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Is Anyone Using The Hurst Exponent?

Hello All,

The Hurst Exponent can be calculated for a time series as a value for 0 to 1. A value of 0.5 says the time series is a random walk, < 0.5 that it is mean-reverting, and > 0.5 that it is trending. I've over-simplified a bit so see these references:

'Rescaled Range Analysis: A Method for Detecting Persistence, Randomness, or Mean Reversion in Financial Markets' http://blogs.cfainstitute.org/investor/2013/01/30/rescaled-range-analysis-a-method-for-detecting-persistence-randomness-or-mean-reversion-in-financial-markets/

'Some comments on Hurst exponent and the long memory processes on
capital markets' http://www.ual.es/~jgarcia/index_archivos/HURST.pdf

I've copied some code from the PyEEG project http://code.google.com/p/pyeeg/ but initially I am getting Hurst Exponent values for SPY and for individual stocks that are around 0.7. In both references above the S&P 500 has a calculated Hurst Exponent of 0.49 - 0.5.

What am I doing wrong? And is there a trading method here?

Regards,

Peter

5 responses

Hi,

If I remember correctly, there are a lot of methodologies to "estimate" the Hurst Exponent. You have some of them listed here: https://www1.ethz.ch/mosaic/research/docs/Racine2011.pdf‎
I have not seen your code, but if the code is right, maybe you have a "biased" Hurst Exponent because of the sample data you are using...
You have a comparative article about this problem: www.foibg.com/ijitk/ijitk-vol05/ijitk05-4-p05.pdf‎

BTW, as far as I know (but I am new here) there is not an example using it here...

Cheers.

Damián.

Hello Damián,

Thanks for the links. They work but only if I delete '%E2%80%8E' from the end i.e.:

https://www1.ethz.ch/mosaic/research/docs/Racine2011.pdf

http://www.foibg.com/ijitk/ijitk-vol05/ijitk05-4-p05.pdf

Regards,

Peter

(If anyone is curious this is due to the UTF-8 left-to-right mark (LRM). See: http://en.wikipedia.org/wiki/Left-to-right_mark )

Hi Peter, usually use logarithm return of the stock prices as a time series to feed into the model. I saw that you're using the prices directly. This might be the problem.

I've dived into some Hurst Academic papers, that's quite brilliant.

Does anyone has good results by filtering market ?

At which timeframe does it mostly apply, I think it's mostly on daily/weekly isn't?

Peter - I agree with Zao. From my understanding, you should be using the log return not prices directly.