# Dealing-Desk Intervention > Broker-side software or manual control that alters how client orders are handled between receipt and fill — added delay, requote thresholds, asymmetric slippage tolerance — on platforms where the broker is the counterparty to the trade. - Canonical: https://hadalinstruments.com/glossary/dealing-desk-intervention/ - Term set: https://hadalinstruments.com/glossary/ --- On a dealing-desk (B-book) platform the broker does not route the client's order to an external market; it takes the other side. Internalisation is not inherently abusive — it is how much of retail FX and CFD trading is served at all, and a broker that hedges its net book can be economically neutral to client outcomes. But the structure creates a standing conflict: on the unhedged portion of the book, the client's loss is the broker's gain, and the broker also operates the software that decides how the client's orders are executed. Dealing-desk intervention is the exercise of that position. The tooling is documented rather than hypothetical: server-side plugins for the dominant retail platforms — sold openly under names like "virtual dealer" — allowed brokers to configure, per client group, execution delays, [requote](/glossary/requote/) thresholds, and slippage rules. Regulatory actions against US retail FX brokers in the early 2010s documented the abusive configuration specifically: slippage applied asymmetrically, so that price improvement during the delay was kept by the broker while price deterioration was passed to the client. The delay itself is the enabling primitive — a manufactured [last look](/glossary/last-look/) window in which the market's drift can be observed before the fill is priced. The operative fact for traders is that intervention is invisible in any single trade and statistical in aggregate. A delayed fill looks like latency; an asymmetric slippage rule looks like bad luck — once. Across hundreds of executions, the signatures separate cleanly from noise: execution-delay distributions with structure that infrastructure cannot explain, [slippage](/glossary/slippage/) asymmetry conditioned on interim drift, requote clustering around the moments discretion is most valuable, and feed behaviour like [censoring](/glossary/censoring/) around the same windows. None of this requires access to the broker's server. The broker's own execution records, timestamped and compared against an independent reference feed, carry the fingerprint — or its absence. ## Commonly confused with Neighbouring concepts that get used interchangeably, and the distinction that actually separates them. - **B-book internalisation** — Internalisation is the structure — the broker takes the other side rather than routing out. It is not inherently abusive; it is how much of retail FX and CFD trading is served at all, and a broker that hedges its net book can be economically neutral to client outcomes. Intervention is what happens when the party holding that position also configures the execution software. - **Latency** — A delayed fill looks like latency, and once, it is indistinguishable from it. The difference is that infrastructure delay has no reason to correlate with which way the market drifted during the delay. Structure that infrastructure cannot explain is the finding. - **[Last look](https://hadalinstruments.com/glossary/last-look/)** — Last look is a disclosed hold window in over-the-counter FX. An added execution delay on a dealing-desk platform is a manufactured version of the same primitive — an interval in which the market's drift can be observed before the fill is priced. - **Bad luck** — An asymmetric slippage rule looks like bad luck exactly once. Across hundreds of executions the signatures separate cleanly from noise, which is why this is a statistical question rather than a grievance about a particular trade. ## How to measure it in your own data A definition you cannot test is a definition you have to take on trust. This is the shortest honest route from the concept to a number you computed yourself. - **Records you need** — Your broker's own execution records — order and fill timestamps, requested and filled prices, requotes and rejections — compared against an independent reference feed over the same windows. None of this requires access to the broker's server. - **What you compute** — Execution-delay distributions checked for structure infrastructure cannot explain; slippage asymmetry conditioned on interim drift; requote clustering around the moments discretion is most valuable; and feed behaviour such as censoring across the same windows. - **What the answer tells you** — Intervention is invisible in any single trade and statistical in aggregate — that is the whole shape of the problem. The specific abusive configuration documented in regulatory actions against US retail FX brokers in the early 2010s was asymmetric slippage: price improvement during the delay kept by the broker, price deterioration passed to the client. The records carry that fingerprint, or its absence, and the absence is worth establishing too. ## Questions and answers ### Does a dealing-desk broker profit when I lose? On the unhedged portion of its book, yes — that is the standing conflict, and it is structural rather than an accusation. A broker that hedges its net exposure can be economically neutral to your outcomes. The difficulty is that the same party also operates the software deciding how your orders are executed. ### Is this tooling actually real? Dealing-desk intervention tooling is documented rather than hypothetical. Server-side plugins for the dominant retail platforms were sold openly — under names like "virtual dealer" — allowing brokers to configure execution delays, requote thresholds and slippage rules per client group. The existence of the capability is not in dispute; how any particular broker configured it is the measurable question. ### How would I detect intervention in my own trading? By aggregate structure rather than by individual trades. Look for execution-delay distributions with shape that infrastructure cannot account for, slippage asymmetry conditioned on which way the market moved during the delay, and requotes clustering where discretion is most valuable. Compare against an independent reference feed for the same windows. ### Why is the delay the important part? Because it is the enabling primitive. An interval between receiving an order and pricing the fill is an interval in which the market's drift can be observed — which converts a neutral execution step into an option. Everything else, including asymmetric slippage rules, is built on top of having that window. ## If this has already cost you Execution-delay structure and slippage asymmetry are statistical properties of your own records, and they need no access to anyone’s server. - [Execution-Chain Attribution](https://hadalinstruments.com/assays/#execution-chain-attribution) “Was it the EA, the connection, or the broker?” Will not establish: Fault. The chain attribution shows where the divergence entered, not who owes you for it — a wide fill can be an honest market, a slow hop can be your own VPS, and the report distinguishes what the logs prove from what they merely suggest. - [Feed Fidelity Assay](https://hadalinstruments.com/assays/#feed-fidelity-assay) “Is the feed my terminal shows me behaving consistently?” Will not establish: A verdict on your broker. One exported log from one terminal measures your feed as you received it — venue-side behaviour, other account tiers and intent are all outside what this data can carry. Intake is not open yet, so none of these can be commissioned today. They are listed here so you know the measurement exists and what it would and would not settle — the [launch list](https://hadalinstruments.com/pricing/#waitlist) hears first. ## Related terms Derived from the links this entry makes and the entries that link back to it. - [Censoring](https://hadalinstruments.com/glossary/censoring/) The thinning of a price feed — updates dropped, coalesced or rate-limited — during the intervals in which the underlying market is moving fastest, so that the record understates the spread widening and depth withdrawal that actually occurred. - [Last Look](https://hadalinstruments.com/glossary/last-look/) A practice in over-the-counter foreign exchange in which a liquidity provider, after receiving an order against its quoted price, retains a final window in which to accept or reject the trade. - [Liquidity Provider](https://hadalinstruments.com/glossary/liquidity-provider/) A participant that quotes two-sided prices and stands ready to trade against incoming orders, compensated by the spread for carrying inventory risk and adverse-selection risk. - [Requote](https://hadalinstruments.com/glossary/requote/) A venue's response to an order that offers a new price instead of a fill, obliging the trader to accept the revised price, retry, or abandon the trade. - [Slippage](https://hadalinstruments.com/glossary/slippage/) The difference between the price at which a trade was expected to execute and the price at which it actually filled, signed so that positive slippage favours the trader and negative slippage costs them. ## In the research Dealing-Desk Intervention comes up in one research note on this site. - [Is my broker trading against me?](https://hadalinstruments.com/research/is-my-broker-trading-against-me/) As asked it is unfalsifiable. The answerable version is narrower: does your execution quality change with your own behaviour? Here is how to record that. ## Cite This Definition APA BibTeX HTML Hadal Instruments. (2026). Dealing-Desk Intervention. Hadal Glossary. https://hadalinstruments.com/glossary/dealing-desk-intervention/ Version 2b360a7, 2026-08-28. @misc{hadal_2026_dealing-desk-intervention, author = {Hadal Instruments}, title = {Dealing-Desk Intervention}, year = {2026}, url = {https://hadalinstruments.com/glossary/dealing-desk-intervention/}, howpublished = {Hadal Glossary}, version = {2b360a7}, note = {Pre-launch publication; version dated 2026-08-28} } Source: Hadal Instruments, Dealing-Desk Intervention. Original Research Copy Citation **Version 2b360a7** identifies the commit that last changed this page in Hadal's content repository. That repository is not public, so the identifier does not resolve externally — it is published so a citation pins one specific state rather than a moving page. To obtain the exact version cited, use the [press and research route](https://hadalinstruments.com/press/).