A fair value gap is a three-candle imbalance where price moved so fast it left a one-sided zone behind. Bullish vs bearish FVGs, mitigation and inversion, the ICT context, and how to backtest FVG setups on NQ.

Fair Value Gap (FVG) Explained: How to Find and Trade FVGs

A fair value gap (FVG) is a three-candle pattern where the middle candle moves so fast that the first candle's wick and the third candle's wick never overlap — leaving a price zone that traded in only one direction. In a bullish FVG, there's a gap between candle 1's high and candle 3's low. In a bearish FVG, between candle 1's low and candle 3's high. The idea, popularized by ICT (Inner Circle Trader) concepts, is that these one-sided zones act as magnets and reaction points when price revisits them.

Here is the precise definition, how bullish and bearish FVGs differ, what mitigation and inversion mean, how FVGs fit into the broader ICT framework, what they look like on NQ, and — most importantly — how to test whether FVG setups actually carry an edge before you trade them.

The three-candle definition

Take any three consecutive candles:

Bullish FVG: candle 2 is a strong up candle, and candle 3's low stays above candle 1's high. The zone between candle 1's high and candle 3's low is the gap.
Bearish FVG: candle 2 is a strong down candle, and candle 3's high stays below candle 1's low. The zone between candle 1's low and candle 3's high is the gap.

The middle candle is the engine: it moved with enough force that price never auctioned back through the zone. Some traders call the same structure an "imbalance" or "inefficiency" — the market printed prices where, on that pass, essentially all the aggression came from one side.

A practical marking tip: draw the rectangle from candle 1's wick to candle 3's wick, not body to body, and extend it right. The midpoint of the gap — ICT calls it consequent encroachment (CE) — is commonly treated as the decision level inside the zone.

Why gaps form (the honest version)

The ICT narrative says institutions leave inefficiencies they later return to "rebalance." The mechanically verifiable part is simpler: a large market order sweep, a news print, or a stop cascade consumes all resting liquidity in one direction, price jumps, and the skipped zone has genuinely thin traded history. Price often does retrace into these zones — but "often" is a statistic to measure, not an article of faith. Both explanations give you the same testable pattern; neither guarantees a reaction.

Mitigation, fills, and inversion

Mitigation: price trades back into the gap and reacts — the common bullish play is a retrace into the FVG that holds at or before CE, then continuation.
Full fill: price trades through the entire zone. The gap is spent; most traders delete it.
Inversion (iFVG): price doesn't just fill the gap — it closes through it decisively. A failed bullish FVG then gets treated as resistance; a failed bearish FVG as support. Same rectangle, flipped role. Inversions matter because they tell you the side that created the gap has lost control.

Age matters too: an FVG from ten minutes ago on a 1-minute chart and one from last week on the hourly are different animals. Most intraday traders only track gaps from the current and prior session.

FVGs in the ICT context

In ICT-style trading, an FVG is rarely the whole trade. The typical sequence is:

Liquidity sweep — price runs stops above an obvious high or below an obvious low.
Displacement — an aggressive reversal leg that creates the FVG.
Retrace into the FVG — entry in the gap (often at CE), stop beyond the sweep, target the opposite liquidity pool.

The FVG marks where to engage; the sweep and displacement are the evidence that someone with size just changed direction. Reading that sequence requires reading market structure — swings, breaks of structure, and where stops cluster.

What FVGs look like on NQ

NQ is a fast, thin-ish contract that displaces constantly, which cuts both ways:

Around the 9:30 ET open and scheduled news, NQ prints large, clean FVGs — the kind the setup was designed for.
On a 1-minute chart during quiet hours, three-candle gaps appear dozens of times a session. Most mean nothing. Ubiquity is the number-one practical problem with FVGs on low timeframes.

Filters traders apply on NQ: minimum gap size (e.g., only gaps of several points, not ticks), time-of-day windows (first 90 minutes), alignment with a higher-timeframe FVG or level, and only gaps created by a move that also broke structure. Which filters actually help is exactly what testing is for.

How to backtest an FVG setup

FVG trading fails backtests most often because the rules were never pinned down. Fix every degree of freedom first:

Timeframe: e.g., 5-minute NQ only.
Qualifying gap: minimum size in points; created by a candle that swept a prior swing; formed between 9:30 and 11:00 ET.
Entry: limit at CE (the 50% of the gap), or on touch of the near edge — pick one.
Stop: one tick beyond the far edge of the gap, or beyond the displacement swing — pick one.
Target: fixed 2R, or the opposite session liquidity — pick one.
Invalidation: skip the trade if price closes through the gap before your entry fills.

Then replay 30–50 historical sessions bar by bar and take every qualifying setup. Log fills, win rate, average R, and how often the gap inverts instead of holding. Hindsight is the enemy here — on a static chart, every winning FVG is obvious and every losing one is forgettable. Bar-by-bar replay forces you to mark the gap before you know the outcome, which is the only honest way to test a discretionary pattern. Sample-size rules of thumb are covered in how to backtest a trading strategy.

FAQ

What's the difference between an FVG and a regular gap?

A classic gap is empty space between one candle's close and the next candle's open (common across sessions). An FVG occurs within continuous trading — price printed through the zone, but only in one direction, wick-to-wick across three candles.

Do fair value gaps always get filled?

No. Many get partially filled to CE and reverse; many fill completely; some never get revisited, especially in strong trends. "FVGs always fill" is not a statistic anyone has credibly verified — treat fill probability as something you measure on your own market and timeframe.

What timeframe is best for FVGs?

Higher timeframes produce fewer, more meaningful gaps; 1-minute charts produce constant noise. A common intraday compromise on index futures is marking gaps on the 5- or 15-minute and executing on a lower timeframe.

Is an FVG bullish or bearish?

The gap itself has the direction of the candle that made it — but its message depends on what price does at it. A bullish FVG that holds is continuation evidence; one that inverts is reversal evidence.

Practice spotting FVGs bar by bar

The skill isn't defining an FVG — it's marking the right ones in real time and sitting on your hands for the rest. TestMax replays real historical NQ, ES, and EURUSD data candle by candle, so you can rehearse the full sequence — sweep, displacement, gap, retrace — across dozens of sessions without risking a dollar. Start free and run your FVG rules through a real backtest. Simulated results don't guarantee live results.