White Paper - "Trading Seasonality" - Conclusion
Seasonality is a phenomenon that is measurable, but it is not a causal factor. Seasonal cycles do not cause markets to move. They are rather a function of other factors, known or unknown, which over and over again influence the direction of stock prices. We believe that if traders limit their trading to those periods where seasonal tendencies are consistent, the chances of post "trigger" success are better than otherwise.
As is true with most of the areas of Wall Street analysis, more research needs to be done in the areas of technical analysis in general and seasonality specifically. We hope this text encourages many to pursue their understanding and experience with seasonal trading.