As I come across comments on the charts in which traders overlay simple geometries, I thought I should point out to the ones that have been most important in my experience, in terms of how reliable they have been.
THE STANDARD AB=CD PATTERN:
To start the enumeration of the most common ones, let's name the most obvious ones, the a-b = c-d symmetrical pattern.
In its most mundane form, the a-b = c-d represents a balancing of a geometric form in which the ab segment is reproduced following a shallower retracement in the order of 0.382 to 0.786 Fibonacci range. What ensues is simply a cut-and-paste version of the a-b segment into a c-d segment.
In the chart, you will see this in the large RED dashed figure.
REITERATION OF THE STANDARD AB=CD PATTERN:
While there is a possibility of reiteration of the ab segment into a c-d, then a e-f segment (see YELLOW pattern in the price field), this represents a lesser occurrence.
FIBONACCI CAN HELP MEASURE THE EXTENT OF THE PATTERN:
The type-A trader might be tempted to look for a perfect replication of a-b into c-d, but this is rarely the case, as the market will expand at its own whim. Be flexible and let the market breathe a little.
Still, the trader interested to keep a pulse on these development should remain on guard with such Fibonacci-paced extensions as 1.272, 1.414 and 1.618 x the b-c segment, or in the case of a reiteration, 1.272, 1.414 or 1.618 x d-e segment.
MOST RELIABLE SIMPLE GEOMETRY:
In my experience, most novice pattern traders have calibrated their visual cortices to scan for forward-moving price action, over which they draw a line and look for a symmetrical repetition, so as to decipher the all-too familiar a-b = c-d symmetrical pattern.
Instead, I recommend that you seek out not the FORE-ward, but instead the BACK-ward leaning price action. In this geometry, you will have to reverse your mind's eyes, looking for a symmetrical repetition in which the a-b = c-b segment is drawn lines leaning in reverse of the standard symmetrical a-b = c-d pattern.
This pattern has a name: The One2One (purple in the chat)
OVERALL:
In my experience, the completion of these symmetrical patterns are rarer, but accompanied by a most forceful price reaction upon completion of the reversed a-b = c-d geometry.
Think backward. Stay ahead.
David Alcindor Predictive Analysis & Forecasting Denver, Colorado - USA