Gap Trading

When the forex market re-opens after the weekend, price sometimes leaps to a new level, leaving an empty gap on the chart between Friday's close and the new open. Those gaps tend to behave in recognisable ways — often filling, sometimes running — and exploiting that behaviour is a niche but well-defined strategy. This guide explains gap trading: what gaps are in forex, the all-important gap-fill tendency, the two main approaches (fade versus continuation), and the risks.

It builds on price gaps (the what) and the related gap risk, and overlaps with news trading when a gap is news-driven.

Key takeaways

Gaps in forex

First, a forex-specific point: where do gaps even come from in a market that trades nearly 24 hours? Because spot forex runs continuously from the Sunday/Monday open through to the Friday close, intraday gaps are rare — price usually moves smoothly tick to tick. The main gaps in forex occur at the weekly re-open: the market is closed over the weekend, so if news or developments occur while it's shut, price can open on Sunday/Monday at a level away from Friday's close, leaving a weekend gap (see price gaps and gap risk). Smaller gaps can also appear around major scheduled news or in thin conditions. So in forex, "gap trading" is largely weekend-gap trading — a more limited, periodic opportunity than in stocks (which gap at every daily open), which is why it's a niche rather than a core strategy.

Fade vs continuation

The central observation gap traders exploit is the gap-fill tendency: a gap "fills" when price returns to the level it gapped from, closing the empty space on the chart, and many gaps — especially smaller weekend gaps without strong news behind them — tend to fill relatively soon, as price drifts back toward the prior close. This gives rise to two opposing approaches.

Fading the gap is the most common gap strategy: betting the gap fills, so you trade in the direction that would close it — selling an up-gap (expecting price to fall back to the prior close) or buying a down-gap (expecting a rise back). The target is the prior close (the gap-fill level), the stop sits beyond the gap (if it keeps running, you're wrong), and the edge is the statistical tendency of small, news-less gaps to revert. Trading the gap (gap-and-go / continuation) is the opposite: betting the gap runs, so you trade with its direction — this suits larger gaps driven by significant news or a genuine shift in sentiment, where the gap reflects a real repricing that's likely to continue rather than reverse. The skill is judging which regime you're in: small, unexplained gaps lean toward filling (fade), while large, news-driven gaps lean toward running (continuation) — though neither is guaranteed.

And that uncertainty is exactly the risk. The cardinal danger is that not all gaps fill: a gap driven by important news or a true sentiment shift can run instead of reverting, so a fade trade gets caught in a continuing move against you — which is why a stop beyond the gap is essential, and why judging the driver (is there a big news reason?) matters so much before fading. Other practical risks in forex: weekend gaps are infrequent and often small, limiting opportunities; the weekend re-open can be illiquid, with wider spreads and possible slippage right when you're trying to trade the gap; and a gap can be a sign of exactly the kind of gap risk that hurts positions held over the weekend. So the honest framing, as always: the gap-fill tendency is a real, exploitable edge — but a statistical tendency, never a guarantee. Gap trading works for those who respect that distinction: trade the right gap type with the right approach, judge the news driver, always use a stop (gaps that run can run far), size sensibly, and treat it as a periodic, niche opportunity rather than a reliable bread-and-butter strategy. The honest framing: gap trading profits from price gaps — in forex, mainly weekend gaps at the weekly re-open (and around major news), since spot FX trades continuously midweek. The key tendency is gap-fill: many small, news-less gaps revert to the prior close. Two approaches: fade the gap (bet it fills — trade toward the prior close; best for small, unexplained gaps) or trade the gap/continuation (bet it runs — trade with it; best for large, news-driven gaps). The main risk is that not all gaps fill — news-driven gaps can run — so judge the driver, always use a stop beyond the gap, mind thin re-open liquidity, and treat the fill tendency as an edge, not a guarantee.

Practical rules and judgement

Trading gaps well comes down to a short checklist applied with judgement. Measure the gap: note its size relative to the pair's normal range — a small weekend gap (a modest fraction of the average daily range) leans toward filling and suits a fade, while a large gap suggests something significant happened and is more likely to run. Check the driver: this is the crucial judgement — why did the gap occur? A gap with no clear news behind it (just thin weekend conditions) is a classic fade candidate, whereas a gap driven by a major weekend development (a geopolitical event, an election, a central-bank surprise) reflects a real repricing that may well continue, favouring continuation or standing aside — so always glance at what happened over the weekend before fading. Wait for confirmation rather than acting on the very first tick of the re-open: let price show its hand (e.g. begin to drift back toward the prior close for a fade, or push on for a continuation) before committing, since the chaotic first moments of the re-open are unreliable.

Then define the trade precisely: for a fade, the target is the gap-fill level (the prior close) and the stop sits beyond the gap (if it keeps running, the fade thesis is wrong — exit); for a continuation, trade with the gap with a stop on the other side. Mind the re-open conditions: the weekend re-open is often illiquid with wider spreads and possible slippage, so the practical cost of trading right at the open can be higher — some traders wait for liquidity to normalise before acting. Consider a time-based exit too: if a fade hasn't filled within a reasonable window, the tendency may not be playing out, and exiting beats hoping. And keep the opportunity in proportion: forex gaps are infrequent (mainly weekends) and often small, so gap trading is a periodic, niche add-on, not a core strategy — don't force trades on tiny or absent gaps just to be active. Above all, hold the gap-fill tendency as exactly that — a tendency, not a rule: it gives a real statistical edge on the right gaps, but plenty of gaps don't fill, so the stop and sizing are what make the strategy survivable when a gap you faded decides to run. The honest reminder: measure the gap size, check the news driver (no-news small gaps fade; big news-driven gaps may run), wait for confirmation, define target (prior close for a fade) and stop (beyond the gap), mind thin/wide-spread re-open liquidity, consider a time-based exit, and treat it as a periodic niche edge — the fill is a tendency, never a rule.