Instantaneous Trend Line and Dominant-Cycle Smoothing

Summary

This short description explains the intuition behind John Ehlers’ Instantaneous Trend Line. It presents the indicator as a smoothing average designed to remove the dominant market cycle. The key idea is to average observations across a period matching that cycle: values above and below the midpoint then balance, so their contributions sum to zero.

The text also gives a frequency-domain interpretation. A simple rectangular-window average has a sinc-shaped Fourier response, and the proposed design places its first zero at the dominant cycle. This is a conceptual explanation rather than a full specification: it provides no calculation procedure for estimating the cycle, parameter guidance, trading rules, or empirical results. Readers would need those details before implementing the indicator or judging its usefulness in a strategy.

Key ideas

• The indicator is described as a smoothing average designed to cancel the dominant cycle.
• Averaging across a full cycle can balance observations above and below the midpoint.
• The frequency-domain explanation places the average’s first response null at the dominant cycle.
• The description gives intuition but not implementation details or evidence of trading performance.

Tags

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.