Break of Structure is the Smart Money Concepts term for what traditional technical analysis calls trend confirmation — when price breaks beyond the previous swing high (in an uptrend) or below the previous swing low (in a downtrend), confirming that the trend is continuing. The concept is not new — Dow Theory in 1902 described the same principle. What SMC adds is the integration of BOS with order blocks, FVGs, and liquidity concepts — creating a complete framework for reading price structure through an institutional lens. Understanding BOS precisely is the foundation of that framework.
What Is Market Structure?
Market structure is the pattern formed by the sequence of swing highs and swing lows on a chart. An uptrend has higher highs and higher lows — each new peak is above the previous peak, and each pullback low is above the previous pullback low. A downtrend has lower lows and lower highs — each new trough is below the previous, and each rally high is below the previous. A range has neither — highs and lows oscillate without consistent direction.
In SMC terminology, these highs and lows are referred to as Higher Highs (HH), Higher Lows (HL), Lower Highs (LH), and Lower Lows (LL). The sequence of these labels tells you the market structure: HH-HL sequence = uptrend, LL-LH sequence = downtrend, alternating = range.
Defining BOS
A Break of Structure (BOS) occurs when price breaks and closes beyond a significant structural level in the direction of the current trend. In an uptrend, a BOS is confirmed when price closes above the previous Higher High — the most recent swing high that has been established. In a downtrend, a BOS is confirmed when price closes below the previous Lower Low.
The critical word is closes. A wick through a structural level is not a BOS — it may be a liquidity grab. A candle body closing beyond the structural level is the confirmation. This distinction prevents confusing temporary spikes with genuine structural breaks.
Bullish BOS
A bullish Break of Structure occurs in the context of an uptrend. Price has been making Higher Highs and Higher Lows. The most recent swing high is established at level X. When price subsequently rises and closes above level X, a bullish BOS is confirmed — the uptrend continues and a new Higher High has been established.
Swing Low 1: 1.0600 (LL) Swing High 1: 1.0800 (HH) Swing Low 2: 1.0700 (HL — higher than 1.0600) Price rallies from 1.0700. Closes above 1.0800 (Swing High 1). BULLISH BOS CONFIRMED at 1.0800. Previous HH has been exceeded. New HH established. Uptrend structure is intact. Swing High 2: wherever this impulse stops. (New HH to be established.) Post-BOS expectation: Price pulls back to form HL. HL becomes a potential entry for the next bullish leg. Order block from the BOS impulse provides the re-entry zone.
Bearish BOS
A bearish Break of Structure occurs in a downtrend. The most recent swing low is established at level Y. When price falls and closes below level Y, a bearish BOS is confirmed — the downtrend continues and a new Lower Low is established.
Swing High 1: 1.2800 (HH prior uptrend) Swing Low 1: 1.2600 (LL) Swing High 2: 1.2720 (LH — lower than 1.2800) Swing Low 2: 1.2550 (LL — lower than 1.2600) After Swing Low 2, price rallies to 1.2680 forming a new LH. Then price falls and closes below 1.2550 (Swing Low 2). BEARISH BOS CONFIRMED at 1.2550. New LL established. Downtrend continues. Post-BOS expectation: Price pulls back toward LH zone. The bearish order block from the BOS impulse provides a short entry zone.
BOS as a Trend Confirmation Tool
BOS is used in SMC as the primary trend confirmation and continuation tool. A confirmed BOS tells you that institutional momentum is intact in the trend direction and that pullbacks to order blocks or FVGs left by the BOS impulse are high-quality re-entry opportunities.
The relationship between BOS and order blocks is the core practical application: the impulse that creates the BOS leaves behind an order block (the last candle before the impulse in the opposite direction) and often creates an FVG within the impulse itself. When price pulls back after the BOS and enters the order block or FVG zone, that pullback into the institutional order zone in the direction of the confirmed trend is the BOS re-entry trade.
BOS is trend confirmation — not a trade entry signal in itself. The entry comes after the BOS, on the pullback to the order block or FVG created by the BOS impulse. Entering at the BOS level itself means buying into a new high or selling into a new low — typically not the best risk-reward positioning. Wait for the pullback.