Market Structure: BOS & CHOCH
Learn how to read institutional market structure using Break of Structure (BOS) and Change of Character (CHOCH) — the foundation of all Smart Money Concepts analysis.
Learn how to read institutional market structure using Break of Structure (BOS) and Change of Character (CHOCH) — the foundation of all Smart Money Concepts analysis.
Market structure is the language of price. Before order blocks, fair value gaps, or liquidity — before any other SMC concept — you must learn to read how price is structured in time.
The foundation is simple: price moves in waves. Each wave creates a swing high (a local peak) and a swing low (a local trough). The sequence of these waves tells you everything about who is in control of the market.
A swing high is a price peak where buying pressure momentarily exhausted itself and price reversed. A swing low is a trough where selling pressure reversed. These two points define the building blocks of all structure.
Conventional technical analysis labels these as "support" and "resistance." SMC goes deeper — it reads the sequence of these swing points to determine intent.
Bullish Structure (Uptrend) Price is making Higher Highs (HH) and Higher Lows (HL). Each successive peak is higher than the last. Each pullback ends higher than the prior trough. Buyers are in control.
Bearish Structure (Downtrend) Price is making Lower Highs (LH) and Lower Lows (LL). Each rally fails at a lower level. Each selloff reaches a lower trough. Sellers are in control.
Ranging / Consolidation Highs and lows are roughly equal — neither buyers nor sellers are gaining ground. The market is accumulating energy for its next directional move.
Ask Diplyzer:
"Identify all major swing highs and swing lows on [ticker] over the last 6 months on the daily chart. What is the current structural bias — bullish, bearish, or ranging?"
A Break of Structure occurs when price breaks beyond a prior significant swing point in the direction of the current trend. It confirms that the trend is intact and continuing.
Bullish BOS: Price breaks above a previous swing high → Buyers are maintaining control. The trend is confirmed bullish.
Bearish BOS: Price breaks below a previous swing low → Sellers are maintaining control. The trend is confirmed bearish.
The broken level does not disappear after a BOS — it often becomes a future support (after bullish BOS) or resistance (after bearish BOS) zone. Institutions that placed orders at that level either added to positions on the breakout or will defend that level if price returns.
Aggressive traders enter on the candle that breaks structure. Conservative traders wait for price to retest the broken level before entering:
Ask Diplyzer:
"Show me all Break of Structure events on [ticker] over the last 3 months on the 4-hour chart. Which broken levels have become active support or resistance zones?"
A Change of Character is the first BOS that goes against the current trend. It is the earliest warning signal that the prevailing structure may be shifting.
Bearish CHOCH: In an uptrend making higher highs and higher lows, price breaks below a previous swing low for the first time. Sellers have suddenly overcome buyers at a level they held before. The market is "changing character."
Bullish CHOCH: In a downtrend making lower highs and lower lows, price breaks above a previous swing high for the first time. Buyers have reclaimed a level sellers previously held.
| Event | Direction | Signal |
|---|---|---|
| BOS | Same as trend | Trend continuation |
| CHOCH | Against trend | Potential trend reversal |
A CHOCH is a warning, not a reversal confirmation. One CHOCH followed by a resumption of the original trend structure is common. Look for a CHOCH followed by:
Ask Diplyzer:
"Has [ticker] shown any Change of Character (CHOCH) signals in the last 6 weeks on the daily or 4-hour chart? Is there evidence the trend may be reversing?"
Professional SMC traders always analyze structure across multiple timeframes:
The rule: only take trades in alignment with the higher timeframe structural bias. If the weekly structure is bearish, you need strong reasons to be buying on the daily.
Ask Diplyzer:
"Give me a multi-timeframe market structure analysis for [ticker]: weekly, daily, and 4-hour. What is the structural bias at each timeframe and are they aligned?"
Market structure is the map. Everything else in SMC is built on top of it:
Complete structure + SMC analysis:
"Full multi-timeframe SMC analysis on [ticker]: swing structure on daily and 4-hour charts, all BOS and CHOCH events, active order blocks created by those structural moves, and any FVGs nearby."