Glossary
What Is the Difference Between BOS and CHoCH
A close beyond the last swing in the trend's direction: above the high in an uptrend, below the low in a downtrend. A BOS confirms the direction continues. The first close against the trend beyond the last significant swing: in an uptrend, below the last HL. It signals a possible change, not a finished reversal.
How it works
A BOS happens when price, moving with the trend, breaks the prior significant high in an uptrend or low in a downtrend, confirming the structure hasn't changed. As long as each new extreme forms in the trend's direction, that's a BOS, not a signal to look for a reversal.
A CHoCH is the opposite: the first break of structure against the current trend's direction — for example, breaking the last higher low in an uptrend. That specific break is usually treated as the first structural hint of a trend change, unlike an ordinary BOS.
Different chart-marking schools often use CHoCH as a synonym for MSS (market structure shift) — both describe the same first break against the trend. The difference is mostly terminology, not the mechanics of the signal itself.
Example
In an uptrend, price makes highs at 100, 104, and 108, and lows at 95, 99, and 103. A break above 108 to 111 is a BOS — the trend continues. Price then drops below 103 (the last higher low) to 101 — that's a CHoCH, the first break against the uptrend.
Common mistake
A common mistake is labeling any noticeable level break a BOS, and any pullback a CHoCH, without first marking the actual swing sequence of the current trend. Without that, both terms become arbitrary labels.
Read next
Related terms
Frequently asked questions
- How is BOS different from CHoCH?
- BOS confirms trend continuation with a break in the trend's direction, while CHoCH is the first structure break against the trend — a potential sign it's changing.
- How do you identify BOS and CHoCH on a chart?
- First mark the current trend's swing sequence, then watch which way price closes beyond the last significant extreme: with the trend, it's a BOS; against it, a CHoCH.
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