Here is an example of the Fibo Extensions Indicator doing its job.

The market turned around at 100% of A-B in other words AB=CD, but it could happen at other numbers as well. What you will see though is that the Fibonacci numbers just keep appearing over and over.

What I have shown here is that A-B is shown by the green percentage levels in relation to the current ZZ leg. These numbers show where to take profit, if the market goes through these levels like a freight train, look to the next level as to whether it will stop there. Another approach is to set your TP at perhaps 61.8% as a safer option. This 61.8% number does come up a lot, it may not be the end of the current trend direction but could be a retracement.

The white percentages D-C is the retracement from D of the last ZZ leg, smaller numbers here indicate the trend is likely to continue in the direction of D.

B-C Aqua percentages is showing the retracement from D based on the last B-C leg. This could be a retracement or where the continuation of the trend could go to.

Of course, all these ABCD numbers will flip the other way in an uptrend. Just look where 0% is and work from there.