# New Day Opening Gap

A Smart Money Concepts / ICT concept (Imbalance taxonomy) in the LuxAlgo Library, with 1 indicator implementation.

## What is a New Day Opening Gap?

A new day opening gap (NDOG) is the span between one trading day's closing print and the next day's opening print. The concept is cleanest on CME index futures, where the day genuinely stops: the session closes at 5:00 PM New York time, halts for an hour, and reopens at 6:00 PM. The NDOG is whatever distance separates those two prints. Even when the gap is only a few ticks, ICT practice marks its high, low, and midpoint and keeps them on the chart as reference levels for the coming session.

The logic mirrors other imbalances: nothing traded between the close and the reopen, so the gap is an unauctioned span the market may later rebalance, a scaled-down cousin of the classic session [opening gap](https://www.luxalgo.com/library/concept/opening-gap/) and of its weekly counterpart, the [new week opening gap](https://www.luxalgo.com/library/concept/new-week-opening-gap/). Reactions at recent NDOG levels are common enough to be worth charting but are not guaranteed, and small gaps in particular are often consumed within the first session and lose relevance quickly.

Within the ICT inventory the NDOG is the clock-defined member of the gap family. A [fair value gap](https://www.luxalgo.com/library/concept/fair-value-gap/) can print anywhere a three-candle imbalance forms; the NDOG forms at one fixed time per day, exists on every day the market halts, and needs no pattern recognition, just the two prints. The same tooling that tracks these gaps often derives extra reference levels from them: LuxAlgo's ICT NWOG/NDOG & EHPDA study, for example, computes event-horizon levels between retained opening gaps, an indicator construct from ICT-derived teaching that treats the space between gaps as structured rather than empty.

The working rhythm is short. An NDOG is marked at the 6:00 PM reopen, matters most during the overnight and the next regular session, and is usually consumed or forgotten within a day or two, which is why practitioners keep only the most recent few. Whether the reopen trades away from the gap or immediately rebalances it is itself information: holding cleanly above or below a fresh NDOG frames early bias, while an instant fill-and-reject says the halt repricing had no conviction behind it.

## How to identify a new day opening gap

The construction is mechanical; the judgment is in which gaps deserve to stay on the chart.

1. Chart the instrument in New York time so the daily halt is visible: on CME index futures, the 5:00 PM close and 6:00 PM reopen.
2. Mark the closing print and the reopening print, and box the span between them; that box is the NDOG, however small.
3. Add the three working levels: gap high, gap low, and the midpoint, the consequent encroachment.
4. Retain only recent gaps, typically the last few days, since NDOGs are consumed quickly and stale ones mostly clutter the map.
5. Watch the first interaction, ideally during active [killzones](https://www.luxalgo.com/library/concept/killzones/): rejection at the gap's edge or midpoint frames fades, while acceptance through it supports continuation.

## How traders use it

- As intraday reference levels: the gap's high, low, and midpoint (its [consequent encroachment](https://www.luxalgo.com/library/concept/consequent-encroachment/)) act as decision prices: acceptance through them supports continuation, rejection at them frames fades.
- As confluence: an NDOG overlapping another array (an imbalance, an order block, a session extreme) upgrades that level; a lone, stale NDOG is weak evidence on its own.
- As an early-session magnet: when price opens away from a fresh NDOG, trading back to rebalance it is a common opening scenario, planned as a possibility rather than assumed.
- Paired with liquidity logic: a sweep of [session liquidity](https://www.luxalgo.com/library/concept/session-liquidity/) that then rebalances into a fresh NDOG is a recognizable sequence, the gap supplying the destination after the stop run supplies the fuel.
- As a bias anchor at the reopen: holding above a fresh NDOG through the evening session leans bullish for the coming day within the ICT [time-anchor](https://www.luxalgo.com/library/concept/ict-time-anchors/) framework, while acceptance back through it unwinds that read.

## NDOG vs related gap concepts

- **Fair Value Gap** (https://www.luxalgo.com/library/concept/fair-value-gap/): An FVG is a three-candle imbalance that can print at any time and needs pattern recognition; the NDOG is defined purely by the clock and exists on every halted day. Both are marked with high, low, and midpoint and treated as candidates for rebalance.
- **Opening Gap** (https://www.luxalgo.com/library/concept/opening-gap/): The classic opening gap lives on regular-session equity charts, where overnight news creates large spans with well-studied gap-and-go and gap-fill behavior. The NDOG is its futures-native, often tick-sized cousin, valued as a reference level rather than a statistical fill bet.
- **New Week Opening Gap** (https://www.luxalgo.com/library/concept/new-week-opening-gap/): Same construction across a longer halt: Friday's close into the Sunday reopen. NWOGs form weekly, are conventionally retained five deep, and stay relevant for weeks; NDOGs form daily and usually die within a session or two. Scale and lifespan, not logic, separate them.

## FAQ

### What is the difference between NDOG and NWOG?

Scale and lifespan. The NDOG forms across the daily 5:00–6:00 PM New York halt (Monday through Thursday closes into the same evening's reopen) and matters mostly for the next session or two. The new week opening gap forms once a week, between Friday's close and Sunday's reopen, and is typically kept on the chart far longer; a common convention tracks the last five. Both are marked the same way: high, low, midpoint.

### Do NDOGs exist on forex and crypto?

Only where trading actually pauses. Crypto trades continuously, so there is no daily closing print and no true NDOG. In spot forex, liquidity thins sharply at the 5:00 PM New York rollover and many venues pause briefly, producing small gaps that some traders mark cautiously. The concept is cleanest on CME futures, where a genuine one-hour halt separates each day's close from the next open.

### Why mark a gap that is only a few ticks wide?

Because the span is unauctioned regardless of size: no trade occurred between those two prints, and ICT practice treats every such span as a potential rebalance reference. Small gaps are admittedly consumed fast, often in the first minutes, so their value is concentrated at the reopen and fades quickly. The midpoint read matters more on wider gaps where the halves genuinely differ.

### How long should NDOG levels stay on the chart?

The working convention is short: the current gap plus at most a few recent ones. An NDOG that has been traded through is rebalanced and retired, and even untouched ones lose meaning as the sessions that created them recede. This is the opposite of the NWOG convention, where five weeks of gaps are deliberately retained; daily gaps are simply a faster-decaying reference.

### What is EHPDA in NDOG and NWOG indicators?

Event Horizon PD Arrays, a construct from ICT-derived tooling implemented in studies like LuxAlgo's gap tracker. The indicator computes intermediate levels between neighboring retained opening gaps and treats them as interim reaction prices, on the idea that the space between gap references is structured. It is an indicator-level convention rather than a classical charting concept, so test its levels the way you would any derived line.

### Are NDOG reactions statistically reliable?

No audited public statistics support a firm reliability number, and the honest framing is the same as for other reference levels: recent NDOGs draw reactions often enough to be worth marking, small ones get consumed routinely, and confluence with other structure does the real sorting. Plan around the level with defined invalidation instead of assuming the gap owes you a fill or a bounce.

## Implementations in the Library

- ICT NWOG/NDOG & EHPDA (LuxAlgo): https://www.luxalgo.com/library/indicator/ict-nwog-ndog-ehpda/

## Related concepts

- Fair Value Gap: https://www.luxalgo.com/library/concept/fair-value-gap/
- FVG Behavior Rules: https://www.luxalgo.com/library/concept/fvg-behavior-rules/
- Inversion FVG: https://www.luxalgo.com/library/concept/inversion-fvg/
- Immediate Rebalance: https://www.luxalgo.com/library/concept/immediate-rebalance/
- Balanced Price Range: https://www.luxalgo.com/library/concept/balanced-price-range/
- Implied FVG: https://www.luxalgo.com/library/concept/implied-fvg/
- Volume Imbalance: https://www.luxalgo.com/library/concept/volume-imbalance/
- Opening Gap: https://www.luxalgo.com/library/concept/opening-gap/
- New Week Opening Gap: https://www.luxalgo.com/library/concept/new-week-opening-gap/
- Consequent Encroachment: https://www.luxalgo.com/library/concept/consequent-encroachment/

---

Source: https://www.luxalgo.com/library/concept/new-day-opening-gap/ (LuxAlgo Library, the encyclopedia of trading & technical analysis). Free to use with attribution: https://www.luxalgo.com/library/license/