Break of Structure (BOS)
BOS commonly refers to price breaking a significant prior swing in the direction of the existing structure—for example, an uptrend breaking above a prior swing high.
Different methodologies may require a wick, candle close or additional confirmation.
Change of Character (CHoCH)
CHoCH is commonly used for an early structural break against the previously established direction—for example, an uptrend breaking below a swing low considered structurally important.
Why definitions matter
BOS and CHoCH are not universally standardized technical indicators. The swing-selection and confirmation rules must be defined before they can be tested objectively.
Two traders can label the same chart differently if they use different swing definitions. Define the rules rather than relying only on the label.
Structure is hierarchical
A lower-timeframe CHoCH can occur while higher-timeframe structure remains unchanged. This makes timeframe explicitness important.
Common mistakes
Labeling after the outcome is known
Hindsight makes structural labels appear cleaner than real-time decisions.
Using every tiny swing
The result can become excessively sensitive and inconsistent.
Assuming CHoCH guarantees reversal
An early counter-structure break can fail.
BOS and CHoCH are practitioner terminology
Break of Structure and Change of Character are widely used chart-analysis labels, particularly in discretionary market-structure frameworks, but their definitions are not standardized across all traders or platforms.
One method may require a candle close through a swing, while another may count a wick or use a different swing hierarchy.
Turn the labels into testable rules
A systematic definition should specify how swings are identified, whether a wick or close is required, the minimum break distance and which timeframe controls the structure.
Without those rules, historical BOS and CHoCH labels can be changed subjectively after the outcome is already known.
A structural break describes what happened—not what must happen next
Breaking a previously defined swing shows that price moved beyond that structural reference. Whether the move continues depends on subsequent trading.
A CHoCH label can be treated as evidence that prior behavior has changed under the chosen framework, but not as proof of a complete trend reversal.
BOS and CHoCH can be useful organizational concepts when precisely defined, but the labels themselves do not create predictive certainty.
Key takeaways
- BOS commonly describes continuation through prior structure.
- CHoCH commonly describes an early break against prior structure.
- The terms are not universally standardized.
- Swing and confirmation rules must be explicit for objective testing.
Sources & further reading
This lesson is educational material. Market structure, exchange rules, fees, margin requirements and derivatives mechanics can differ by venue and can change over time. Verify current rules with the venue you use.