Thanks clacy. Your comment made me think about the concept of trending time series. I cannot say I have evidence of trendiness or lack of it. I don't know if it sone of those old myths passed that get passed around or not like "the trend is your friend" or "losers average losers."
What I did find was a statistical measure which can quantify the persistence of different time series.
http://www.analytics-magazine.org/j...-hurst-exponent-predictability-of-time-series
I've heard some other posters on ET talk about the Hurst exponent. I'll quote from the article:
"The Hurst exponent is a useful statistical method for inferring the properties of a time series without making assumptions about stationarity. It is most useful when used in conjunction with other techniques, and has been applied in a wide range of industries. For example the Hurst exponent is paired with technical indicators to make decisions about trading securities in financial markets; and it is used extensively in the healthcare industry, where it is paired with machine-learning techniques to monitor EEG signals. The Hurst exponent can even be applied in ecology, where it is used to model populations."
Mr. Mansukani has included some useful citations in his article. It is definitely worth a read.
Here are some links for further research:
http://www.bearcave.com/misl/misl_tech/wavelets/hurst/index.html
http://www.r-bloggers.com/exploring-the-market-with-hurst/
http://www.bearcave.com/misl/misl_tech/wavelets/hurst/index.html
From a cursory glance, it seems that the Hurst exponent is no magic bullet. I found at least 2 or 3 implementations of hurst so if one can download time series data into an analysis package, the test can be implemented. However, there are doubts about its accuracy and predictive power. The test itself is an approximation so there is some variance associated with the exponent.
I myself would use it on a securities that I know have some fundamental link (ex: RDS A vs RDS B). Perhaps Hurst is best used as a ranking tool. One could trade the securities that show the highest and lowest Hurst as well as checking for the Hurst exponent over time.
Since most of us are not mathematicians or quants, I would advise traders (myself included) to backtest all of these measures. Cointegration seems to be generally accepted as tool. Correlation is widely accepted. I'm not so sure about Hurst.
If any quants would like to give their professional opinion, it would be appreciated.