Center of Gravity

The Center of Gravity indicator is an oscillator developed by John F. Ehlers.
This indicator results from the author's research on adaptive filters.

This indicator shows the direction of the trend (up or down) and allows the identification of trend reversal points.

This indicator is displayed with its signal (trigger) line.

Calculation Method

It is calculated as follows (normalized form):

where:

• n: Period of the indicator

Example

Interpretation

1. When the center of gravity is in positive territory, recent prices remain above those at the beginning of the period
2. Conversely, when the center of gravity is in negative territory, recent prices remain below those at the beginning of the period
3. When the indicator crosses above its signal line, the trend reverses upward
4. Conversely, when the indicator crosses below its signal line, the trend reverses downward

Notes

The formula used here differs slightly from the one originally published by John F. Ehlers. The result is:

• centered: a zero value indicates that the center of gravity is at the midpoint of the chosen period
• normalized: for a given variation, the value is not proportional to the period

This normalization modifies the scale of the indicator but not its interpretation. The trend reversal signals are identical.