Insider Dealing: Why That Stock Moved Before the News

My apprentice once accused an entire earnings calendar of being rigged against him personally, which felt like an ambitious claim for one twenty-three-year-old to make against the global financial system before lunch. If you have ever watched a stock — or a CFD tracking one — drift suspiciously in the "right" direction hours before an announcement, you have felt the same suspicion. Insider dealing is the word that comes to mind. It is usually the wrong one.

This post covers what insider dealing actually requires under UK law, the legal mechanics that produce eerily well-timed pre-news moves without anyone breaking a single rule, and — because this matters — when the concern is genuinely worth taking seriously. If you came here hoping I would tell you the whole market is a stitch-up, I would rather correct that now than six paragraphs in.

You watched the move happen before the headline did

Here is a version of this a lot of CFD and share traders have lived through. You had confluence — a clean technical level, a sensible reason to be there, nothing reckless about the setup. You pulled the trigger ahead of an earnings release, and in the hours before the number actually printed, price started drifting. Not wildly. Persistently, in the direction the announcement later confirmed. The headline landed. The move was already mostly done, and your entry looked amateur next to it.

My analysis was right but I still lost feels different when the reason is not a stop hunt or a bad read on structure, but the creeping sense that someone, somewhere, already had the number before you did. Sure, heard that before — every retail trader eventually decides the market is rigged against them personally at some point, usually around 11pm on a losing week. Except this particular suspicion is worth taking seriously enough to actually check, rather than either dismissing it or assuming the worst. The honest answer sits between "nothing to see here" and "everyone already knew."

What insider dealing actually requires, legally

Under FCA guidance on inside information, information only qualifies if it has not been made public, relates directly or indirectly to a specific issuer or instrument, and would be likely to have a significant effect on the price if it became public. It also has to be precise — describing something that exists or can reasonably be expected to happen, not a hunch, a vibe, or a forum post from someone who "knows a guy."

(Yes, I know how that sounds — like a lawyer's technicality designed to let people off the hook. It is the opposite. That precision is exactly why most pre-news drift does not qualify, and why the market is not nearly as riddled with genuine market abuse as it feels like from the outside.)

Under UK MAR, insider dealing is a civil offence, and under the Criminal Justice Act 1993 it can also be prosecuted criminally, with sentences reported at up to seven years and FCA materials referencing penalties of up to ten years alongside an unlimited fine. This is not a minor administrative rule. It is treated, correctly, as a serious financial crime — which is exactly why the legal bar for proving it is narrow rather than broad.

Photo by Rafael Minguet Delgado on Pexels

The legal mechanics that look exactly like cheating

Three genuinely legal mechanisms explain most of what people mistake for insider dealing.

• →Options market maker hedging — as traders build option positions ahead of a known earnings date, the market makers on the other side hedge their exposure by buying or selling the underlying stock, which can create a directional drift entirely from public order flow.
• →Unusual options volume — publicly visible on most data feeds, and entirely legal for anyone to trade on, even though it can look suspicious in hindsight once the news confirms the direction.
• →Aggregated analyst expectations — consensus estimates and "whisper numbers" built from publicly available research, which can move price ahead of a release without a single person holding actual inside information.

None of these require anyone to know the number early. They just require enough public participants positioning on probability, which produces a drift that looks, from the outside, exactly like someone already knew.

A worked example: a large-cap stock has an earnings date everyone can see on a public calendar. Options volume in the days beforehand runs well above average, all of it visible on standard data feeds, none of it inside information — just traders with a view, expressed publicly, in size. Market makers on the other side of that volume hedge their book by trading the underlying stock, and that hedging flow, not a leak, is what shows up as a directional drift on your chart. Rinse, repeat, every earnings season, on nearly every liquid name.

Structure, not conspiracy

I have watched my apprentice go from "this is definitely illegal" to "oh, that is just gamma hedging" over the course of one conversation, and the change in his mood was noticeable. The market is not chaotic here, and it is not a conspiracy either. It has a repeatable, learnable structure — the same structure this entire site is built on explaining — and pre-news drift is one more example of institutional order flow that is predictable once you know what to look for, not evidence of cheating.

I can find this on YouTube for free — largely true for the legal definitions, less true for anyone connecting those definitions specifically to why your CFD position drifted before an earnings headline. Most explainers cover the crime. Fewer explain the mechanism that gets mistaken for it.

Photo by SHVETS production on Pexels

When it actually is insider dealing, and who should worry

This is not legal advice, and nothing here should be treated as a substitute for it. But it is worth being plain about where the genuine risk sits, because most of it has nothing to do with reading a chart.

If you work at, or are closely connected to, a company whose shares or CFDs you also trade, and you come into possession of specific, non-public information about that company — a merger before it is announced, numbers before they are published, a regulatory decision before it is public — trading on that, encouraging someone else to trade on it, or passing it along is the genuine risk this law exists for. CFDs on shares are treated the same as the underlying share for this purpose; the instrument does not change the legal question, the information does.

If none of that applies to you — if your read comes from public price action, public options data, or a genuinely public news feed, however good your timing looks in hindsight — you are trading probability, not information, and that is precisely what risk management and structural reading are for. The suspicion is understandable. The mechanism behind it, once you see it, stops feeling personal.

There is a genuine difference between being early and being illegal, and it is worth sitting with that distinction rather than assuming the worst about either yourself or the market every time a setup gets beaten by a headline. If a specific tip from a specific person at a specific company is involved, that is a conversation for a solicitor, not a chart. If it is public data, public flow, and a public calendar, the only thing you actually got wrong was assuming the drift meant a leak instead of a mechanism.