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Harmonic Patterns are one of the powerful advanced price action techniques that are used to detect reactions. The thing that works about Harmonic Patterns is that they use the confluence method, meaning that they expect reactions from clusters of certain levels defined by Fibonacci retracements. The reason they work has nothing to do with mystic or magic whatsoever, it is simply the fact that Fibonacci retracements are used by many traders and their visibility makes reactions more likely, thus increasing the predictive power of the patterns. However, only using Harmonic Patterns on their own might not be sufficient as we will see below, they are best combined with contrarian indicators to increase the chances of a profitable trade.

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### Introduction to the Fibonacci Sequence

Leonardo Bonacci, known as Leonardo Fibonacci has developed a sequence out of rabbit mating which formed the basis for many mathematical observations. The sequence follows this distinct pattern:

The numbers are found by adding the previous two numbers behind them. In the case of 13, it is calculated as 8 + 5, hence the formula is:

The beauty of these numbers is a certain ratio, called the golden ratio. If we take any two successive numbers in the sequence, their ratio (Xn / Xn-1) gets closer to 1.618 which is what we call the golden ratio:

It is not important how we got to trading from these patterns as much as how important they are, therefore, we will discuss the ratios from a financial trading perspective. Let us keep the 1.618 in mind as for the moment it is one of the two most important ratios that we will use in trading. Our job now is to find the rest of the significant ratios useful to us in trading. They are all variations of 1.618 and its reciprocal 0.618. Notice how the reciprocal of 1.618 is simply 0.618. A reciprocal is when you divide 1 by the number. The below table summarizes the rest of the ratios and how we got them:

We will now proceed to define the Crab Pattern and how to detect and trade it.

### The Crab Pattern

The Crab pattern is an interesting configuration that takes advantage of extended moves to detect an imminent reversal level. It is defined as:

**The first leg should retrace back 61.8%.****The second leg should also retrace back 61.8%.****The third leg should retrace back 261.8%.****The whole retracement from the beginning to the top should retrace 161.8%.**

Here is another example of a bearish Crab that has provided a reaction. Sometimes, harmonic patterns do provide reversals, but we are not supposed to expect that from them. They are merely used for reactions just like the one in the below chart.

The figure above shows a nice reaction after prices reached 161.8%. The Crab pattern benefits from the time factor as extended moves are bound to correct sometime. It is not that easy to detect nor is it common but when it occurs, it definitely adds value to our trading.

It becomes clear that a bullish Crab resembles an M while a bearish Crab resembles a W. We expect a form of reaction around the D point. The pattern is always composed of five points in time XABCD where we trade the last point and manage our risk according to specific measure discussed in the last part of the article.

### Detecting the Crab Pattern

The Crab Pattern can start to be detected around the middle of point C. Therefore, we have enough time to act on it without any hindsight bias or delay. The below plots show how to detect one across time:

The first step above is simply detecting an impulse move following by a reactionary move that should retrace back to 61.8%. After that we have to wait whether the reaction will retrace back again to 61.8% of the new leg or not.

Having retraced back of the new leg, we are now looking for 261.8% retracement of the new leg and the break of the B point. We should start to see about now the formation of an M (Bullish Crab).

Now, we can even draw the Crab. All we need is the expected reaction from the D point defined as the 161.8% retracement from the X point to the A point as well as the 261.8% retracement of the BC move. This means that the length of the CD leg should equal 2.618x the length of the BC leg.

And finally, we should manage the reaction according to the risk management measures outlined in the last part of the article.

### Combining the Crab with the RSI

Having a Crab Pattern at its D point (pending reaction) and an RSI around extremes or in divergence is a good confirmation of the trade and is a conviction enhancer. But what is the Relative Strength Index?

The RSI is without a doubt the most famous momentum indicator out there, and this is to be expected as it has many strengths especially in ranging markets. It is also bounded between 0 and 100 which makes it easier to interpret. Also, the fact that it is famous, contributes to its potential.

This is because the more traders and portfolio managers look at the RSI, the more people will react based on its signals and this in turn can push market prices. Of course, we cannot prove this idea, but it is intuitive as one of the basis of Technical Analysis is that it is self-fulfilling.

The RSI is calculated using a rather simple way. We first start by taking price differences of one period. This means that we have to subtract every closing price from the one before it. Then, we will calculate the smoothed average of the positive differences and divide it by the smoothed average of the negative differences. The last calculation gives us the Relative Strength which is then used in the RSI formula to be transformed into a measure between 0 and 100.

### Risk Management on the Crab Pattern

Trading on the patterns requires touching the implied reversal zone, also referred to as Potential Reversal Zone — PRZ. A basic tule of thumb that we can follow when trading is to place two targets with the first one being at 38.2% of the top to bottom (or bottom to top) retracement and the second one being at 61.8%. The stop will be placed at half the distance between the entry and the second target thus ensuring a 2.0 risk reward ratio. I generally take half the profits at the first target and move the stop to breakeven, that way I ensure that the trade never loses money in case the price comes back unfavorably. Below is an example on the simples of Harmonic Patterns, the ABCD pattern showing clear risk management.

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### Summary

To sum up, what I am trying to do is to simply contribute to the world of objective technical analysis which is promoting more transparent techniques and strategies that need to be back-tested before being implemented. This way, technical analysis will get rid of the bad reputation of being subjective and scientifically unfounded.

I recommend you always follow the the below steps whenever you come across a trading technique or strategy:

*Have a critical mindset and get rid of any emotions.**Back-test it using real life simulation and conditions.**If you find potential, try optimizing it and running a forward test.**Always include transaction costs and any slippage simulation in your tests.**Always include risk management and position sizing in your tests.*

Finally, even after making sure of the above, stay careful and monitor the strategy because market dynamics may shift and make the strategy unprofitable.