It is my goal to bring science to the art of trading. The analysis span used to find the dominant cycle is mostly a factor of the dynamic range of the measurement technique. Since we are using sampled data, it matters very little whether those samples are daily, weekly or hourly bars. Thus, one can trade cycles over any period he is comfortable with and expect the performance per trade to be proportional to the length of the cycle. I don't only believe cycles work, I know they work.
Cyclic behavior is ubiquitous.
The natural response to any physical disturbance is harmonic motion. For example, if you strum a rubber band stretched between your fingers or bend a ruler over the edge of a table and release it, you create an oscillation. This cyclic reaction to disturbance holds from the atomic level to colliding galaxies. Since there are plenty of disturbances in the market, there is no reason to think that harmonic motion should not apply here also. The two solutions are partial differential equations called the diffusion equation and the telegraphers' equation .