returns, keeping track of those that hit your drawdown / ...
14
votes
2answers
2k views

What type of analysis is appropriate for assessing the performance time-series forecasts?

When using time-series analysis to forecast some type of value, what types of error analysis are worth considering when trying to determine which models are appropriate. One of the big issues that ...
14
votes
4answers
5k views

Implementing data-structures in a Limit order book

I'm working on implementing a 'LOB' and I'm being very careful about choosing my data-structures so as to maximize performance. Using F# as an example, I need to consider a List versus Array for ...
14
votes
8answers
5k views

Probability of touching

For a vanilla option, I know that the probability of the option expiring in the money is simply the delta of the option... but how would I calculate the probability, without doing monte carlo, of the ...
14
votes
5answers
1k 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: ...
14
votes
1answer
6k views

How to interpret the eigenmatrix from a Johansen cointegration test?

I ran a Johansen cointegration test on 3 instruments, A B and C. The results that I got are: R<=x | Test Stat | 90% | 95% | 99% r=0 --> 36.7 | 18.9 | 21.1 | 25.8 r=1 --> ...
14
votes
2answers
539 views

Who has introduced the term 'vega' and why?

The sensitivity of the option value $V$ to volatility $\sigma$ (a.k.a. vega) is different from the other greeks. It is a derivative with respect to a parameter and not a variable. To quote from Paul ...
14
votes
3answers
1k views

Is there a way to estimate (predict) the half life of a quantitative trading system?

Usually even good performing quant trading strategies work for a while and then return start to shrink. I see two reasons for that which would probably give rise to different analysis: The Strategy ...
14
votes
2answers
1k views

Is there a standard method for getting a continuous time series from futures data?

I would like to be able to analyse futures prices as one continuous time series, so what kinds of methods exist for combining the prices for the various delivery dates into a single time series? I am ...
14
votes
4answers
553 views

Variable Selection in factor models

Let's say you have a dependent variable and many independent variables. What are the preferred metrics for sorting and selecting variables based on explanatory power? Let's say you are not concerned ...
14
votes
2answers
976 views

Parameter estimation of Ornstein–Uhlenbeck and CIR processes

I would like to estimate Ornstein–Uhlenbeck process' parameters via Kalman filter. My process is the following one: $\text{d}x_{t}=\alpha(\theta-x_{t})\text{d}t+\sigma\text{d}W_{t}$ I'm interested ...
13
votes
7answers
2k views

Good quant finance jokes

Have a good quant joke? Share it here. The principle "should be of interest to quants" trumps. I would be particularly keen to learn jokes which involve some nontrivial finance/mathematics. I am ...
13
votes
13answers
7k views

Is “eoddata” a good data source?

Not sure if this is a relevant question for site, but I am looking to move to www.eoddata.com as my data source. If anyone has used it, can you tell me how the data quality is ? I am currently ...
13
votes
5answers
3k views

What C++ math libraries are typically used by quants?

Before you mark question as off-topic, please read it - it is, actually, quant-related. Basically, I'm working on an app that spits out a lot of C++ math. When it comes to simple things like ...
13
votes
5answers
4k views

Proof that you cannot beat a random walk

There is much speculation to what degree financial series are random (and what kind of randomness prevails). I want to turn the question on its head and ask: Is there a mathematical proof that ...
13
votes
6answers
1k views

Setting the r in put-call parity?

Put-call parity is given by $C + Ke^{-r(T-t)} = P + S$. The variables $C$, $P$ and $S$ are directly observable in the market place. $T-t$ follows by the contract specification. The variable $r$ is ...
13
votes
7answers
7k views

What is the “delta” option quoting convention about?

At my work I often see option prices or vols quoted against deltas rather than against strikes. For example for March 2013 Zinc options I might see 5 quotes available for deltas as follows: ...
13
votes
5answers
7k views

How do you explain the volatility smile in the Black-Scholes framework?

Does anyone have an explanation for the currently naturally forming volatility smile (and the variations) in the market?
13
votes
3answers
10k 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 ...
13
votes
4answers
11k views

Why are GARCH models used to forecast volatility if residuals are often correlated?

The answers to this question on forecast assessment suggest that if the sequence of residuals from the forecast are not properly independent, then the model is missing something and further changes ...
13
votes
2answers
965 views

What are the limitations of Gaussian copulas in respect to pricing credit derivatives?

The practice of using Gaussian copulas in modeling credit derivatives has come under a lot of criticism in the past few years. What are the major arguments against using the copula method in this ...
13
votes
6answers
2k views

Formal proof for risk-neutral pricing formula

As you know, the key equation of risk neutral pricing is the following: $\exp^{-rt} S_t = E_Q[\exp^{-rT} S_T | \mathcal{F}_t]$ That is, discounted prices are Q-martingales. It makes real-sense for ...
13
votes
3answers
583 views

Empirical or theoretical quant insights that have shaped your thinking?

What are some quant theoretical or empirical insights that have shaped your thinking or provided a deeper conceptual basis for explaining returns and risk?
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
1answer
4k views

Transformation from the Black-Scholes differential equation to the diffusion equation - and back

I know the derivation of the Black-Scholes differential equation and I understand (most of) the solution of the diffusion equation. What I am missing is the transformation from the Black-Scholes ...
13
votes
4answers
7k views

Are there any good tools for back testing options strategies?

There are all kinds of tools for backtesting linear instruments (like stocks or stock indices). It is a completely different story when it comes to option strategies. Most of the tools used are ...
13
votes
4answers
762 views

Approximately what proportion of a stock’s volatility is explained by market movement?

Assume we decompose the daily (log) returns of a stock as beta times market movement plus an idiosyncratic part. If this is done ex-ante, what proportion of the variance is explained by the market ...
13
votes
2answers
224 views

How reliable is Benford's Law in forecasting crises?

I was recently reading an article about how financial accounting has increasingly deviated from the ratios expected by Benford's Law. (Benford's Law and Decreasing Reliability). The author discusses ...
13
votes
2answers
748 views

Duality between constant rebalanced portfolio (CRP) and corresponding derivative

One of the greatest achievements of modern option pricing theory is finding corresponding dynamical trading strategies in linear instruments with which you can replicate and by that price derivative ...
13
votes
2answers
680 views

How do you distinguish “significant” moves from noise?

How do you distinguish between losses that are within the normal range for day-to-day shifts and situations with a real potential for loss? The specific application I have in mind is pattern ...
13
votes
3answers
4k views

What are the best sources for equity quantitative research?

What are the best sources of quantitative finance research in equities? I will list a couple and note an asterisk if the research is available by request (i.e. non-clients) or online: BAC-Merrill ...
13
votes
2answers
709 views

Concentration risk in credit portfolio

How do you model concentration risk of credit portfolio in IRB/Basel II framework?
13
votes
3answers
4k views

Free market data (delayed or snapshot)

I know there are similar questions but I don't think there are any identical ones. Basically, I'm looking for one of these two things. Delayed market data feed. A tick by tick feed, but delayed by ...
13
votes
3answers
1k 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 ...
13
votes
2answers
921 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 $X_t$ ...
13
votes
1answer
402 views

What should be considered when selecting a windowing function when smoothing a time series?

If one wants to smooth a time series using a window function such as Hanning, Hamming, Blackman etc. what are the considerations for favouring any one window over another?

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