The Gann Fan is a technical analysis tool created by WD Gann. The tool is comprised of 9 diagonal lines (extending indefinitely) designed to show different support and resistance
levels on a chart. These angles -drawn from main tops and bottoms- divide time and price into proportionate parts and are often used to predict areas of support and resistance, key tops and bottoms and future price moves. Please note that the chart needs to be scaled properly to ensure the market has a square relationship.
The method is based on the notion that markets rotate from angle to angle and when an angle is broken, price moves towards the next one. The most noteworthy angle is the 1x1 or the 45° angle, which represents one unit of price for one unit of time. A change in the direction of price is expected when the market reaches an equal unit of time and price, up or down. During an uptrend, if price remains above an ascending angle, the market is considered bullish and vice versa. TradingView has a smart tool
that allows users to draw up to 9 customizable angles on a chart.