Structure zones: FVG, order blocks, breakers

Structure zones are price areas left behind by fast moves and structure breaks. AK FlowBook Full tracks four kinds: fair-value gaps (FVG), order blocks (OB), breaker blocks and the 3-Drive pattern zone (PRZ). The zones always run in the background, because the setup engine uses them as levels. Their boxes are off by default to keep the chart clean.

Market structure (background)

The indicator tracks confirmed swing highs and lows (Confirmed pivot length, set by the market preset unless Manual). A close above the last swing high is a break up; a close below the last swing low is a break down. Full uses this internally for order blocks, the setup engine and the premium/discount reading. It does not draw BOS or CHoCH markers. (Lite does; see the Lite guide.)

Swings are confirmed a few bars after they happen, so structure readings lag by that many bars.

Fair-value gaps (FVG)

A bullish FVG forms when a bar's low is above the high of the bar two bars earlier, leaving a gap of at least Minimum FVG (ATR) (0.12 ATR). A bearish FVG is the mirror.

• Only the most recent FVG on each side is kept.
• It stays active until price closes through it or it is older than Zone maximum life (bars) (250).
• With Show FVG zones on: teal box for bullish, orange box for bearish, extending right while active.

Order blocks (OB)

When structure breaks up, the last bearish candle within OB source search (12) bars before the break becomes a bullish order block. A break down makes the last bullish candle a bearish order block.

• Only the most recent OB on each side is kept, with the same active rules as FVGs.
• With Show order-block zones on: green box for bullish, red box for bearish.

Breaker blocks

When price closes through an order block, that block flips:

• A bearish OB closed through upward becomes a bullish breaker (BRK+, green).
• A bullish OB closed through downward becomes a bearish breaker (BRK−, red).
• A breaker ends when price closes back through it.

Turn on Draw breaker boxes on chart to see them. Show breaker blocks (failed OBs) runs the logic even when the boxes are hidden.

3-Drive pattern zone (PRZ)

The 3-Drive detector looks for three pushes in the same direction with similar size and timing:

• three rising swing highs with rising pullback lows (bearish pattern), or three falling lows with falling pullback highs (bullish pattern),
• each drive similar in size within Leg symmetry tolerance (0.18) and similar in time within Time symmetry tolerance (0.45),
• pullbacks of a reasonable depth between the drives.

The zone (PRZ) is the extreme of the third drive, plus or minus PRZ half-width (ATR) (0.25 ATR). It stays relevant for PRZ max age (bars) (60).

The 3D PRZ label (green below for a bullish pattern, red above for a bearish one) appears after the swing is confirmed and is drawn back on the swing bar. It is hidden in Elite marker mode; see Display and marker modes. An optional alert exists (3-Drive PRZ in the Alerts group).

How the zones are used

• The setup engine counts a touch of an active FVG, OB, breaker, imbalance zone or PRZ as being "at a level". Zone setups belong to the MIT family (FVG/OB mitigation) or the 3DP family (3-Drive). See Setup context.
• D~ markers, by default, appear only near a level; active FVGs and OBs count as levels for that filter.
• On your own reading, treat zones as areas of interest, not as walls. Price often trades into a zone, and sometimes straight through it.

Settings

Education only. Not financial advice. Trading futures and CFDs carries a high risk of loss.