How it works
On every closed bar it measures how far price reached over the next bars in earlier history, in ATR. It takes the 50th, 80th and 95th percentiles and draws them from the last close, scaled to current volatility.
What you see
- The fan The core band (50%) holds the range price stayed inside in half of past windows. The wide band (80%) is the main band. The extreme band (95%, dotted) marks rare, stretched moves. End labels give the wide-band price and its distance from the last close.
- Previous fan A faint dotted outline of the wide band as it looked one horizon ago. Compare it with the candles that followed.
- Historical stop ruler Two dashed lines, long and short, at the distance price moved against a position in only (100 - Survival)% of past windows. With the default 70% that is about 30%. It is a statistical noise distance, not a stop-loss recommendation.
- Fan Check chip Shows how often price stayed inside the wide band recently, against the target (80% by default). Status reads On target, Bands running tight or Bands running wide.
How to use it
- Read the wide band It shows where price has usually stayed over the next N bars. A move beyond it is rarer than usual in that market.
- Compare with your plan If a target sits far outside the wide band, price has rarely got there within this horizon.
- Check the chip first Held well below the target means the bands have been too tight lately. Well above means too wide.
- Use the previous fan as a reality check See how price actually behaved inside the last fan.
- Pick a horizon for your style 20 bars is roughly one trading day on 1-hour charts and one trading month on daily charts.
- Check each market Volatility and liquidity differ across crypto, forex and indices, so check the chip on each symbol and timeframe.
Settings
- Horizon 20 bars (6-100). Larger means a longer, wider fan.
- ATR length 14. Only scales past moves to current volatility.
- History samples 1000 (100-1000). More is steadier but slower to adapt.
- Band percentages 50, 80 and 95 by default.
- Survival 70% (60-99). Higher puts the stop line further away.
- Entry price 0 uses the last close. Optional: measure the ruler from your own entry.
- Fan updates Bar close by default. Every tick makes the fan move intrabar.
Alerts
- Up-move beyond wide range and down-move beyond wide range.
- Each fires at bar close, on the first bar where the window that just ended reached farther than the wide band drawn when it began.
- They report something that has already happened and are not forward signals. Use Once Per Bar Close.
Good to know
- The fan is built from past data and assumes the future behaves roughly like the recent past. News, gaps and regime changes can break it.
- It has no directional bias. It shows how far, not which way.
- Windows overlap, so the effective sample size is smaller than the number shown, especially for the 95% band.
- Use standard candles. Heikin Ashi, Renko and similar types distort the data.
- The fan is drawn at the last bar and extends into empty chart space on the right.
- No backtests or profitability tests have been run. Use the Fan Check as your own live calibration.
Try it on your own chart.
Add it from TradingView and see it on your symbols and timeframes.
Questions? Message me on TradingView chat.
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