Break of structure (BOS): what it is and how to spot it

A break of structure is one of the first things traders learn to read on a chart. It tells you that price has taken out a swing that mattered and that the current trend is still in force. This guide covers what a BOS is, how to mark one, how break of structure trading works, and how to avoid the common false signals. At the end you can see the latest BOS events across eight coins.

What is a break of structure in trading?

A break of structure, or BOS, is when price closes beyond the most recent swing point in the direction of the existing trend. Swing points are the highs and lows that define market structure.

In an uptrend, price makes higher highs and higher lows. When it closes above the last swing high, that is a bullish BOS. In a downtrend, price makes lower highs and lower lows. When it closes below the last swing low, that is a bearish BOS.

The key word is direction. A BOS goes with the trend. A break against the trend is a different event, called a change of character.

How to identify a break of structure

1. Find the trend. Label the last few swings as HH and HL (up) or LH and LL (down).
2. Mark the last swing. In an uptrend, that is the last swing high. In a downtrend, the last swing low.
3. Wait for a close. The candle must close beyond the level. A wick alone is not a BOS by our rule.
4. Note the new swing. After the break, the next pullback usually forms the next higher low (up) or lower high (down). That is the new level to watch.

Our engine applies the same steps in code, then tags each event with a scope: internal for smaller swings inside the range, external for major swings. See the methodology.

Bullish and bearish BOS

• Bullish BOS: price closes above the last swing high. Buyers kept the higher-high pattern going.
• Bearish BOS: price closes below the last swing low. Sellers kept the lower-low pattern going.

On a chart, a BOS is shown as a line from the broken swing to the candle that closed beyond it. On our coin pages it appears as a diamond marker with the level in the events table.

Break of structure trading: how traders use it

Break of structure trading is about continuation. A typical process:

• Confirm the bias. A BOS in the direction of the higher-timeframe bias carries more weight than one against it.
• Wait for the pullback. After a bullish BOS, many traders wait for price to come back toward the broken level or the new higher low, rather than entering at the break.
• Define the stop. The idea fails if price takes out the swing that caused the break. Place the stop beyond it, with room for ATR noise.
• Size the trade. Use the position size calculator to risk a fixed percent.

None of this predicts what price does next. A BOS is a fact about the past, and trends can end right after one.

Break of structure examples

Examples help because the pattern looks simple in a textbook and messy on a real chart.

Bullish example, as a sequence. Price makes a HL, then rallies and closes above the last swing high. That close is the bullish BOS. Price then pulls back, holds above the old high, and forms a new HL.

Bearish example, as a sequence. Price makes a LH, then drops and closes below the last swing low. That close is the bearish BOS. Price bounces, stalls below the old low, and forms a new LH.

For real examples, see the live table below. It lists the latest BOS events our engine found on each coin, with the level and when it happened. Open any row to see it on the chart.

BOS vs CHOCH

BOS and CHOCH both break a swing. The difference is the direction compared with the trend. A BOS goes with the trend. A CHOCH is the first break against it. A table and examples are in the change of character guide.