Break of Structure (BOS)

A break of structure is a continuation event. In an uptrend, price closes or trades beyond the last higher high. In a downtrend, it breaks the last lower low. The trend has extended. The term is used in price-action and smart-money writing. It is the same price fact either way: a prior swing extreme gave way in the direction already in force. This entry is shared with the market-structure category. The meaning does not change there.

Mark the last confirmed swing high in an uptrend, or swing low in a downtrend. A BOS is a break of that point, not a break of a moving average and not a break of a trendline. Decide in advance whether a wick counts or only a close.

An upside BOS says buyers took the prior high. Trend followers treat pullbacks after a BOS as continuations, with risk under the swing that launched the break.

A downside BOS says sellers took the prior low. It confirms the downtrend. It is not, by itself, a reversal. A reversal through the opposite swing is a change of character.

Calling every tick through a high a BOS on a timeframe where that high was not a swing. Also calling a countertrend break a BOS when it is really the first sign of a character change. Keep the two words apart.

BOS labels are everywhere on social charts because any high can be called a swing. If you did not mark the swing before it broke, the label is hindsight.