Break of Structure (BOS)

In an uptrend defined by higher highs and higher lows, a break of structure is price closing above the latest confirmed swing high: the trend doing exactly what trends do, again. In a downtrend, it's the break below the latest swing low.

Wick or close?

The most consequential detail in any BOS rule is whether a wick through the level counts, or only a close beyond it. Wick-based breaks trigger earlier and include every stop-hunt. Close-based breaks are cleaner and later. Neither is "correct", but a systematic strategy has to pick one and apply it identically everywhere, which is where hand-drawn structure analysis and backtestable rules part ways.

How it's traded

The continuation entry takes the BOS itself, with a stop below the swing that launched the breaking move. Structurally this is a Donchian breakout with swing-defined rather than fixed-window levels. The pullback entry waits for the BOS, then buys the retrace toward the broken level, treating the old resistance as new support.

The opposite event, breaking a swing against the trend, is not a BOS but a change of character, and it means something quite different.

On AlphaProve

The wick-versus-close decision this page hangs on has a natural default here: the engine decides on bar close and fills on the next 1-minute open, so a rule comparing price to the last swing high is close-based unless you deliberately test the level intrabar. ctx.indicators.williams_fractals supplies the swing extreme the break is measured against, and a Python strategy can return a Signal whose stop_loss sits at the swing that launched the move — the below-the-swing stop described here, expressed as a per-trade bracket. That makes the Donchian breakout framing testable with swing-defined levels rather than a fixed window.