Gann Fans Overview Gann fans are a technical-analysis tool created by W.D. Gann that use angled lines (Gann angles) to project potential support and resistance based on the relationship between price and time. They are drawn from a significant reversal point (a swing high or low) and extend into the future to help gauge trend direction and strength. The 45-degree angle (the 1:1 line) is considered the most important because it represents equal units of price change per unit of time. How Gann Fans are constructed
* Choose a clear reversal point (swing high or swing low) as the fan's origin.
* Use your charting platform’s angle or Gann-fan tool to draw the 1:1 (45°) line from that origin. Align it so it represents one price unit per one time unit on the chart.
* Add additional lines that represent other price:time ratios. Common ratios included in a Gann fan are:
* 1:8, 1:4, 1:3, 1:2 (flatter than 1:1)
* 1:1 (45°)
* 2:1, 3:1, 4:1, 8:1 (steeper than 1:1)
* Many charting packages will draw these standard angles automatically; if not, use the angle tool and the grid analogy: a line rising one square per one time box is 45° (1:1); two time boxes per one price box is flatter (2:1), and so on.
How to read and use Gann Fans
* The 1:1 (45°) line serves as the primary trend indicator:
* Price above the 1:1 line suggests bullish strength.
* Price below the 1:1 line suggests bearish strength.
* Other fan lines act as additional support and resistance levels. If price breaks through one angle, it often trends toward the next angle.
* Use the fan to:
* Anticipate potential reversal or pause levels.
* Assess trend strength by observing how price interacts with the lines.
* Estimate where price might be at future dates, since Gann angles tie price change to time.
Gann Fans vs. Trendlines
* Gann angles are drawn at fixed geometric slopes (uniform rate of price change per time) and are meant to project where a given slope will be in the future.
* Trendlines are drawn by connecting successive swing highs or lows and are adjusted to match recent price action; they are not constrained to specific geometric angles.
* Because Gann angles are uniform, they can be used to forecast price positions on particular dates. Trendlines can be more flexible but less reliable for long-term forecasting.
Limitations and best practices
* Chart scaling matters: if price and time axes aren’t scaled to reflect equal units, the 45° line won’t represent a true 1:1 relationship. Many platforms don’t automatically scale for this.
* Lines spread out over time, so fan levels can become widely spaced and less actionable.
* Price does not always respect fan lines; they sometimes fail to mark significant support/resistance.
* Use Gann fans alongside other technical tools (moving averages, price-action patterns, momentum indicators) and sound risk management.
* Verify the 45° alignment with your platform’s angle tool when precision matters.
Key takeaways
* Gann fans are a set of angled lines based on price:time ratios used to identify potential support and resistance and to assess trend strength.
* The 1:1 (45°) line is central: staying above it is bullish, staying below is bearish.
* Additional lines (e.g., 2:1, 3:1, 4:1 and their inverses) provide successive targets if price breaks an angle.
* They require careful attention to chart scaling and should be combined with other analysis methods for trading decisions.
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