Break Of Structure Indicator: Closing Past An Old Swing

Written by Dominic Walsh · Published 2 Jun 2026 · Last updated 9 Sep 2026

The break of structure indicator keeps a memory. Every confirmed fractal swing goes into a list, up to `MaxSwingsToTrack` of them. When a close takes price beyond one of those stored levels, the code marks the bar and draws a line at the level that broke.

This build ships as a compiled .ex4 for MT4 and .ex5 for MT5; the screenshots below come from EURUSD H1.

Platforms	MT4 (.ex4) + MT5 (.ex5)
Chart window	Main price chart
Plots	2: BoS Buy, BoS Sell
Alerts	popup, push notification, email, sound
Inputs	15

What the Break of Structure Indicator draws on the chart

BoS Buy places a lime arrow on the close that cleared a stored swing high.

BoS Sell places a red arrow on the close that broke a stored swing low.

OBJ_TREND lines mark the broken levels, in `BoSLineColorBull` or `BoSLineColorBear`.

`DrawBoSLines` turns those lines off if you want the marks alone.

• BoS Buy: arrow, lime, width 2, arrow code 233
• BoS Sell: arrow, red, width 2, arrow code 234

How the Break of Structure Indicator calculates its values

Collecting the swings

A swing high needs `FractalLookback` `3` bars on each side that fail to reach it. Each confirmed swing goes into a list with its price and its bar time. Duplicate times get rejected, so one bar cannot register twice.

Testing the close against memory

For each bar the code walks the stored swing highs. A stored high older than this bar, sitting below the current close, counts as broken. The swing low test mirrors it. Comparing by time rather than index keeps the memory honest.

Capping the drawing

`MaxSwingsToTrack` `50` bounds the memory itself. `MaxBoSLines` `20` bounds how many level lines stay on the chart. Both caps exist because a long history would otherwise fill the chart with objects.

How to read the signals

A mark means price closed past a level that had already formed.

The drawn line shows exactly which swing gave way.

Several marks in a row usually mean one move clearing a cluster of old swings.

Raise `FractalLookback` to store only the larger swings.

Alert channels in this build: popup, push notification, email and sound, one message per closed bar.

`EnableAlerts` starts on and `EnablePopup` carries the text. `EnablePushNotify`, `EnableEmail` and `EnableSound` begin false. `SoundFile` picks the clip. The break test reads closed bars, and the guard allows one message per bar.

Every Break of Structure Indicator input

Core settings

Setting	What it does	Default
FractalLookback	Fractal lookback (N bars each side). Bars each side of a fractal swing, default `3`.	3
MaxSwingsToTrack	Max swing highs/lows to remember. How many swings the memory holds, default `50`.	50
MaxBoSLines	Max BoS lines kept on chart. Cap on the break lines kept on the chart, default `20`.	20

Display settings

Setting	What it does	Default
ArrowOffsetPoints	Arrow distance from bar high/low (points). Mark distance from the bar in points, default `20.0`.	20.0
DrawBoSLines	Draw HLINE at broken swing levels. Draws a line at each broken level, default `true`.	on
BoSLineColorBull	Colour for a bullish break line, default lime.	lime
BoSLineColorBear	Colour for a bearish break line, default red.	red
BoSLineWidth	Break line width, default `1`.	1
BoSLineStyle	Break line style, dotted by default.	STYLE_DOT

Alert settings

Setting	What it does	Default
EnableAlerts	Master switch for the structure break alerts, default `true`.	on
EnablePopup	Terminal dialog on a structure break, default `true`.	on
EnablePushNotify	Phone push on a structure break, default `false`.	off
EnableEmail	Mail delivery on a structure break, default `false`.	off
EnableSound	Sound playback on a structure break, default `false`.	off
SoundFile	Wav clip for the structure alert, default `alert.wav`.	alert.wav

Settings that fit your chart

Structure breaks need swings worth breaking. EURUSD H1 is the reference chart, where `FractalLookback` at `3` picks turns lasting a few hours. On M5 the memory fills with tiny swings and marks come thick. On H4 each break clears a level that took days to form.

When the Break of Structure Indicator fails

A three-bar fractal is a small swing, so many stored levels carry little weight.

One strong move can break several stored levels and produce a run of marks.

The memory has no age limit beyond its size cap, so a very old swing still counts.

Copy the compiled Break of Structure Indicator file into your MQL4/Indicators folder, and the MT5 build into MQL5/Indicators, then restart the terminal and drag it onto a chart. The step-by-step guide with screenshots is at how to install MT4 and MT5 indicators.

Background reading on the method behind the Break of Structure Indicator: Smart money index on Wikipedia, Chaikin Money Flow Cmf at StockCharts ChartSchool.

Download the Break of Structure Indicator for MT4 and MT5

The zip holds the compiled Break of Structure Indicator build for MT4 and MT5, plus a short README. Compiled files only, no source. Enter your email below and the download link arrives in your inbox.

FAQ

What does MaxSwingsToTrack at 50 hold?

The fifty most recent confirmed swings on each side, with their prices and bar times. Once the list is full the oldest entries fall out. Raising it means older levels stay eligible for a break, which produces more marks on a long chart.

How small a swing does FractalLookback accept?

One with three bars on each side that fail to beat it. That is a small window, so plenty of minor turns qualify. Raise it to 5 or more when the memory keeps filling with levels you would not have drawn yourself.

What do the DrawBoSLines objects show?

The exact price of the swing that broke, drawn as a dotted line in the bull or bear colour. They matter because a mark alone does not tell you which level gave way. `MaxBoSLines` `20` caps how many stay on screen.

Why does MaxSwingsToTrack store times, not indexes?

So the code cannot break a level that formed after the bar being tested. Bar indexes shift as new candles arrive, while a bar time never changes. Comparing times keeps the memory correct through history rebuilds.

Are results guaranteed?

No. Trading involves risk. Results are not guaranteed; past performance is not indicative of future results. Use the Break of Structure Indicator as one input. Always backtest before trading live.