A gap is one of the most visually obvious things on a price chart: a blank space where the price jumped from one level to another with no trading in between. Most of the time that jump happens between one session’s close and the next session’s open, when news, earnings, or data hit while the market was shut and the price reopens somewhere else. Some gaps are pure noise. Others mark the start of a major trend or the moment one runs out of steam. The skill is telling them apart.
The short version: gaps come in two directions, up (bullish) and down (bearish), and four classic types, common, breakaway, runaway, and exhaustion. The type depends on where the gap appears in a trend and how much volume comes with it, and that combination is what tells you whether to ignore the gap or pay close attention. This guide is about reading gaps on the chart; for why a gap can wreck your stop-loss fill, that’s a separate execution question covered in our drawdown and loss-limit material.
What a Market Gap Is
A gap is a price range on the chart where no trading took place. For an up gap, the lowest price after the open is higher than the previous session’s high. For a down gap, the highest price after the open is lower than the previous session’s low. Either way, the market has effectively skipped a band of prices.
Gaps form because extraordinary buying or selling builds up while the market is closed. An unexpectedly strong earnings report after the close generates overnight demand, supply and demand fall out of balance, and the stock opens higher the next morning. The gap is the visible footprint of that imbalance, and it’s evidence that something shifted in either the fundamentals or the crowd’s psychology.
Up Gaps vs Down Gaps
The direction is the first read. An up gap, where price opens above the prior session’s high, reflects a surge of buying interest and is generally bullish. A down gap, where price opens below the prior session’s low, reflects a rush of selling and is generally bearish. Direction alone doesn’t tell you whether the move will last, though. For that, you need the type.
The Four Types of Gaps
Gaps divide into four categories based on where they sit in a trend and the volume behind them.
Common gaps. Sometimes called trading or area gaps, these are the uneventful ones. They tend to appear inside a trading range on low volume, signal little about direction, and usually get filled quickly as price drifts back over the next few days or weeks. They rarely offer much of a trading opportunity and are mostly worth recognizing so you don’t mistake them for something bigger.
Breakaway gaps. These occur when price gaps out of a congestion area or trading range on heavy volume, marking the start of a new trend. The breakout level often flips into new support (for an upside break) or resistance (for a downside break), and the move tends to keep going. Importantly, breakaway gaps can take a long time to fill, if they fill at all, so treating one as a quick fade is a good way to get run over. They’re stronger still when they break a recognizable chart pattern.
Runaway gaps. Also called continuation or measuring gaps, these appear in the middle of an established trend, driven by a fresh wave of interest, often latecomers piling in who feared they’d missed the move. They come with strong volume and confirm the trend’s momentum. The “measuring” nickname comes from the rough idea that they tend to occur around the halfway point of the overall move. In futures, exchange-imposed daily price limits can also produce runaway-style gaps.
Exhaustion gaps. These show up near the end of a trend and are often the first hint it’s running out. They look a lot like runaway gaps, with a large price jump, but the tell is exceptionally high volume followed by a stall. After a final burst of euphoria or panic, the move reverses and the gap fills quickly. Mistaking an exhaustion gap for a runaway gap, by ignoring that climactic volume, is a classic and costly error.
Here’s the quick comparison:
| Gap type | Where in the trend | Volume | Usually fills? | What it signals |
|---|---|---|---|---|
| Common | Inside a range | Low | Yes, quickly | Noise, little meaning |
| Breakaway | Start of a trend | High | Often not soon | A new trend beginning |
| Runaway | Middle of a trend | High | Often not soon | Trend momentum continuing |
| Exhaustion | End of a trend | Very high | Yes, quickly | A reversal approaching |
Do All Gaps Get Filled?
A gap is “filled” when price later retraces to the level where the gap began, closing the blank space on the chart. You’ll hear the adage that all gaps eventually fill, and it’s only partly true. Common and exhaustion gaps tend to fill readily. Breakaway and runaway gaps can stay open for a long time, sometimes indefinitely, because they mark a genuine shift the market doesn’t want to reverse. Acting on the assumption that every gap fills is risky in both directions: fading a breakaway gap waiting for a fill can be punishing, and waiting for a gap to fill before joining a strong trend can leave you watching the move from the sidelines. Unfilled gaps also tend to act as future support and resistance levels, which is often more useful than betting on a fill.
Why Volume and Location Matter
Two clues separate a meaningful gap from noise: where it sits in the trend, and how much volume came with it. High volume signals real conviction and points toward a breakaway, runaway, or exhaustion gap, while low volume usually marks a forgettable common gap. Location then tells you which of the high-volume types you’re looking at, since the same large gap means very different things at the start, middle, and end of a move. Thinly traded instruments gap almost daily on little volume, which is mostly noise rather than signal, and brief intraday gaps that close by the session’s end are usually just normal volatility.
How Gaps Show Up Across Markets, and Why Prop Traders Should Care
Different markets gap in different ways. Stocks gap overnight on earnings and after-hours news. Forex gaps over the weekend, between Friday’s close and Monday’s open. Futures trade nearly around the clock, so they gap less often, but they still jump on weekend or off-hours news and can see limit-move gaps when an exchange’s daily price limits are hit. Our guide to futures versus CFDs covers more of those structural differences.
For a funded trader, gaps are a risk-management issue as much as an analysis one. If you hold a position through a session break and the market gaps against you, the price can open well past your stop, and because a stop becomes a market order, you fill at the new level rather than your intended one. That single gap can push your loss beyond your daily loss limit or your maximum drawdown and end the account, which is a large part of why many firms restrict holding over the weekend. Reading gaps helps you both find opportunities and avoid being on the wrong side of one while you can’t act.
Bottom Line
A market gap is the chart’s record of the price repricing while you couldn’t trade, and its meaning lives in two details: the direction, up or down, and the type, common, breakaway, runaway, or exhaustion, judged by volume and where it falls in the trend. Common gaps are noise, breakaway and runaway gaps confirm a move worth respecting, and exhaustion gaps warn that one is ending. Don’t assume every gap fills, lean on volume and location to read intent, and in a funded account treat gap risk seriously, because a gap through your stop can breach your limits before you ever get a say.
Frequently Asked Questions
What is a market gap?
A gap is a blank space on a price chart where no trading occurred, usually between one session’s close and the next session’s open. It forms when buying or selling builds up while the market is closed and the price reopens at a different level.
What’s the difference between an up gap and a down gap?
An up gap opens above the previous session’s high and reflects strong buying interest, so it’s generally bullish. A down gap opens below the previous session’s low and reflects strong selling, so it’s generally bearish.
What are the four types of gaps?
Common gaps (noise inside a range), breakaway gaps (the start of a new trend on high volume), runaway gaps (mid-trend continuation on strong volume), and exhaustion gaps (a high-volume jump near the end of a trend that often precedes a reversal).
Do all gaps get filled?
Not always. Common and exhaustion gaps tend to fill quickly, but breakaway and runaway gaps can stay open for a long time. The popular idea that every gap fills isn’t reliable, and trading on it can be costly.
Why does volume matter for gaps?
Volume separates a meaningful gap from noise. High volume points to a breakaway, runaway, or exhaustion gap that reflects real conviction, while a low-volume gap is usually a forgettable common gap. Combined with location in the trend, volume tells you which type you’re seeing.
Do gaps matter for prop traders?
Yes. Beyond analysis, a gap can open past your stop while you hold a position through a session break, and since a stop fills as a market order, the loss can exceed your daily loss limit or drawdown and end the account. It’s a key reason many firms limit weekend holding.