Break of Structure (BOS) and Change of Character (CHoCH) in Trading

What is a break of structure (BOS) in trading?

Structure is the sequence of swing highs and swing lows on a chart. A swing high is a peak with lower highs on both sides; a swing low is a trough with higher lows on both sides. An uptrend makes higher highs (HH) and higher lows (HL); a downtrend makes lower highs (LH) and lower lows (LL).

A break of structure is price closing beyond the last swing in the direction the trend was already going. In an uptrend, a candle closes above the most recent swing high, so the chart has a new higher high. In a downtrend, a candle closes below the most recent swing low, a new lower low. Nothing about the trend has changed; the BOS is simply the moment the trend shows it is still working.

In the drawing at the top of the page, price rallies from $60.00 to $64.00 and pulls back to $62.00, a higher low. When a candle then closes above $64.00, that is the BOS. The old high becomes a reference level: many traders watch whether price holds above it on the next pullback.

Break of structure (BOS)

A candle close beyond the most recent swing in the direction of the trend: above the last swing high in an uptrend, below the last swing low in a downtrend. It is read as continuation.

What is a change of character (CHoCH)?

A change of character is the first break against the trend. In an uptrend, the swing that matters is the last higher low, the low from which price made its latest high. If a candle closes below it, the sequence of higher lows is broken: that is a CHoCH. In a downtrend, it is a close above the last lower high.

In the drawing at the top, after the BOS price runs to $67.00, pulls back to $65.00 (a new higher low) and rallies only to $66.40, a lower high. A candle then closes below $65.00: CHoCH. The drawing below shows the mirror image in a downtrend, where the BOS is a close below $76.00 and the CHoCH a close above $75.00.

Some teachers call the same event a market structure shift (MSS), and some keep that name for a break that comes with a fast, large move. The names are trader jargon, not a standard, so decide which definition you use and write it down.

Change of character (CHoCH)

The first candle close beyond a swing against the trend: below the last higher low in an uptrend, above the last lower high in a downtrend. It is a warning that the trend may be turning, not proof.

Market structure shift (MSS)

Another name some traders use for a change of character, sometimes kept for a break that comes with a fast, large move.

BOS vs CHoCH: continuation or possible reversal?

The two labels answer different questions. A BOS says the trend made progress. A CHoCH says the trend failed to protect its last swing, and its plain reading is “stop buying”, not “start selling”. It is the old Dow Theory idea, that an uptrend ends when its highs and lows stop rising, with newer labels attached. Neither label is a forecast:

• Direction: a BOS breaks with the trend; a CHoCH breaks against it.
• The level broken: a BOS breaks the last swing high in an uptrend (the last swing low in a downtrend); a CHoCH breaks the last higher low (the last lower high).
• What traders read into it: after a BOS, continuation, so they look for pullbacks in the trend’s direction. After a CHoCH, a warning, so they stop adding to the old trend.
• What it does not say: a BOS does not mean the next pullback will hold, and a CHoCH does not mean the trend has reversed. Price can go sideways or make a new high anyway.
• What comes next if the turn is real: a lower high and then a lower low, which is the new trend’s first BOS. The trend reversal guide covers that sequence.

Does a wick count, or only a candle close?

This is the question that changes the count most. Wicks poke through swing levels all the time, because resting stop orders cluster just beyond obvious highs and lows. If every poke counted, a chart would be covered in breaks that reversed within one candle.

The common convention, and the one this site uses in the market structure guide, is to mark the level at the wick, the true extreme of the swing, and to count a break only when a candle closes beyond it on your timeframe. A close shows that price was accepted past the level, at least for that candle.

Hypothetical, as in the drawing below: the last swing high is $64.00. A candle trades up to $64.25 and closes at $63.85. With a close rule, nothing broke; many traders would call that a possible liquidity sweep. Another candle closes at $64.30: that is the break. Some traders do count wicks, which gives earlier labels and more false ones. Either rule can be used; mixing them cannot.

How do you mark BOS and CHoCH step by step?

Labels drawn after the fact always look clean. To get labels you could have drawn live, fix the rules first and apply them from left to right, as in the steps below.

Remember that a swing is confirmed late: with a five-candle rule, a swing high exists only after two more candles have closed. TradingView’s help page says a fractal always lags by two or more candles. Scripts that print BOS and CHoCH labels inherit that lag, and some redraw; see TradingView repainting.

1. Choose one timeframe and one swing rule. A common rule is the five-candle swing: a high with two lower highs on each side, or a low with two higher lows on each side. TradingView’s built-in Williams Fractal indicator marks these.
2. Mark the last confirmed swing high and swing low, and state the trend: higher highs and higher lows, lower highs and lower lows, or neither.
3. In an uptrend, draw one line at the last swing high and one at the last higher low. In a downtrend, at the last swing low and the last lower high.
4. Wait for a candle to close beyond one of the two lines. A close beyond the trend-side line is a BOS; a close beyond the other line is a CHoCH.
5. After a BOS, wait for the pullback to print a new confirmed swing, then move the lines: the new high and the new higher low.
6. After a CHoCH, stop labeling the old trend. Wait for the next swing to see whether a new trend forms or price goes sideways.
7. If the swings overlap and neither side makes progress, label a range and mark nothing until a close leaves it.

A worked example with prices (hypothetical)

Hypothetical, on a 1-hour chart of a liquid stock, using the numbers in the drawing at the top. Price rallies from $60.00 to a swing high at $64.00, then pulls back to $62.00 and turns up: a higher low. The two lines are now $64.00 above and $62.00 below.

What each label was worth depends on what you did with it. A trader who bought the first pullback after the BOS, near $65.00 with a stop under that low, was stopped out for a planned loss when the CHoCH printed. A trader who treated the CHoCH as a sell signal had no setup yet: price could bounce from $63.80, hold above $62.00 and go sideways for days. The labels describe; the plan, the stop and the size still have to come from you. The market structure guide walks through a full pullback trade with its stop and size.

1. A candle trades up to $64.25 and closes at $63.85. Wick only: no label.
2. Two candles later, one closes at $64.30. BOS: the uptrend continues. The trend-side line will move to the next confirmed high.
3. Price runs to $67.00 and pulls back to $65.00, where it turns up again. $67.00 is the new swing high and $65.00 the new higher low; the lines move to those prices.
4. The next rally stalls at $66.40, below $67.00: a lower high. That alone is not a CHoCH, because no swing has been broken yet.
5. A candle closes at $64.70, below the $65.00 higher low. CHoCH: the first close against the trend. Price trades on down to $63.80.

False breaks and common mistakes

A break is only known to be false afterwards, and at first it looks exactly like a real one. The failures and mistakes that cost the most:

• The wick break: price trades beyond the swing and closes back inside. With a close rule it was never a break.
• The failed break: a candle closes beyond the level, and the next one or two close back inside. Treat it as a false breakout and expect the label to be wrong some of the time.
• Labeling every small swing. On a low timeframe almost any wiggle is a swing, and the chart fills with BOS and CHoCH tags that cancel out. Ignore swings smaller than the stock’s normal movement, for example about one average true range.
• Changing the rule mid-chart: counting a wick when it suits the trade you want and a close when it does not.
• Trading the label alone. A BOS in the middle of a range, far from any level and against the higher timeframe, is just a candle.
• Treating a CHoCH as a reversal. It marks one failed swing. Many trends print a CHoCH on a small chart and carry on.
• Chasing the break. Buying far above the broken level puts the stop far away and the target close.
• Trusting labels drawn in hindsight, including a script’s. They were placed with candles you would not have had.

Which timeframe should you use for BOS and CHoCH?

Structure is nested. A change of character on the 5-minute chart is often nothing more than a pullback inside the 1-hour trend, and a 1-hour CHoCH may be a pullback on the daily chart. The same candle can carry opposite labels depending on which swings you measure it against.

A practical approach is to read structure on a higher timeframe first, mark its last swing high and higher low, and use a lower timeframe only for timing, as the multi-timeframe analysis guide describes. Lower timeframes produce many more labels, and each one means less. Whatever pair you choose, write the timeframe on every label.

Do BOS and CHoCH work? What research can and cannot say

We are not aware of a published, peer-reviewed test of BOS and CHoCH labels as retail courses teach them, so treat any success rate you see quoted for them with suspicion. What exists is research on close relatives of the idea.

Brock, Lakonishok and LeBaron (1992) tested a trading-range break rule, buying when price exceeds a recent high, on the Dow Jones index from 1897 to 1986 and found that buy signals were followed by higher returns than sell signals. Sullivan, Timmermann and White then widened the test to thousands of rules and corrected for data snooping: the best rules did not hold up in the following ten years. Park and Irwin’s 2007 review counted 56 of 95 modern studies with positive results, and warned that many suffered from data snooping and rough cost estimates.

Lo, Mamaysky and Wang (2000) made a related point about method: chart patterns are often in the eye of the beholder until they are written as rules a computer can apply. That is the practical lesson here. BOS and CHoCH are useful as a fixed vocabulary for where a trend is and where it would be wrong, and only as good as the rules, risk control and testing around them. See does technical analysis work? for the full evidence.