{"id":4226,"date":"2026-10-22T11:37:10","date_gmt":"2026-10-22T15:37:10","guid":{"rendered":"https:\/\/hftarbitrageplatform.com\/?p=4226"},"modified":"2026-10-22T11:37:13","modified_gmt":"2026-10-22T15:37:13","slug":"%e7%bb%8f%e7%ba%aa%e4%ba%ba%e5%a6%82%e4%bd%95%e6%a3%80%e6%b5%8b%e5%bb%b6%e8%bf%9f%e5%a5%97%e5%88%a9","status":"publish","type":"post","link":"https:\/\/hftarbitrageplatform.com\/zh\/how-brokers-detect-latency-arbitrage\/","title":{"rendered":"\u7ecf\u7eaa\u4eba\u5982\u4f55\u68c0\u6d4b\u5ef6\u8fdf\u5957\u5229\uff1a\u4fe1\u53f7\u3001\u5347\u7ea7\u68af\u7ea7\u4ee5\u53ca\u4ea4\u6613\u8005\u6240\u770b\u5230\u7684"},"content":{"rendered":"\n

Almost every latency arbitrage account goes the same way. The first weeks look great: fills are clean, trades last a few seconds, and the equity curve climbs at a steady angle. Then, with no email and no warning, things change. Fills start slipping by half a pip, and always against you. Orders that used to fill in 40 ms now take 300 ms. Spreads on the account look a little wider than the broker’s published ones. A few weeks later compliance writes to say a “trading activity review” is under way.<\/p>\n\n\n\n

None of that is bad luck. It is a detection system doing its job. This guide explains how brokers detect latency arbitrage<\/strong> from the trader’s side of the screen: which numbers the risk team actually computes, why arbitrage flow stands out so clearly in them, the usual escalation ladder after an account is flagged, and how to read your own trade log to see whether it has already happened to you.<\/p>\n\n\n\n

If you are new to the strategy itself, start with our explanation of how latency arbitrage works<\/a>. This article assumes you know the basic idea: trading a slow quote against a faster reference feed.<\/p>\n\n\n\n

Why brokers look for latency arbitrage in the first place<\/h2>\n\n\n\n

Detection follows the money. A broker that hedges every trade with a liquidity provider (a pure A-book) is mostly indifferent to your strategy, though its LP may not be, because the LP ends up holding the stale-price loss. A broker that takes the other side of client trades (B-book, or hybrid) books every arbitrage profit as its own loss. One fast account can wipe out the spread income from hundreds of ordinary clients.<\/p>\n\n\n\n

So the question a risk team asks is not really “is this arbitrage?” but “is this flow toxic to my book?” Toxic flow means trades that consistently know where the price is going next. Latency arbitrage is the cleanest example of it, which is why it is so easy to measure. For the routing side of this story, see our breakdown of A-book vs B-book brokers<\/a>.<\/p>\n\n\n\n

The single most important metric: markout<\/h2>\n\n\n\n

If a broker’s risk team could look at only one number, it would be markout<\/strong>: how far the market moves in your favour in the short window after each fill. The broker takes the mid price at the moment of your fill, then again 100 ms, 500 ms, 1 s and 5 s later, and averages the difference across all your trades.<\/p>\n\n\n\n

For an ordinary retail client that average sits near zero, or below it once spread is included. Retail traders are, on average, not able to predict the next second of price action. A latency arbitrage account looks completely different. Its trades exist because<\/em> the price is about to move, so the markout curve jumps up almost at once and then flattens. That shape is very hard to produce by accident.<\/p>\n\n\n\n

\n\n\nAverage markout after the fill (illustrative)<\/text>\nMid-price move in the trader’s favour, measured from the fill time<\/text>\n\n\n\n\n\n0<\/text>\n+0.4<\/text>\n+0.8<\/text>\n+1.2 pip<\/text>\nfill<\/text>\n100 ms<\/text>\n500 ms<\/text>\n1 s<\/text>\n2 s<\/text>\n5 s<\/text>\n\n\n\narbitrage flow: ~+1 pip within 0.5 s<\/text>\nordinary retail flow: ~0<\/text>\nThe gap between the two curves is what a risk engine scores. Numbers are illustrative, not from a specific broker.<\/text>\n<\/svg>\n
Markout is the fingerprint: arbitrage trades are “right” within milliseconds, ordinary trades are not.<\/figcaption>\n<\/figure>\n\n\n\n

Markout is powerful because it ignores your story. It does not care whether you call your system a scalper, a news trader or a grid. It measures only whether your fills are systematically ahead of the price, and that is precisely the edge latency arbitrage relies on.<\/p>\n\n\n\n

The other signals risk engines combine<\/h2>\n\n\n\n

Markout alone can throw false positives. A skilled news trader will sometimes produce a positive markout too. So modern risk tools combine it with a handful of behavioural features. None of these proves arbitrage on its own. Together they make a very confident score.<\/p>\n\n\n\n

\n\n\n\n
Signal<\/th>What it measures<\/th>Why arbitrage stands out<\/th>What you’d see in your own log<\/th><\/tr><\/thead>\n
Markout<\/strong><\/td>Price move in your favour 0.1-5 s after the fill<\/td>Trades are opened because the move is already under way<\/td>Most trades are in profit within a second<\/td><\/tr>\n
Hold-time distribution<\/strong><\/td>How long positions stay open<\/td>Tight cluster of seconds, not a spread of minutes to days<\/td>Median hold time in single-digit seconds<\/td><\/tr>\n
Win rate by hold time<\/strong><\/td>Win rate on very short trades specifically<\/td>Short trades are normally a coin flip minus the spread; arbitrage wins most of them<\/td>High win rate concentrated on the fastest trades<\/td><\/tr>\n
Order timing vs ticks<\/strong><\/td>Delay between a price update on a reference market and your order<\/td>Orders arrive in a narrow window right after external moves, before the broker’s own quote catches up<\/td>Entries bunched around fast moves and news spikes<\/td><\/tr>\n
Slippage asymmetry<\/strong><\/td>Ratio of positive to negative slippage<\/td>Once an account is flagged, the broker controls this ratio, so it’s also an outcome<\/td>Positive slippage disappears, negative slippage grows<\/td><\/tr>\n
Sizing and pattern regularity<\/strong><\/td>Repeated lot sizes, symbols, session times<\/td>Bots repeat themselves; humans drift<\/td>Same lot on nearly every trade, same few symbols<\/td><\/tr>\n
Cross-account links<\/strong><\/td>Shared IPs, devices, mirrored or opposite P&L<\/td>Two-leg and multi-account set-ups leave correlated footprints<\/td>Not visible to you, but it is checked<\/td><\/tr>\n<\/tbody><\/table>\n<\/figure>\n\n\n\n

From rules to models<\/h3>\n\n\n\n

Early detection was a set of hard rules: “flag any account with an average hold time under N seconds and a win rate over X%.” Rules like that are easy to step around and they catch plenty of innocent scalpers. Most serious brokers and their technology vendors now feed the features above into a scoring model that ranks accounts by toxicity, often refreshed daily or even intraday. The practical effect is that no single threshold exists to stay under. The model weighs the whole profile, and the profile of a pure latency strategy is distinctive.<\/p>\n\n\n\n

\n\n\nInside a broker’s toxic-flow pipeline<\/text>\n\nRaw data<\/text>\nyour orders & fills<\/text>\nbroker quote ticks<\/text>\nreference LP feed<\/text>\nlogin IP \/ device<\/text>\nlinked accounts<\/text>\n\nFeatures<\/text>\nmarkout 0.1 \/ 0.5 \/ 1 \/ 5 s<\/text>\nhold-time distribution<\/text>\nwin rate on short trades<\/text>\norder-to-tick timing<\/text>\nP&L correlation<\/text>\n\nToxicity<\/text>\nscore<\/text>\n\nlow: no action<\/text>\n\nmid: watchlist<\/text>\n\nhigh: act<\/text>\n\n\n\n\n\n\n\nThe model scores the whole profile, so there is no single “safe” number to stay under.<\/text>\nScores are typically refreshed daily or intraday, so flags can appear weeks after an account opens.<\/text>\n<\/svg>\n
Simplified view of how trade data becomes a toxicity score and then an action.<\/figcaption>\n<\/figure>\n\n\n\n

What happens after an account is flagged<\/h2>\n\n\n\n

Brokers rarely close an account the moment it is flagged. Closing is the loudest option and it ends the spread income too. What usually happens is a quiet escalation, each step designed to take the edge away while the account keeps trading. Knowing the ladder matters, because each rung leaves a visible trace in your results.<\/p>\n\n\n\n

\n\n\nThe usual escalation ladder (and what you see)<\/text>\n\n1. Watchlist<\/text>\nnothing visible yet<\/text>\n\n2. Execution changes<\/text>\nslower fills, one-way slippage<\/text>\n\n3. Pricing changes<\/text>\nwider spread, more rejects<\/text>\n\n4. Account action<\/text>\nreview, limits, closure<\/text>\n\n\n\nEdge left:<\/text>\n\n\n\n\nstep 1<\/text>\nstep 2<\/text>\nstep 3<\/text>\nstep 4<\/text>\nNot every broker uses every step, and the order can differ. Profit reviews usually rely on the client agreement’s abusive-trading clause.<\/text>\n<\/svg>\n
Most accounts lose their edge at steps 2 and 3, long before anyone writes to them.<\/figcaption>\n<\/figure>\n\n\n\n

Step 2: execution changes<\/h3>\n\n\n\n

The account is moved to a different execution group. Orders may be held for a short delay before they are filled. A delay of even a hundred milliseconds is enough to erase an edge that lives in the first few hundred. Slippage becomes one-way: when the price moves against you during the delay you get the worse price, and when it moves for you the order is filled at the requested price or rejected. This is what a “virtual dealer” set-up does, and it is the most common response by far.<\/p>\n\n\n\n

Step 3: pricing changes<\/h3>\n\n\n\n

Next the account may get a wider spread markup than the published one, a slower or smoothed price feed, or a last-look window in which the broker or its LP can reject fills that have become unprofitable for them. On paper your strategy still “works”; in practice the expected value per trade falls to around zero.<\/p>\n\n\n\n

Step 4: account action<\/h3>\n\n\n\n

Finally comes the visible step: a trading review, reduced leverage, a block on certain instruments, a closed account, or, in the worst case, cancelled profits under an “abusive trading” or “price latency exploitation” clause in the client agreement. Read that clause before you deposit, because it decides whether a dispute is even worth having.<\/p>\n\n\n\n

How to tell if your account has already been flagged<\/h2>\n\n\n\n

Brokers don’t announce steps 1 to 3, but you can measure them. You have the same data they do for your own trades. Run this check every week:<\/p>\n\n\n\n

    \n
  1. Compare execution time over time.<\/strong> Export order-sent and order-filled timestamps. If your median fill time jumps from tens of milliseconds to hundreds, and the jump is not explained by your VPS or network, the account was most likely moved.<\/li>\n
  2. Count positive versus negative slippage.<\/strong> On a fair account both happen. If positive slippage drops to almost nothing while negative slippage grows, the execution is asymmetric.<\/li>\n
  3. Track profit per trade, not just win rate.<\/strong> A falling average profit with an unchanged signal count means the edge is being taxed somewhere between your order and the fill.<\/li>\n
  4. Watch the reject and requote rate.<\/strong> A sudden rise in “off quotes” or “price changed” errors on fast moves is the classic last-look footprint.<\/li>\n
  5. Compare the account’s spread to the published spread.<\/strong> Log the bid\/ask at entry. A persistent extra fraction of a pip is a markup, not market conditions.<\/li>\n<\/ol>\n\n\n\n

    Any one of these can be noise. Two or three together, starting in the same week, are a strong sign that the account has climbed the ladder. The rational move then is usually not to fight the broker but to withdraw and redeploy.<\/p>\n\n\n\n

    What this means for anyone running arbitrage<\/h2>\n\n\n\n

    Detection is not a reason to give up on latency arbitrage. It is a reason to run it as a professional operation and not a lottery ticket. In practice that means:<\/p>\n\n\n\n