If the price moves through one extension level, it may continue moving toward the next. That said, Fibonacci extensions are areas of possible interest. The price may not stop and/or reverse right at the level, but the area around it may be important. For example, the price may move just past the 1.618 level, or pull up just shy of it, before changing directions.
If a trader chooses long entrance, the trader can use the Fibonacci extension levels for an idea of where the stock may go. The same is true for a trader who is short. Fibonacci extension levels can be calculated to give the trader ideas on profit target placement. The trader then has the option to decide whether to cover the position at that level.
Fibonacci extensions can be used for any timeframe or in any market. Typically, clusters of Fibonacci levels indicate a price area that will be significant for the stock, and also for traders in their decision making. Since extension levels can be drawn on different price waves over time, when multiple levels from these different waves converge at one price, that could be a very important area.