Fibonacci numbers are the result of work by Leonardo Fibonacci around 1170 while studying the Great Pyramid of Gizeh. The fibonacci numbers are a numerical sequence shown below:
1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144... and so on to infinity
This sequence of numbers appears to have little importance to the untrained eye however there are many remarkable properties:
1. The next number in the fibonacci sequence is obtained by adding the current and previous number, e.g. 1+2=3, 8+13=21
2. After the 1st couple of numbers, if you take the ratio of any two consecutive numbers you get approx 0.618, e.g.
3/5= 0.6
5/8= 0.625
8/13= 0.615 and so on
3. If you take the ration of two alternate numbers you get approx 0.382, e.g.
3/8= 0.375
5/13= 0.385
8/21= 0.380 and so on
It has been found that the Fibonacci numbers sequence can be used to predict many things that occur in nature, science, math's and engineering. In trading the sequence is used as the basis for the Elliot Wave Theory which is used to predict stock market patterns.
In the technical analysis of stocks Fibonacci numbers are commonly used to determine potential support, resistance, and price objectives.
A 38.2% retracement usually implies that the prior trend will continue, and are considered natural retracements in a healthy trend.
A 61.8% retracement implies a new trend is establishing itself.
A 50% retracement implies indecision.
The average trader does not need to know all the details about the sequence because all the calculations are usually performed by the trading tool (if it incorporates fibonacci numbers). However, the trader must understand how to apply the retracement levels in order to make trading decisions.