Chart gaps: common, breakaway, runaway, exhaustion and island gaps

A chart gap is an empty space on a price chart: a range of prices at which no trade took place between one bar and the next. On a daily chart, a gap up means today's low is above yesterday's high; a gap down means today's high is below yesterday's low. Gaps happen when news, earnings or a shift in sentiment arrives while the market is closed and the next session opens far from where the last one ended.

Chart readers have classified gaps for more than seventy years, because where a gap appears in a trend says a lot about what it means. A gap inside a quiet range is usually noise. The same size gap out of that range may start a new trend, and a gap late in a long run may end one. This guide covers the five classic types, how to tell them apart, what happens to true gaps afterwards by size, and real examples from AMD, Meta and Alphabet in 2025.

True gaps and opening gaps

Two different things are both called "gaps," and it helps to keep them apart.

Every true gap starts with an opening gap, but most opening gaps are not true gaps: the price trades back into the prior day's range during the session, and the empty space never appears on the chart. The Gap trading: price gap types, gap fills and what the data shows guide measures opening gaps and how often they fill the same day. This page is about the gaps that remain visible on the chart.

A gap is filled (or closed) when price later trades back across the empty space: down to the prior bar's high after a gap up, up to the prior bar's low after a gap down. Gap edges often behave as Support and resistance: why price levels form and how to use them, because they mark the last prices traded before the market changed its mind.

The five gap types

Common gap

A common gap occurs inside a trading range or a quiet market, without an important level being crossed. It usually comes on ordinary volume and with no major news, and it tends to fill within days, because nothing about the market's balance has changed. Common gaps are most frequent in thinly traded stocks and in instruments that trade only part of the day.

Breakaway gap

A breakaway gap carries price out of a range, through support or resistance, or out of a chart pattern, usually on heavy volume and often on news. It is a breakout that happens overnight (see Breakouts and false breakouts: what the data says about each). Because it leaves behind a crowd of sellers who never got the chance to sell at the old prices, or buyers who never got to buy, a genuine breakaway gap often stays open for a long time. The gap's edges become support (for a gap up) or resistance (for a gap down).

Runaway gap

A runaway gap, also called a measuring or continuation gap, appears in the middle of an established trend, as the move accelerates. It shows that demand (in an uptrend) is strong enough that buyers will not wait for a pullback. Edwards and Magee observed that such gaps often occur near the midpoint of a move, which gave rise to the measuring rule: the distance from the start of the trend to the gap is projected beyond the gap. Treat the projection as a rough guide; many trends travel well past it.

Exhaustion gap

An exhaustion gap comes late in a long, fast move, often with a burst of volume, and marks the last surge of buyers (or sellers) rather than the start of something new. The giveaway is what happens next: an exhaustion gap typically fills within days, and the trend stalls or reverses. Before it fills, an exhaustion gap looks exactly like a runaway gap, which is why the label is usually applied in hindsight.

Island reversal

When an exhaustion gap is followed by a gap in the opposite direction, the bars between them are left isolated on the chart, an island. An island top (gap up, then gap down) or island bottom (gap down, then gap up) is a reversal pattern: everyone who traded on the island is trapped on the wrong side of the second gap. The island can be a single bar, which in candlestick terms resembles an Abandoned baby candlestick: the rare double-gap reversal, or a cluster of days or weeks.

What happens to true gaps: our data

We counted every true gap in two years of daily bars for 15 large US stocks and ETFs (SPY, QQQ, DIA, IWM, IYT, AAPL, MSFT, NVDA, TSLA, AMZN, META, GOOGL, AMD, JPM and XOM). There were 913, about one session in eight. For the 795 with at least 60 sessions of follow-up, we checked when each gap filled, counting from the next session.

The pattern fits the classic types. Small gaps, most of them common gaps, mostly filled fast. Large gaps, which in large stocks almost always come with news such as earnings, were much more likely to stay open, the behavior expected of breakaway and runaway gaps. Even so, two in five large gaps filled within a month, which is why a large gap is not automatically a breakaway gap. The sample covers large, liquid names in a mostly rising market; small caps and other periods will differ.

Real examples

A breakaway gap: AMD, October 6, 2025

From early September 2025, AMD traded in a range of roughly $150 to $171. On October 6, the day AMD and OpenAI announced a large chip supply agreement, the stock opened at $226.45 against a prior high of $170.68. The day's low was $203.01, leaving a gap of about 19%, and volume was 4.6 times its 50-day average. It closed at $203.71, up 24% on the day.

That is a breakaway gap by every test: it left a well-defined range, on news and heavy volume. The gap's upper edge then acted as support. In the November pullback AMD fell as low as $194.28 on November 25, back inside the gap but well above its lower edge, and recovered. As of October 29, 2026 the gap had never filled, and the stock had traded above $650.

A runaway gap: Alphabet, September 3, 2025

Alphabet had been rising since June 2025, from a low of $162.00 on June 23. On September 3, after a court ruling on remedies in the US government's search antitrust case, it opened well above the prior day's high of $211.68 and never traded below $224.79, a gap of about 6%, mid-trend. That gap had not filled by October 2026.

The measuring rule would project the June-to-September advance, about $50, beyond the gap, to around $275. Alphabet passed that level when it gapped higher again on October 30, 2025, and kept going to $328.83 by late November. The rule pointed in the right direction and badly underestimated the move, which is typical of such projections.

An island top: Meta, October 2025

Meta gapped up on October 27, 2025: its low that day, $748.01, was above the October 24 high of $741.21. It traded in a tight band near $750 for three sessions. Then, on October 30, after its quarterly results the evening before, it opened at $669.15. The day's high, $680.96, was far below the October 29 low of $742.51, a gap down of 8.3%, on 7.7 times average volume. The stock closed at $666.47, down 11.3%.

The three days from October 27 to 29 were left as an island, with buyers who paid around $750 trapped above an 8% hole. Meta kept falling to a low of $581.25 on November 19, about 23% under the island's high of $759.16. The gap down did not fill until January 29, 2026, 61 sessions later. Islands are rare and usually obvious only after the second gap; this one formed and was completed in four sessions.

An island bottom: Amazon, August 2025

The same shape appeared upside down in Amazon. On August 1, 2025, after its earnings, Amazon gapped down: the day's high of $220.44 was below the July 31 low of $231.40. It traded below that gap for nine sessions, then gapped up on August 14, when its low ($227.02) cleared the August 13 high ($224.92). The nine sessions were left as an island bottom, and the stock rose to $238.85 by September 9.

How to use gaps when reading a chart

1. Classify by context, not size alone. Ask where the gap sits: inside a range, out of a range, mid-trend or late in a long move.
2. Check the volume. Breakaway and exhaustion gaps usually come on heavy volume; common gaps don't.
3. Watch the next few sessions. A breakaway or runaway gap should hold; a quick fill turns a "breakaway" into a failed breakout and a "runaway" into an exhaustion gap.
4. Mark both edges as levels. The prior bar's extreme and the gap bar's extreme both tend to act as support or resistance.
5. Remember the risk. Gaps are also where risk concentrates: a stop order does not protect against an overnight gap, and fills at the next available price. The Stop-loss placement: volatility, structure and time stops and Trading earnings season: implied moves, IV crush and earnings gaps guides cover this.

Pitfalls

• Hindsight labels. Runaway and exhaustion gaps look identical on the day. Only the follow-through decides.
• "All gaps fill." Many do, eventually, but large gaps in our sample stayed open after 60 sessions 43% of the time, and AMD's October 2025 gap was still open a year later.
• Adjusted data. Dividends and splits adjust historical prices on most charts, which can create or remove small gaps. Very large one-day "gaps" can also be bad prints; check volume before trusting one.
• Different markets. Futures and crypto that trade around the clock show few daily gaps, and thinly traded stocks show many meaningless ones.

How Finabase helps

Gaps are easiest to see on candlestick charts, and every symbol's chart in Finabase draws daily and intraday candles, with a volume pane to check the volume behind each gap. Use the rectangle drawing tool to mark a gap's empty space from the prior bar's extreme to the gap bar's extreme and extend it to the right; you will see at once if a later pullback fills it. Signed-in users' drawings are saved per symbol.

The Scanner has Gap Up and Gap Down signals at 5% and 10%. Note that these are measured close to close, a day's change of at least 5% or 10%, rather than as true chart gaps, so they catch large moves whether or not empty space is left on the chart. Because most large gaps come on earnings, the earnings calendar is the best guide to which stocks are likely to gap next. Some candlestick patterns are built on gaps too, such as the Tasuki gap (upside and downside): a gap that holds on a pullback, Upside and downside gap three methods: when a gap gets filled and Kicking candlestick pattern: two marubozu and a gap.

Frequently asked questions

What is the difference between a breakaway gap and an exhaustion gap?

Location and follow-through. A breakaway gap leaves a range or crosses an important level at the start of a move, and it tends to stay open. An exhaustion gap comes late in a long, fast move and fills quickly as the trend stalls. On the day they happen they can look alike, so the next few sessions decide the label.

Do all gaps get filled?

No. Small gaps usually do: in our sample 82% of true gaps under 1% filled within 20 sessions. Large gaps often don't: 43% of gaps of 3% or more were still open after 60 sessions, and AMD's 19% gap from October 2025 was still open a year later.

What is an island reversal?

It is a group of bars separated from the rest of the chart by a gap on each side, for example a gap up followed a few days later by a gap down. It signals a reversal because everyone who bought on the island is trapped above the second gap. Meta formed a three-day island top in October 2025.

What is a measuring gap?

It is another name for a runaway gap, a gap in the middle of a strong trend. The name comes from the rule of thumb that such gaps often occur near the halfway point of a move, so the distance traveled before the gap is projected beyond it. The projection is rough and often falls short.

Are gaps support and resistance?

Often. The edges of a gap mark the last prices traded before the market jumped, and price frequently reacts there on a return. AMD's October 2025 gap edge held as support in November, and Meta's October 2025 gap down acted as a ceiling until January 2026.

Summary

Chart gaps are empty spaces where no trading took place, and their meaning depends on where they appear. Common gaps inside ranges are noise and fill fast; breakaway gaps start moves and tend to stay open; runaway gaps show an accelerating trend; exhaustion gaps mark its last burst; and an island, cut off by gaps on both sides, marks a reversal. Our data on 15 large US names fits that picture: small gaps mostly filled within weeks, large ones often stayed open. AMD's October 2025 breakaway, Alphabet's September runaway and Meta's October island top show each type on a real chart, and how much of the label depends on what happened next.