How to Trade a Gap
To trade a gap, first find out why it happened: a gap on company news behaves differently from one with no explanation. Then decide whether you are fading it or trading with it, because those are opposite positions, and size for the fact that stops cannot protect through a gap.
A gap is price opening away from the previous close, with no trading in between. It is the one chart event that is genuinely discontinuous, and that discontinuity is why the usual risk tools do not behave as expected.
Before you start
A decision about whether you are fading the gap or trading with it, made before the open. These are opposite trades and the chart at the open supports both.
The reason for the gap, because news and no news behave differently. An earnings release, an announcement, or nothing identifiable. One sentence.
A size that accounts for the fact that stops do not work through a gap. The next gap can open past your stop, and only the position size limits what that costs.
The steps
1. Find out why before anything else
A gap on a scheduled release, a gap on unscheduled news, or a gap with no explanation. Those are three different events and they behave differently.
2. Decide fade or follow before the open
Fading assumes the gap closes; following assumes it continues. Deciding after watching the first ten minutes means the first ten minutes decides, and they are noisy.
3. Wait for the opening range to form
The first fifteen or thirty minutes produce a high and a low. Those are levels you can trade against; the opening print is a single number with nothing around it.
4. Use the previous close as the reference
It is the level the gap is defined against, and it is where a fading trade targets. Everybody looking at the gap is looking at the same number.
5. Size for the next gap, not for this one
If you hold overnight, tomorrow’s open can be past your stop. On this site’s shared series the largest single bar measured 2.338 against a median of 0.493 — the tail is much wider than the typical case.
6. Take the stop from the opening range
Beyond the opposite side of the range established after the open. It is structural, it is visible to everybody, and it gives a distance you can size from.
7. Record what happened, by gap type
Two separate tallies: gaps with a reason and gaps without. Combining them produces an average that describes neither.
How to tell it worked
The reason for the gap was written in 1 sentence before any position was taken.
Fade or follow was decided before the open, not after watching it.
0 trades were taken on the opening print, all of them after a range formed.
And the record separates news gaps from no-news gaps, kept over at least 90 days.
Why stops behave differently here
A stop is an instruction to trade at a level, and a gap means no trading happened at that level. The order converts at the open, wherever that is, which can be well beyond where you placed it.
Which makes position size the only real control on overnight risk. No stop placement changes it, and treating a stop as a maximum loss is the assumption that fails on exactly these days.
Why the reason changes the trade
A gap on a scheduled release is a repricing. New information arrived, the market adjusted, and there is no particular reason for it to be undone.
A gap on nothing identifiable is a liquidity artefact. Thin overnight trading moved the price, and there is a reasonable case for it returning once normal volume arrives.
Which is why a single fill statistic across all gaps is close to meaningless. It averages two populations that behave differently, and the average describes neither of them.
Gap size changes the trade
A small gap is often just where overnight trading left the price. It fills readily because there is nothing behind it, and the trade is a short-horizon one with a modest target.
A large gap is a statement. Something moved the instrument enough to reprice it substantially, and the odds of a full return within the session are materially worse.
Measure the gap against the instrument’s ordinary range rather than in percent. On this site’s shared series the median bar range is 0.493 and the ninetieth percentile is 1.101 — a gap smaller than one ordinary bar is a different event from one spanning three.
That ratio is the filter most gap methods are missing. A rule that treats every gap the same is combining a routine overnight drift with a genuine repricing, and no single approach suits both.
The original data
Of the 24,971 unique videos in research/search-study-corpus.jsonl, 45 mention gap trading in the
title, at a median of 12,683 views across 36 channels, and 69% of those titles are instruction-shaped.
The premarket appears in 33 at 3,479 and the market open in 12 at 8,909. The counts come from
site/corpus_count.py.
45 videos at 12,683 across 36 channels. Solid coverage, and almost all of it quotes a single gap-fill percentage without separating the two populations — which is the one distinction that decides whether the statistic applies to the gap in front of you.
The answer to the question on that chart is that an earnings gap is a repricing. The market has new information and has adjusted to it — fading that is betting the adjustment was wrong, which is a much larger claim than the gap-fill statistic supports.
When it fails
The failure is applying a gap-fill statistic to a news gap, and it produces a position against fresh information. The number quoted everywhere is an average across all gaps, most of which are small overnight drifts on nothing. An earnings gap is a different animal: the price moved because what the instrument is worth changed. Fading it on the strength of a statistic derived mostly from the other population is using the right number on the wrong event.
The second failure is trading the opening print. There are no levels yet.
A third is deciding fade or follow after the open. The noise decides.
A fourth is treating a stop as a maximum loss. Gaps go through them.
A fifth is one combined record. It averages two different things.
And a sixth is holding overnight at full size. That is the exposure with no stop.
Related
Gap trading covers the general approach. Gap fill is the statistic and what it actually measures. And gap and go is the continuation version of the trade.
The question I ask first is why, and if I cannot answer it in one sentence I do not take the trade. A gap on an earnings release and a gap on nothing in particular look identical on the chart and are completely different events, and the chart will never tell me which one I am looking at.
— Michael Whitman
This page is educational, not financial advice. Test every idea on your own charts before risking money.