Direct Answer
A price gap occurs when a bar opens beyond the prior bar's high or low, leaving a price range on the chart where no trading occurred. What separates a runaway gap from any other gap is its location and its behavior: it appears after a trend is already clearly underway, not at the start of a new move and not near its exhaustion, and price does not trade back through it soon after it forms.
Key Takeaways
- A runaway gap forms in the middle of an established trend, roughly midway through the move, rather than at the trend's start or end.
- It is not quickly filled, price continues away from the gap instead of trading back through it soon after it forms.
- Because it tends to sit near the halfway point of a trend, traders sometimes use it to roughly estimate how much further the move may extend, the "measuring gap" technique.
- A runaway gap is one of three commonly described gap types by location in a trend: breakaway (start), runaway (middle), and exhaustion (end).
- If the gap fills soon after forming, the runaway-gap reading is invalidated, the move may be exhausting rather than continuing.
Runaway Gaps (Measuring Gaps)
A runaway gap, also called a measuring gap, is a gap that occurs in the middle of an established trend, roughly midway through the move, and is not quickly filled. Because it tends to appear near the trend's halfway point, traders often use the distance the trend has already covered to roughly estimate how much further the move may still run.
What Is a Runaway Gap?
A price gap occurs when a bar opens beyond the prior bar's high or low, leaving a price range on the chart where no trading occurred. What separates a runaway gap from any other gap is its location and its behavior: it appears after a trend is already clearly underway, not at the start of a new move and not near its exhaustion, and price does not trade back through it soon after it forms. The trend simply continues on the other side of the gap.
The name "runaway" reflects the idea that the trend is running away from the crowd that hesitated, participants who were waiting for a pullback to enter get a gap instead, and the move continues without giving them one. The related name "measuring gap" reflects the traditional use of the gap's position to roughly estimate the move's remaining extent.
How a Runaway Gap Forms
A runaway gap requires an established trend already in place, a series of higher highs and higher lows in an uptrend, or the reverse in a downtrend, with enough prior bars to make clear the move is not brand new. Partway through that continuation, a bar opens beyond the prior bar's extreme, leaving a gap between the two. For the gap to qualify as a runaway gap rather than an ordinary pause, price needs to hold on the far side of the gap: subsequent bars should not trade back into the gap and fill it soon after it forms.
The gap's rough position in the trend, appearing after a meaningful move is already established, rather than at the very start, is what distinguishes it from a breakaway gap. Whether it sits closer to the trend's midpoint or further along is only visible in hindsight, once the trend's eventual full length is known.
Runaway Gap Example
The chart below shows a deterministic, illustrative example: an established uptrend, then a gap partway through the continuation that holds without filling. Toggle between two possible continuations: a confirmation (the trend keeps extending and the gap is never touched) and a failure/look-alike (price reverses and trades back down through the gap, filling it).
How to Trade a Runaway Gap
Confirm the trend is already established
A gap that appears at the very start of a move, right out of a consolidation range, is more likely a breakaway gap than a runaway gap. Before treating a gap as a runaway gap, check that a clear trend with several prior swings was already in place before the gap formed.
Wait to see whether the gap holds
The defining behavior of a runaway gap is that it is not quickly filled. Rather than assuming a gap qualifies the moment it appears, most approaches wait for several subsequent bars to confirm price is not trading back into the gap before treating it as a genuine runaway gap.
Use the measuring-gap estimate cautiously
The traditional measuring-gap technique treats the distance from where the trend began to the gap as a rough guide to how much further the trend may extend beyond the gap. This is an approximation based on the gap's typical position in a trend, not a formula that produces a reliable price target, treat it as one input alongside other trend, level, and momentum evidence, not a stand-alone signal.
Common Runaway Gap Mistakes
- Calling any mid-trend gap a runaway gap immediately, the gap needs to actually hold without filling; a gap that closes back through within a bar or two was not a runaway gap.
- Confusing a runaway gap with a breakaway gap, a gap right at the start of a new trend, out of a range, is a different pattern with a different implication.
- Treating the measuring-gap estimate as a precise target. It is a rough historical tendency, not a formula guaranteed to project the exact remaining move.
- Ignoring what happens if the gap fills, a filled gap invalidates the runaway-gap reading and can instead suggest the trend is losing momentum.
Runaway Gap vs. Other Gap Types
| Gap type | Typical location in trend | Key difference from a runaway gap |
|---|---|---|
| Runaway gap (measuring gap) | Middle of an established trend | Baseline, forms after a trend is already underway and holds without filling |
| Breakaway gap | Start of a new trend, leaving a consolidation range | Marks the beginning of the move rather than the middle of one already in progress |
| Exhaustion gap | Late in a trend, near its eventual end | Signals the move may be running out of participants rather than continuing, and is more prone to filling quickly |
| Common gap | Anywhere, often within a trading range | Not tied to a trend's start, middle, or end, and typically fills relatively quickly with little significance |
Limitations of Runaway Gap Analysis
Whether a gap turns out to be a runaway gap can only be confirmed in hindsight, once it is clear the trend was already established beforehand and that price did not trade back through the gap afterward. In real time, a mid-trend gap can look identical to a gap that is about to fill or to an early exhaustion gap; there is no way to distinguish them with certainty at the moment the gap forms. The measuring-gap distance estimate is a rough historical tendency, not a reliable price target, and should be combined with trend, level, and volume context rather than used on its own.
The Measuring Estimate Is Not a Target
The measuring technique is the most attractive part of this pattern and the part that deserves the most caution. Doubling the distance already travelled produces a specific number, and specific numbers are persuasive out of proportion to their basis. What sits behind it is a rough historical tendency for such gaps to appear near the middle of a move, not a rule the market follows, and trends routinely end well short of the estimate or run far past it.
Using it as a place to start thinking about where a move might slow is reasonable. Using it as a profit target, sized and committed to, treats a heuristic as a measurement.
The classification is also retrospective. A mid-trend gap that has just formed looks identical to one about to fill and to an early exhaustion gap, and only the following bars separate them. Whether the trend was genuinely established beforehand is the other half of the definition, and it is a judgment about the preceding chart.
One requirement is easy to state and easy to skip: the gap has to hold. A mid-trend gap that closes back through within a bar or two was never a runaway gap, and applying the measuring technique to it is applying a rough tendency to a pattern that did not occur.
Runaway Gap FAQs
What is a runaway gap?
A runaway gap is a gap that occurs in the middle of an established trend, roughly midway through the move, and is not quickly filled. Because it tends to appear near the halfway point of a continuing trend. It is often used to estimate how much further the move may still have to run.
How is a runaway gap different from a breakaway gap or an exhaustion gap?
A breakaway gap forms at the start of a new trend, as price leaves a consolidation range. A runaway gap forms in the middle of a trend that is already established. An exhaustion gap forms near the end of a trend, often just before the move stalls or reverses. The three describe the same basic event, a price gap that holds, happening at three different points in a trend's life cycle.
How do traders use a runaway gap to estimate a move's remaining extent?
Because a runaway gap tends to sit roughly midway through a trend, some traders use the distance already covered, from where the trend began to the gap, as a rough estimate of how much further the trend may extend beyond the gap. This is commonly called the measuring gap technique. It is an approximation drawn from the gap's typical position in a trend, not a fixed rule, and it can be wrong on any individual move.
What invalidates a runaway gap?
If price later trades back through the gap and fully fills it, closing beyond the gap's far edge, back toward the level the trend was at before the gap formed, the runaway-gap reading is invalidated. A gap that fills quickly did not hold, so it does not function as a mid-trend runaway gap and should not be used to estimate the trend's remaining extent.
Does a runaway gap need to appear on high volume?
A runaway gap is defined by its position in the trend and by holding without filling, not by a specific volume threshold. Volume evidence supporting continued participation can add confidence that the gap reflects real, sustained interest rather than a thin, easily-reversed print, but the pattern itself is a price-and-location definition.
Can a single move contain more than one runaway gap?
Yes, and it complicates the measuring convention immediately. If the halfway reasoning is applied to a gap and a second one appears later, the two projections disagree. Practitioners handle this by taking the first, or by taking the largest, or by abandoning the projection. None of those is derived from anything, which is a reason to treat the projection as a convention rather than a method.
How is a runaway gap distinguished from a breakaway gap at the time?
By what preceded it, which is the only information available. A gap emerging from a defined base is classified as breakaway; one occurring after a move is already underway is classified as runaway. That means the classification is decidable at the time, unlike the exhaustion category, which needs the move to have ended. The distinction rests entirely on the reading of the prior structure.
Do runaway gaps get filled?
The traditional description says they tend not to fill while the move continues, which is close to circular: a gap that fills has usually been followed by a reversal, at which point the move was not continuing. Stated as a testable claim it needs a horizon and a definition of fill, and framed that way it is a question about the specific instrument rather than a general property.
Does a runaway gap create a level below it?
The lower edge of the gap becomes a reference, since it is the last price traded before the discontinuity. It is watched as a point at which the continuation would be called into question. That is a reasonable use of the gap edge and it should not be confused with a level formed by repeated trading, since by definition nothing traded inside the gap at all.