Market Structure Shift (MSS / BOS / ChoCh)
The moment price breaks its pattern of higher-lows or lower-highs, signaling a possible trend change.
What it is
Markets trend in swings: higher highs and higher lows, or lower highs and lower lows. A market structure shift (also called break of structure or change of character) happens when that sequence breaks: for example, price takes out the last higher low with displacement, suggesting sellers have taken control.
Why it matters
Structure defines bias. Trading with the current structure, and flipping bias only when it genuinely shifts, keeps your bias tied to what price has actually done.
NQ example ILLUSTRATION
NQ has printed higher lows all morning. At 1:15pm it breaks the latest higher low with a 40-point displacement candle. Structure has shifted, and a long bias no longer matches what price is doing.