Fibonacci retracement is best used when a trend is happening, and the level that often appears is in area 50, 61.8. when the price touches that number and there is a candel pinbar then you can open a position but if the price breaks that number then the price will continue to go up or down
Hy, what a coincidence I am also studying the Fibonacci retracement. Maybe the numbers you mean are usually called the Golden Ratio. And I will explain a little about the Golden ratio based on what I know.
Strong trend: the main trend is called strong if retracement is "stuck" at the level of 0.382 (38.2% of the Main Trend). Under these conditions, prices have a high probability of moving at full strength in the direction of the main trend.
Normal trend: the main trend is said to have normal strength if the price is able to approach the FR 0.5 limit. In this condition, the trend is likely to continue the price movement in the direction of the Main Trend before experiencing consolidation (sideways).
Weak trend: if the retracement can break through the Golden Ratio 0.618 level, the main trend is predicted to enter the consolidation period (sideways) soon.
Now, the next question, what if for example Retracement managed to break the FR 0.618, FR 0.786 limit, even reaching 100% of the main trend? What will happen to the next price movement?
Then the answer is, trend reversals are taking place