Consider a standard technical indicator such as Bollinger Bands. We could view the market--or a stock--to be a buy when it closes above its upper band and a sell when it closes below its lower band. The idea is that if the market is more or less than two standard deviations from its recent average price, that is indicative of a trend.
But suppose we view the bands differently. Suppose we look at every stock in the NYSE universe and identify how many close each day above and below their upper and lower bands. Now we've turned the strength/weakness measure into a breadth measure.
I've collected those data for about three years and have noticed a pattern that no one talks about. It's when we have very few stocks trading above their bands that next 5-20 day returns are most favorable. And when we have very few stocks trading below their bands, the next 3-5 day returns are most favorable. Interestingly, the correlation between the daily number of stocks trading above and below their bands is a very modest -.20. In other words, breadth strength and breadth weakness are independent variables.
Now the door is open to similar analyses using common technical indicators. By viewing presence/absence of strength/weakness uniquely, we can find unique relationships. The absence of strength or weakness may be as important to markets as their presence.
This is what trading psychology is meant to be. Not a stale rehashing of the need to be disciplined, but the positive development of our greatest cognitive and behavioral capacities. Creativity is all about asking new and better questions.
Further Reading:
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