Bull Flag

What it is

A bull flag starts with a strong, fast advance. Price then drifts sideways or slightly lower in a narrow channel instead of giving back much of the move.

The setup is confirmed when a candle closes above the upper edge of the flag. A deep pullback (more than half of the pole) invalidates it.

How ClosedCandle detects it

• Pole: a upward move of at least 3× ATR from its starting extreme to its end extreme, completed within 15 candles.
• Flag: the 5–20 candles after the pole end. Their closes must drift sideways or downward (regression slope), no steeper than 50% of the pole slope, and retrace at most 50% of the pole.
• The channel lines are regressions of the flag highs and lows, shifted outward so every flag candle sits inside. The invalidation level (and measured stop) is the 50% retracement of the pole.
• Confirmed by a close beyond the channel line on the pole side; invalidated by a close beyond the retracement level, or after 15 candles.
• Only closed candles are used; a wick through a line never counts. Once recorded, the detection is never changed.

Full methodology · how setups are measured.