Fibonacci Percentage Retracements

Fibonacci retracements can identify potential support/ resistance levels.

The most commonly used Fibonacci levels are 61.8%, 50% and 38.2% with other percentages sometimes serving as secondary levels (76.4%, 23.6%).  In a strong trend, a minimum retracement is usually around 38%; while in a weaker trend, the maximum percentage retracement is usually 62%.  A complete retracement (100%) of a previous bull or bear market also should mark an important supprt or resistance area.

Source: Technical Analysis of the Financial Markets, John Murphy, p. 336-338