Opening Gap

What is an Opening Gap?

An opening gap is the span between one session's close and the next session's open, untraded not because price moved too fast, but because the market was shut. That makes it a calendar-made imbalance, unlike a fair value gap, which needs a fast three-candle sequence to form. ICT's taxonomy names the recurring ones: the new day opening gap (NDOG) between a futures session's close and its reopen, the new week opening gap (NWOG) between Friday's close and the weekly reopen, and the opening range gap between the prior regular-session close and the next 9:30 AM ET open on U.S. index products.

Gap analysis long predates the SMC vocabulary: Edwards and Magee's Technical Analysis of Stock Trends (1948) sorted gaps into common, breakaway, runaway, and exhaustion types and debated which fill. Michael J. Huddleston's ICT teaching recast the idea in imbalance terms: a gap is a range where no trade occurred, a candidate destination for future price like any other imbalance. For the opening range gap specifically the anchor is regular-session prices: index futures trade nearly around the clock, so that gap is an imbalance in regular-hours terms, not a literal untraded hole.

The SMC/ICT reading treats each gap as unfinished business: a range holding no agreed prices, which the market often revisits: fully, partway to the midpoint (consequent encroachment, in ICT vocabulary), or not at all. Recent gaps, weekly ones especially, stay marked on the chart and are watched as reference levels long after the open that created them.

Because the levels are known before the bell, gaps slot into session planning alongside other pre-marked references: edges and midpoint are watched with session liquidity such as the overnight high and low, and reactions are timed against the morning killzones. A gap edge can also act as inducement, since a poke through it that instantly fails is a familiar trap before the real move.

How to mark opening gaps on a chart

The levels are objective; the work is picking the right closes for your product and keeping the boxes current.

1. 1Define the reference closes: the daily close at the CME maintenance break for a new day gap, Friday's close for a new week gap, and the prior regular-session close (4:00 or 4:15 PM ET by convention) for the opening range gap on index futures.
2. 2At each open, draw a box from the reference close to the opening print and add the midpoint line, the level ICT calls consequent encroachment.
3. 3Keep recent weekly gaps on the chart, commonly the last five, since old unfilled gaps keep drawing reactions weeks later.
4. 4At the open, watch the first reaction: fill attempt, rejection at an edge, or hesitation at the midpoint, and let that pick the scenario you trade.

How traders use it

• As pre-marked session levels: the gap's high, low, and midpoint are mapped before the open, and the first reactions at those levels (rejection at an edge, hesitation at the midpoint) frame early trades.
• As fill scenarios rather than predictions: some gaps fill immediately, some reach the midpoint and continue, some stay open for weeks. The useful posture is a branch plan for each outcome, not an assumption that the fill is owed.
• As longer-term reference zones, several recent weekly gaps are commonly kept on the chart, and price returning into an old one is watched for support or resistance behavior: a tendency to plan around, not a rule.
• As a morning bias filter: whether the first half hour holds price beyond the gap or rejects it back inside is an early tell; some traders map the session onto the accumulation-manipulation-distribution template with the gap-fill leg as the manipulation.
• As confluence with other imbalances: a gap edge overlapping an order block or old session extreme is an upgraded level, and traders who formalize imbalance treatment apply their FVG behavior playbook to gap boxes.

Opening gap vs related concepts