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Investing/Strategies / Mechanical Investing
|Subject: Re: performance of screens||Date: 2/12/2013 8:09 AM|
|Author: ProphetWise||Number: 241549 of 253154|
I agree with Elan in the assertion that you shouldn't make any general assumptions concerning screens based on bill2m's spreadsheet. As others have noted, a screen that does well as weekly hold, may not do well for other holding periods. As well, screen performance over time will vary depending on start date.
Elan's real point is that you can't make long term inferences about screen performance from bill2m's report of recent screen performance. That's why he recommends long term back-tests.
Some of the assumptions underlying each screen reflect investor's preferences. In the short run, the market may prefer one set of stock characteristics over another (value, growth, cyclical, momentum, etc). Bill2m's spreadsheet provides insight into those short term preferences.
Some members of this board try to determine what stock selection methods appear most effective now. They like to adjust their screen selection to suit current preferences as reflected in the spreadsheets. Use care over time, as those preferences (frequently dictated by institutional traders) can change quite rapidly.
Using this method will require considerably more effort and may not produce superior results over choosing one or more screens that have performed reliably over extended time periods.
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