Gann Fan: Scaling and Illustrative Examples

What a Gann Fan actually is

A Gann Fan draws diagonal price-to-time reference lines from an anchor, commonly a swing high or low. W.D. Gann developed the approach. The 1x1 means one price unit per time unit under the selected scale; it is not a fixed horizontal price.

The angles and their price-to-time ratios

Ratios describe how fast each line rises or falls from the anchor. In the example below, the steeper line advances twice as fast as the base line and the flatter line half as fast. Their angles on screen depend on chart scaling; ratio labels do not establish fixed screen angles.

The standard fan has nine lines. Each line is named by a ratio of price units to time units. A 2x1 line rises two price units for each one time unit. A 1x2 line rises one price unit for each two time units. The 1x1 line is the reference.

The angle column is easy to misuse. Screen angles change when you zoom or stretch a chart, so the ratio is the thing that stays fixed. That is why this page works from slopes in points per bar and not from degrees.

Setting the scale: the step everyone skips

Choose and record the scale explicitly. No universally best Nifty or Bank Nifty price-per-bar unit is verified here.

How to draw a Gann Fan, step by step

• Choose the anchor: a clear swing low for a rising fan or a clear swing high for a falling fan. Write down its date and price.
• Choose the chart interval, such as daily bars, and keep it fixed.
• Set the scale, meaning how many price points one bar represents on the 1x1 line. Some traders take it from a recent swing, some from the average bar range, some set it by hand. Record the method.
• Draw the nine lines from the anchor. Many charting platforms let you drag a second point that sets the 1x1 line. Read your platform's help to see how yours does it.
• Save a screenshot and the numbers: anchor price, anchor date, scale, interval.
• Check later whether price respected, ignored or crossed each line, and write down what happened.

If a second trader draws the fan from the same anchor with a different scale, the lines land in different places. Neither is wrong. They are different drawings. This is also why a Gann Fan result cannot be compared across people unless the scale is shared.

Worked Example: An Assumed Daily Fan

Illustrative fan on a daily chart, with each bar representing a trading day: assume anchor 16,828, base rise 50 points per bar, double slope 100 and half slope 25. Add elapsed bars multiplied by slope to the anchor.

More lines from the same assumed fan

The table above uses three lines. Here are more lines for the same invented fan: anchor 16,828 and a 1x1 slope of 50 points per bar. Each value is the anchor plus the number of bars times the line's slope. The 3x1 slope is 150 points per bar (3 x 50), and the 1x4 slope is 12.5 points per bar (50 / 4).

Notice how fast the lines spread apart. After 20 bars the 3x1 line is at 19,828 and the 1x1 line at 17,828, a gap of 2,000 points (19,828 - 17,828). A real chart rarely follows any single line for that long, which is one reason fans need frequent redrawing.

A falling fan from a swing high

A fan drawn from a swing high slopes down. The same arithmetic applies but you subtract. With an invented anchor of 19,000 and a 1x1 slope of 50 points per bar, the 1x1 line after 10 bars is 19,000 - (10 x 50) = 18,500, and the 2x1 line is 19,000 - (10 x 100) = 18,000. Lines that fall faster are the 2x1, 3x1 and steeper ones.

Why Fan Lines Do Not Price Options

A fan line does not forecast an option premium. Any option example also needs independently assumed prices, quantity, expiry and costs.

How traders read a Gann Fan

People who use the fan treat each line as a possible area where price may find support or resistance. A common reading is that price above the 1x1 line shows a stronger trend and price below it a weaker one. Some traders watch for a close below one line and then look for the next line down as a possible area. These are descriptions of how the tool is used, not forecasts, and this page gives no trading signals.

• A line is a reference slope. It has no force of its own to hold price.
• Price can pass through several lines in one session.
• A confirmed close below a line does not mean an order would fill at the line. Gaps and fast moves cause fills away from it.
• Each line is a different price on each bar, so a stop based on a line has to be updated by the bar.

Gann Fan vs trendlines and Fibonacci

The fan fixes the slopes in advance, so the trader chooses fewer things: the anchor and the scale. Both choices still change the result a lot.

Applying a Fan to Stock Charts

The same arithmetic applies to a stock chart after specifying its anchor and price-to-time scale. A company name does not make invented inputs historical data.

Check Expiry Separately From Chart Settings

Read the selected contract date and quantity separately. Bank Nifty has monthly and quarterly options, with its weekly series discontinued.

Combining Gann angles with other tools

Momentum or volume can add context, but several indicators can reuse the same prices. Agreement is not proof of a profitable edge.

Common mistakes with Gann Fans

• Changing the scale after the fact until a line fits a past turning point.
• Using the degree values on a chart that is zoomed or stretched.
• Redrawing the fan from a new anchor and forgetting the old one, so failed fans disappear from your records.
• Treating a touch of a line as a reason to take a trade, without a stop or reason of your own.
• Mixing a daily-chart fan with intraday entries.

Journaling a Gann Fan trade

If you use a fan in a decision, record the anchor price and date, the interval, the scale and the line you relied on. Add your entry, stop and exit, and later note whether price respected the line. Over many trades you can see whether this idea helped you or only felt convincing. OneTradeJournal records trades by hand, with strategy and notes fields. It draws no fans, has no chart data and gives no signals. See also the Gann Square of Nine page for a different Gann tool, and the risk-reward guide for sizing the stop.

Limitations, false signals and honest expectations

Changing the anchor shifts the lines. Price can cross an angle and reverse. Record failed crossings, execution differences and costs as well as successful examples.

Questions About Gann Fans

Sources

• TradingView: Gann fan drawing tool (checked 16 Oct 2026)
• NSE: Bank Nifty option cycles (checked 16 Oct 2026)