Field notes · 2026-05-03
Gap Types That Matter Before the Open
Gap analysis in our clinic is not a catalogue of textbook names. We care about how the gap sits relative to the prior close and the coming opening range. A full overnight gap that leaves a clear void asks different questions than a partial gap that overlaps the prior session's last hour.
Before the open we ask students to classify the gap in one sentence: away from prior value, into prior value, or overlapping the prior opening range itself. That single sentence changes whether they expect fill pressure, continuation, or a quiet drift into a new box.
We also measure the gap in points and as a fraction of the prior day's true range. Large gaps that open into thin liquidity often produce violent first prints; those prints can define an unreliable range if you freeze the box too early.
Bring five gaps you have already watched live to the next Gap Analysis Clinic. We will re-mark them together and attach each to an opening-range decision rather than leaving them as decorative history.