A BOS (break of structure) is a break of a high or low in the direction of the current trend: it confirms continuation. A CHoCH (change of character) is the first break in the opposite direction: it signals the trend is being challenged, not yet that it has reversed. In both cases, the break is confirmed on a candle close, on the timeframe where you read structure.
Price has been making higher highs and higher lows all morning. At 9:40, an M5 candle drops below the last low. You call it a CHoCH and sell. Twenty minutes later, price is back above and heading higher. On the H1, nothing had happened: structure was intact, and you read a pullback as a reversal.
How do you map market structure?
By marking the significant highs and lows, the ones a move starts from. An uptrend chains higher highs (HH) and higher lows (HL). A downtrend chains lower highs (LH) and lower lows (LL).
The whole job is deciding which points count. Two common conventions:
- Simple swing points: a high with lower candles on each side (for example two on each side).
- Points that produced a break: only highs and lows that launched a move breaking prior structure.
The second gives fewer points and a steadier read. Pick one, write it down, keep it.
What is a BOS?
It is the break, on a close, of the last high in an uptrend (or the last low in a downtrend). It confirms the trend continues and creates a new reference: the low that launched the break becomes the last HL to watch.
The BOS is also what validates SMC zones: an order block only counts if the impulse leaving it breaks structure, and a fair value gap has more context when it is born from that impulse.
What is a CHoCH?
It is the first break against the trend. In an uptrend, the CHoCH is a close below the last HL, the one that launched the last higher high. The market just did something it had not done since the trend began.
A CHoCH does not say the trend has reversed. It says the sequence is broken. What follows decides: a lower high and then a new lower low, and the downtrend is in place. A move back above the last high, and the CHoCH was an accident.
Wick or close: when is a break valid?
On a close, on the timeframe where you read structure. A wick above a high that closes back below is not a BOS: it is a liquidity sweep, triggering stops above the high, and it can precede a move the other way.
| What price does | Reading |
|---|---|
| Wick beyond the level, close back inside | Sweep, no break |
| Body closes beyond the level | Break (BOS or CHoCH depending on direction) |
| Close beyond, then immediate return | Fragile break, needs confirmation |
How do you read BOS and CHoCH across timeframes?
Top down. The higher timeframe gives direction, the lower one gives the trigger.
| Higher timeframe (H4) | Entry timeframe (M15) | Usual reading |
|---|---|---|
| Bullish | Bullish BOS | Continuation, context favours longs |
| Bullish | Bearish CHoCH | Most often a pullback within the H4 trend |
| Bullish | Bullish CHoCH after a pullback | Possible trigger in the H4 direction |
| Bearish | Bullish CHoCH | Likely pullback, counter-trend long |
The third row is what many SMC traders look for: H4 bullish, M15 pulls back (bearish CHoCH), then M15 turns up and breaks its last high (bullish CHoCH), realigning with the H4.
A worked example
GBPUSD, bullish H4, structure read on the M15 (example levels):
| Step | Level | M15 reading |
|---|---|---|
| Last high of the trend | 1.2780 | HH |
| Pullback, close below the last HL at 1.2730 | 1.2722 | Bearish CHoCH: pullback in a bullish H4 |
| Pullback low | 1.2705 | New low |
| Bounce, close above the intermediate high at 1.2745 | 1.2751 | Bullish CHoCH: trigger |
| Return into the zone that launched the break | 1.2725 | Entry |
| Stop below the pullback low | 1.2698 | Risk: 27 pips |
| Target: last high | 1.2780 | 55 pips, about 2 R |
The trade is not taken on the first CHoCH, which goes against the H4. It is taken on the second, which puts the M15 back in line with the H4, on the return to the origin zone.
Log the break type on every trade →
Classic mistakes
Reading structure on too many points. On an M1, every wiggle becomes an HH or an LL. Structure changes every ten minutes and says nothing.
Confirming on wicks. The costliest one: wicks beyond an obvious high are exactly where stops get swept.
Treating every CHoCH as a reversal. Against the higher timeframe, most CHoCHs are pullbacks.
Switching conventions mid-way. If the reference low changes from chart to chart, you will always find a reading that agrees with your urge to trade.
The limits of BOS and CHoCH
- It is a reading grid, not a prediction. Structure describes what price did.
- New vocabulary, old idea. Higher highs and higher lows are Dow theory's definition of a trend. SMC adds validation and context rules.
- Ranges blur everything. In a trendless market, breaks alternate both ways.
This content is educational and is not investment advice. Trading involves a risk of capital loss.
Measuring your breaks on Trade Stack
On Trade Stack, add "BOS" and "CHoCH" to your Confluences in Settings and tick the right one on each trade. After 50 trades, the By setup view (Pro plan) shows which trigger actually has an edge, on your data rather than on a diagram.
Measure my breaks on Trade Stack
Key takeaways
- BOS: a break in the trend's direction, confirming continuation.
- CHoCH: the first break against the trend, challenging it without reversing it yet.
- A break is confirmed on a close on your reading timeframe. A wick that returns is a sweep.
- The higher timeframe gives direction: against it, a CHoCH is usually a pullback.
- Pick one swing-point convention and keep it on every trade.
Method: example levels built for illustration (GBPUSD, M15), unrelated to real prices. Ratio: (1.2780 − 1.2725) ÷ (1.2725 − 1.2698) = 55 ÷ 27 ≈ 2 R.
