X to A – the movement starts with X to A and there are no specifics for identifying the X to A leg of the Gartley pattern
A to B – this is where Fibonacci becomes relevant to the pattern. The distance between A and B should be close to 61.8% of the size of the movement from X to A
B to C – this movement should be a retracement of 38.2% or 88.6% of the movement of A to B. If the B to C move retraces above point A, the Gartley pattern is void
C to D – this should be a 127.2% to 161.8% extension of the B to C leg
A to D – when C to D is complete, you should measure the A to D move overall, which should be a 78.6% retracement of the price change of X to A
Identifying the Gartley pattern
The percentages used are achieved by looking at the Fibonacci sequence. 61.8% is gained by dividing a number in the sequence by the number immediately to its right and multiplying the result by 100. For example, if you divide 89 by 144, you get 0.618 and if you multiply that by 100, the result is 61.8%.
38.2 is achieved by dividing a number in the sequence by the number two places to its right, for example 55 divided by 144 gives 0.3819, which can be rounded to 0.382 and when multiplied by 100, gives us 38.2%.
127.2 is the result of the square root of 1.618 multiplied by 100, and 78.6 is achieved by the square root of 0.618 multiplied by 100. 127.2% is the target level that a trader would ideally like the price to rise to after it hits point D.