What Is a Break of Structure (BOS) in Trading?

A break of structure (BOS) happens when price closes beyond a prior significant swing high (in an uptrend) or swing low (in a downtrend), confirming that the existing trend is still in control. It's one of the core building blocks of Smart Money Concepts (SMC) trading, and it's what most other structural reads — order blocks, fair value gaps — are anchored to.

BOS vs. change of character (CHoCH)

A break of structure confirms trend continuation — an uptrend making a new higher high, or a downtrend making a new lower low. A change of character (CHoCH) is the opposite signal: price breaks structure in the direction against the prevailing trend, an early sign the trend itself may be shifting. Mixing these two up is one of the most common beginner errors in SMC trading — a BOS confirms what's already happening; a CHoCH questions it.

Why a close matters, not just a wick

Most SMC traders require a candle close beyond the prior swing point, not just a brief wick through it — a wick alone is closer to a liquidity sweep than a genuine structural break. This distinction is exactly why "a wick past the high" and "a break of structure" get confused so often.

How traders use it

• As confirmation to stay with an existing trend rather than fade it.
• As the anchor point for identifying the order block and fair value gap that preceded the break.
• Across multiple timeframes — a BOS on a higher timeframe carries more weight than one on a lower timeframe alone.

How Scan Mode reads this

Scan Mode's structure detection requires a genuine candle-close break, not a wick, before treating a move as a real break of structure — and multi-timeframe agreement on that break is one of the stronger contributors to the confidence score, alongside order blocks, fair value gaps and liquidity sweeps.

Educational content only. Not financial advice. Chart structure concepts do not guarantee any trading outcome.