Direct Answer
An NR4 bar is defined purely by comparison: take the high-low range of each of the last four daily bars, and if the most recent one is smaller than the other three, it qualifies as NR4. Unlike a candlestick shape such as a doji or a hammer, NR4 has no requirement about where the open and close sit within the bar, only that the bar's total range is unusually small relative to its own recent history.
Key Takeaways
- An NR4 bar is a daily bar whose high-low range is the narrowest of the past four trading days, a purely mechanical, rolling comparison, not a shape like a doji.
- It's read as a volatility-compression signal: a session where price traded unusually tightly relative to its own recent history, often watched ahead of a potential breakout.
- NR4 says nothing about direction on its own, it flags that a range has compressed, not which way price will eventually break.
- Most approaches wait for a confirmed close beyond the NR4 bar's high or low, rather than acting the instant that range narrows.
- NR4 is a shorter-lookback relative of NR7, which requires the narrowest range of the past seven days, a stricter, less frequent version of the same idea.
Narrow Range 4 (NR4): Reading a Volatility-Compression Bar
A Narrow Range 4 (NR4) bar is a daily bar whose high-low range is the narrowest of the past four trading days. Because a shrinking range often means fewer active participants and less realized volatility, traders watch NR4 bars as a volatility-compression signal, a setup that frequently precedes a breakout once trading activity picks back up, even though the pattern itself gives no clue which direction that breakout will take.
What Is an NR4 Bar?
An NR4 bar is defined purely by comparison: take the high-low range of each of the last four daily bars, and if the most recent one is smaller than the other three, it qualifies as NR4. Unlike a candlestick shape such as a doji or a hammer, NR4 has no requirement about where the open and close sit within the bar, only that the bar's total range is unusually small relative to its own recent history.
That relative framing is the key idea. A range that would look ordinary during a quiet, low-volatility stretch of the market can qualify as NR4 during a more active stretch simply because it's the tightest of the last four sessions. The signal is about contraction relative to recent context, not an absolute size threshold.
How an NR4 Setup Forms
An NR4 setup typically builds over several sessions: ranges that start out wider gradually contract as buying and selling pressure come closer to balance, culminating in a bar whose range is the tightest of the four-day window. That contraction reflects indecision or a temporary pause, participants aren't aggressively pushing price in either direction, and the resulting bar compresses.
Because volatility tends to cluster and then release, a period of unusually tight ranges is often followed by an expansion once new information, order flow, or a broader market move breaks the standoff. That's why NR4 is grouped with other range-contraction signals as a pre-breakout condition rather than a pattern with a fixed directional bias of its own.
NR4 Bar Example
The chart below shows a deterministic, illustrative example: four consecutive daily bars with progressively tighter ranges, ending in a bar whose range is visibly the smallest of the four, the NR4 bar. Toggle between two possible continuations: a confirmation (price expands into a breakout beyond the NR4 range) and a failure/look-alike (price pushes out briefly but closes back inside the NR4 bar's range, undoing the breakout read).
How to Trade an NR4 Setup
Treat the range itself as the level
The NR4 bar's own high and low become the two levels to watch: a close beyond either one is the event traders are waiting for, not the narrow bar itself. Until that close occurs, the compression is only a condition, not a signal to act on.
Confirm the breakout before acting
Because a brief push beyond the NR4 range can reverse just as quickly as it appeared, most approaches wait for a confirmed close beyond the NR4 bar's high or low, ideally with supporting volume, before treating the compression as resolved in a given direction.
Read it alongside broader context
An NR4 bar that forms within a clear trend, near a well-established support or resistance level, or alongside other range-contraction signals is generally read as more meaningful than an isolated NR4 bar in the middle of a choppy, directionless stretch.
Common NR4 Mistakes
- Assuming NR4 predicts direction, NR4 only flags that a range has compressed; it says nothing about which way the eventual breakout will go.
- Acting before a confirmed close, a brief intraday push beyond the NR4 bar's high or low is not the same as a close that holds beyond it.
- Ignoring the broader trend and nearby levels, an NR4 bar in isolation carries less weight than one that lines up with trend direction or a real support/resistance zone.
- Confusing NR4 with NR7 or other lookback windows, see the comparison below; a narrower or wider lookback changes how strict and how frequent the signal is.
NR4 vs. Similar Range-Contraction Signals
| Term | What it emphasizes | Key difference from NR4 |
|---|---|---|
| Narrow Range 4 (NR4) | Narrowest daily range of the past 4 sessions | Baseline, a rolling, relative comparison over a 4-day lookback |
| Narrow Range 7 (NR7) | Narrowest daily range of the past 7 sessions | Same idea over a longer lookback, a stricter, less frequent condition than NR4 |
| Inside bar | A bar whose entire high-low range sits within the prior bar's range | Defined by containment within one specific prior bar, not by comparing ranges across four days |
| Doji | A single bar with an open and close very close together | Defined by where price closed within the bar, not by the bar's overall range versus recent days |
Limitations of NR4 Analysis
NR4 is a purely relative, mechanical comparison, it identifies that a range has compressed, but it carries no information about why, and no guarantee that a breakout follows at all. A market can sit in NR4 territory repeatedly during a genuinely quiet stretch without ever producing a meaningful expansion. Like any single pattern, NR4 is best combined with trend context, nearby support and resistance, and a defined confirmation plan rather than traded in isolation.
Quiet Markets Produce These in Clusters
NR4 is a rolling relative comparison, which means it says a bar was the narrowest of four rather than that it was narrow in any absolute sense. During a genuinely quiet stretch, where every session is subdued, the test keeps getting satisfied and the chart produces NR4 bars repeatedly without any of them preceding an expansion. The signal frequency rises exactly when the underlying condition is least informative.
That is worth knowing before building anything on it. A run of NR4 bars is not accumulating evidence; it is the same mechanical comparison passing repeatedly in a market that is simply calm.
The pattern is also deliberately directionless. It flags that a range compressed and offers nothing about which way the eventual expansion goes, so a break of the bar high or low is where any directional read starts, and a brief intraday push beyond it is not the same as a close that holds.
An NR4 in isolation is thin evidence. One that coincides with trend direction or sits at a level that has mattered before is a more considered setup, and even then the compression can persist without ever producing a meaningful move.
NR4 FAQs
What is a Narrow Range 4 (NR4) bar?
A Narrow Range 4 (NR4) bar is a daily bar whose high-low range is the narrowest of the past four trading days. Traders watch it as a volatility-compression signal, often ahead of a potential breakout, because it marks a session where price traded in an unusually tight band relative to its own recent history.
How do you identify an NR4 bar on a chart?
Compare each day's high-low range to the ranges of the three days before it. If the current day's range is smaller than all three prior ranges, it qualifies as an NR4 bar. Most charting platforms can compute and flag this automatically, but it can also be read visually as the shortest of four consecutive bars.
Does an NR4 bar predict which direction price will break out?
No. An NR4 bar flags that volatility has compressed, not which direction the eventual move will take. Traders typically wait for price to close beyond the NR4 bar's high or low, or use other context like trend direction and volume, before forming a directional view.
What is the difference between an NR4 and an NR7 bar?
Both describe the same kind of range-contraction signal at different lookback lengths. An NR4 bar has the narrowest range of the past four days; an NR7 bar has the narrowest range of the past seven days. NR7 is a stricter, less frequent condition than NR4 because it compares against a longer window.
What invalidates an NR4 breakout setup?
If price closes back inside the NR4 bar's own high-low range after appearing to break out, the breakout reading is invalidated and the compression may simply continue or resolve later. A close that fails to hold beyond the NR4 bar's range is generally treated as a false start rather than a confirmed move.
Is the NR4 range measured in absolute terms or relative to volatility?
In absolute terms: the bar simply has to have the smallest high-to-low range of the last four. There is no normalisation, so the pattern appears more often in quiet stretches and less often when the instrument is generally active. That is usually the intent, since the point is to identify contraction, and it does mean NR4 counts are not comparable between periods of very different volatility.
Can an NR4 bar also be an inside bar?
Yes, and the combination is a stricter condition than either alone. An inside bar is contained within the previous bar; an NR4 is the narrowest of four. A bar satisfying both is narrow relative to a short history and contained by its immediate predecessor. Some frameworks screen for the combination specifically, which produces far fewer instances than NR4 on its own.
Does NR4 behave differently in low-priced instruments?
It can become trivial. Where the tick size is a large fraction of the price, bar ranges are quantised into a small number of possible values and many bars have the same range, so ties are frequent and the narrowest of four is often not meaningfully narrower than the others. The pattern still triggers and it stops describing a contraction.
How is NR4 combined with a breakout trigger?
The usual arrangement pairs the contraction with an expansion condition: the NR4 identifies the setup and a break of that bar high or low supplies the trigger. That gives the framework two parameters, one for the contraction window and one for how far beyond the bar counts as a break. Both need stating, since the pattern alone gives no entry.