These are supporting indicators that can help you to analyse the situation of the price graph directly in your terminal. There you can find the icon "Fibonacci lines" (on the top panel of your terminal is a button with dotted lines and the icon F). So, Fibonacci retracement is a level that shows exactly how the trend may change (see) or to what level a rebound of prices may occur (see). That is, there is a trend (see), a "corridor of the price graph." We may not describe it two straight lines, but we understand that the price may at any time to bounce upward or downward from the existing borders of the trend. Therefore, it's better to use a few lines with the help of the button mentioned above. With Fibonacci retracement, you need to identify 23.6%, 32.8%, 50% and 61.8% of the range of the current trend and establish new lines at these levels above the upper boundary and under the lower. As a rule, it can be quite difficult for newcomers to work with these lines, however you soon learn to understand this valuable information about price behaviour. To learm more about this trade system, you can read the book “The New Fibonacci Trader” by Robert Fisher.