Market Structure from Pullback Swings — BOS, CHoCH, IDM - indicator for MetaTrader 5

My previous CodeBase entry, SMC Pullback Indicator, answered one question: which highs and lows actually matter? It stopped there deliberately, and the description said as much — no HH/HL labels, no BoS, no CHoCH, no IDM. Those are separate steps that need a reliable set of swings first.

This indicator is that next step. It marks market structure the way Smart Money Concepts (SMC) describes it, and it takes the same pullback detector — the class is included here unchanged, so the file stands alone with no dependency to install — and builds market structure on top of it: a trend, one live high, one live low, and the four events that move them. BoS, CHoCH, IDM and the liquidity sweep marked x.

What you see on the chart

Each event line is horizontal and spans from the bar that set the level to the bar that took it, so the length of the line tells you how long that level survived.

Layer one: the pullback swings

Briefly, because it is documented in full in the previous entry: a high becomes a swing only once price trades back through the low of the candle that made it. Nothing is decided by shape — a swing is an event, not a geometry, and that is what lets it carry a timestamp.

Two properties of that layer matter downstream:

• The output strictly alternates high, low, high, low. Never two highs in a row.
• A swing is confirmed later than the candle it sits on. The structure layer only ever sees a pullback once it is final, which is why the structure can never be built on a swing that is still provisional.

Both layers are driven one closed bar at a time, pullback first, structure second — so when the structure evaluates a bar, it already knows about any swing confirmed on that same bar.

Layer two: the structure

The structure holds exactly three things:

It is seeded from the first pullback high and the first pullback low, with the trend set to None. From that moment on, the pullback layer never writes into the structure again — it only supplies the reference levels described further down.

The break rule: close takes, wick sweeps

This single distinction produces three of the four event types:

So for every closed candle, with the trend and the two levels as they stand:

So BoS and CHoCH are the same event — a close through a level. The only thing that decides the label is whether the break agrees with the trend that is already in force. With no trend yet, the first break is a BoS by definition, because there is no character to change.

The sweep: when a wick becomes an x

A wick through a level is not an event on its own. It is recorded and left pending, because at that moment it is ambiguous — price may simply close through the level on the next candle, in which case it was an ordinary break in the making, not a sweep.

It becomes an x only when the next break happens on the opposite side. The classic sequence, in an uptrend:

1. Price runs above the structure high with a wick, but closes back below it. Recorded as a sweep candidate. Nothing on the chart.
2. Price turns and closes below the structure low.
3. That resolves the ambiguity. The move up was a liquidity grab, so the indicator moves the structure high onto the swept candle — the marker and both zig-zag legs follow it — draws the solid x line, and only then records the CHoCH.

Moving the high is the point of the whole exercise. The swing that the reversal started from is the sweep candle, not the older high that it ran through, and every level you derive afterwards should be measured from there.

The x line spans from the bar that set the level to the bar whose wick took it, drawn at the old level's price — that is the liquidity that was resting there. The bearish case is the exact mirror: a wick below the structure low, then a close above the structure high.

Three rules keep this honest:

• If several candles wick through the level, the furthest one wins.
• If price later closes through the level in the same direction, that is an ordinary break and the sweep candidate is discarded.
• A sweep candidate is discarded as soon as any new structure point is published. Once the structure has moved on, an older wick is stale and must not retroactively relocate a point.

IDM: confirming the new extreme

A break answers one question and opens another. When price closes above the structure high in an uptrend, you know a BoS happened — but you do not yet know where the new high is. Price is still moving. Calling the breaking candle the new high would be wrong the moment the next candle goes higher.

The inducement is the answer. At the moment of the BoS:

1. The latest pullback low becomes the reference — the IDM.
2. Price continues up; the indicator tracks the highest high it reaches, but publishes nothing.
3. Each time a new pullback low forms above the current IDM, the IDM ratchets up to it. The reference is always the highest pullback low seen since the break.
4. When price finally comes back and takes the IDM, the new structure high is confirmed: it is the highest high between the breaking candle and the candle that took the IDM.

At that moment the dotted IDM line is drawn — from the pullback that set it, across to the candle that ran through it — and the structure high marker appears. The two always come together, which makes the IDM line a useful audit of the logic: every structure high should have an IDM line ending on the bar where its marker appears.

The bearish case is the mirror: after a bearish break the IDM is the lowest pullback high, and taking it confirms the new structure low as the lowest low of the move.

Keeping the chain a zig-zag

Structure points must alternate, exactly like the pullback layer. Two highs in a row is a broken chain, not a structure.

A bullish break is on its way to publishing a high. If the newest point in the chain is already a high, a low is missing between them, so the indicator takes the lowest low between that high and the breaking candle and publishes it first. If the newest point is already a low, the chain alternates and nothing is inserted.

That one rule covers every case: your BoS in an established trend, your CHoCH, and the very first break after the seed. The bearish case is the mirror — the highest high of the swept range.

Edge cases, stated openly

On repainting — read this before using it

The pullback layer does not repaint, and nothing has changed about it.

The structure layer does, and it is not a defect — it is what the method is. Two things move:

• A pending extreme moves as price extends, right up until the IDM is taken. It is published live so you can see the structure forming, instead of waiting in the dark.
• A sweep relocates a point backwards, by design. That is the whole purpose of the x.

Once an extreme is confirmed by its IDM and no sweep is pending against it, it is settled. Events — BoS, CHoCH, x, IDM — are append-only and never move.

Inputs

Pullback layer

Market structure

There is no period, depth or sensitivity setting anywhere — the structure has no parameters of its own. If you want larger structure, raise the timeframe or switch the pullback rule to Close.

Display

Alerts

Popup and push notification on a structure event. They fire only on live updates, never while history loads, and only once per event.

Using it from an EA

Five buffers. The empty value is 0.0.

int h = iCustom(_Symbol, _Period, "SMC_MarketStructure");
double trend[];
CopyBuffer(h, 2, 0, 1, trend);   // 1 = up, -1 = down, 0 = none

Buffer 2 is filled on every bar including the forming one, so reading it at shift 0 always returns the current trend. The other four are sparse by nature.

Both engines are self-contained classes with no buffer or chart dependencies — CPullbackDetector takes price arrays and reports confirmed swings, CMarketStructure takes bars plus those swings and reports a point chain and an event list. Both can be copied straight into an EA if you would rather not go through iCustom, which also gives you the events — they are not exposed through buffers.

What it deliberately does not do

It stops at structure. No order blocks, no fair value gaps, no premium/discount zones, no entries and no HH/HL/LH/LL labelling. Those all need a dependable trend and a dependable pair of levels first — which is what this provides, with every decision it makes visible on the chart as a line you can check.