Bonus abuse and latency arbitrage at CFD brokers: commercial problem or reportable suspicion?
Both patterns cost brokers money and both are usually handled under the client agreement. This guide covers what they look like in MT5 and MT4 data, the records needed to test for them, where the line runs between a terms-and-conditions breach and an AML or market-abuse matter, and when an STR may still be warranted.
Reviewed · Educational material, not legal advice.
Two problems that are usually commercial
Bonus abuse exploits a promotion: welcome or deposit bonuses claimed through several accounts, hedged between linked accounts, or unlocked by trading designed only to reach a volume target. Latency arbitrage exploits pricing: trading on the delay between the broker's quotes and faster prices elsewhere.
Check first whether bonuses are allowed at all. Some regulators prohibit them for retail CFD clients; in the UK, COBS 22.5.20R bars firms from offering retail clients monetary or non-monetary incentives for CFDs, with lower fees for all retail clients and information and research tools excluded (COBS 22.5.21G). Where a bonus programme is not permitted, the programme is the compliance issue before any abuse of it.
Bonus abuse patterns
- Multi-accounting: several accounts under different names claim the same welcome bonus, linked by device, IP address, payment instrument or address.
- Hedged bonus accounts: two linked accounts hold opposite positions of the same size. The bonus account absorbs the loss; the other account takes the profit and withdraws. The pairing test is the one used for wash trading.
- Volume to withdraw: short round trips at minimum risk, opened and closed within seconds, until the lot requirement for withdrawing the bonus is met, then little or no trading.
- Bonus cycling: deposit, bonus, minimal trading, withdrawal, repeated across accounts or payment instruments.
- Negative balance: bonus credit used as margin through a volatile event, so that the loss beyond equity is written off.
Latency arbitrage patterns
- Very short holding times, often seconds, with an unusually high share of winning trades.
- Entries just before the broker's quote catches up with a move already visible on faster feeds, concentrated around news and market opens.
- Automated trading (an expert advisor) on a few symbols, many trades per minute, orders clustered at moments when the quote updates.
- Small profit per trade but very consistent; few losing positions held for long.
Data you need
| Record | Source | Used for |
|---|---|---|
| Bonus and credit ledger | Balance and credit operations in MT5 or MT4, campaign records in the CRM | Bonus received, conditions, date met, bonus removed |
| Deals and positions | MT5 deal history (time to the millisecond, position ID, entry or exit) or MT4 trade history | Round trips, holding time, profit per trade, volume against the bonus target |
| Reference prices | Tick data from liquidity providers or an independent feed, with timestamps you trust | Fill price against the market at the same moment; price move after entry |
| Logins | Trading platform and client portal logs: device, IP, platform, expert advisor identifier | Linking accounts; automated trading |
| Funding and withdrawals | Payment records: instrument, payer and payee names | Third-party funds; where profits go |
End-of-day exports are enough for holding times, round trips and bonus tests. Latency tests need tick data.
Tests that separate skill from arbitrage
- Holding-time distribution: the share of a client's profitable positions closed within seconds, compared with other clients on the same symbols. Fix the threshold from your own book, not from a round number.
- Markout: the price move in the client's favour at 1, 5 and 30 seconds after entry, measured on the reference feed. A client who is right at 1 second and flat at 30 seconds is trading your feed, not the market.
- Fill against reference: the gap between the fill price and the reference price at the fill time.
- Bonus economics per linked group: bonus received, combined profit and loss, withdrawals, and the share of volume in opposite pairs inside the group.
- Timing of withdrawal: requests made as soon as a bonus condition is met, or right after a run of short winning trades.
Commercial, market abuse or AML?
| Finding | Usually | Route |
|---|---|---|
| One client, own funds, latency arbitrage | Pricing and contract matter | Client agreement and execution settings. No report by default. |
| Multi-accounting for bonuses, own funds | Fraud against the firm, contract breach | Contract remedies and fraud procedures. |
| Hedged pairs between linked accounts | Contract breach, possibly wash trading | Treat as wash trading; consider a STOR where the regime covers the instrument (DFSA Markets Brief No. 24). |
| Money moved between different people through paired trades or bonus-driven losses | AML | STR or SAR consideration. |
| Third-party deposits, or profits withdrawn to accounts not in the client's name | AML | STR or SAR consideration. |
Market-manipulation texts such as UK MAR Article 12 are about false or misleading signals to a market. Latency arbitrage against a broker's own quotes exploits the broker's pricing rather than signalling to a market. Unless other facts point to manipulation, handle it as a pricing and contract matter, and record that assessment.
When an STR may still be warranted
A commercial label does not switch off the reporting duty. Under Article 18 of Federal Decree-Law No. 10 of 2025, a UAE firm that suspects, or has reasonable grounds to suspect, that funds are proceeds of crime reports to the FIU without delay, regardless of value. Signals that move a bonus or arbitrage case towards an STR:
- Deposits from cards, accounts or wallets in other people's names.
- Value moving from one person to another through paired trades or losses absorbed by bonus accounts.
- Withdrawals to accounts not in the client's name, or to the same destination from several accounts.
- Many accounts funded from one source, each cycling deposit, bonus and withdrawal.
- Accounts opened with documents that appear borrowed or recruited, suggesting money mules.
When the decision is "contract matter only", record why and who decided. When a bonus is removed or profits are voided while an STR is under consideration, keep client messages neutral: disclosing that a report is being considered is an offence under Article 29. The goAML STR filing guide covers the UAE filing, and the MASAK STR guide the Turkish one. For the narrative, follow the CBUAE's section 3.3.
Where Marqib fits
Marqib has a dedicated rule for each. The latency-arbitrage rule rebuilds positions first-in first-out from the trades file and fires when a client has many very short round trips (by default at least 20 in 30 days, each held 10 seconds or less), at least 80% of them profitable, with an average return above that of other clients' round trips in the same instrument. Severity is high when most of the openings follow a sharp price move in the book; the default recommendation is no STR, with a hold on a pending withdrawal when severity is high. The bonus-abuse rule reads an optional file of bonus and credit operations and looks for accounts linked by beneficial owner, payment instrument, bank details, device or IP that both received a bonus and then open opposite positions of similar size in the same instrument within a short time of each other, repeatedly. It holds the winning side's pending withdrawal and recommends reviewing and applying the bonus terms; it recommends an STR when deposits came from payers whose names do not match the account holders. Thresholds are set per firm in the tuning pages.
The third-party funding and pass-through rules cover the other AML signals listed above, and the wash-trading rule covers matched pairs between accounts that share a beneficial owner. The latency rule does not use tick data against a reference feed; its benchmark is the firm's own book.
Sources
- FCA Handbook, COBS 22.5: Restrictions on CFDs for retail clients (incentives: 22.5.20R and 22.5.21G)
- Federal Decree-Law No. 10 of 2025 on AML/CFT, Article 18: Suspicious transaction reporting (CBUAE Rulebook)
- Federal Decree-Law No. 10 of 2025, Article 29: Penalties for disclosure (CBUAE Rulebook)
- CBUAE Rulebook, STR guidance 3.3: Best practices for drafting an STR or SAR
- DFSA Markets Brief No. 24: Suspicious Transaction and Order Reports (October 2021)
- UK MAR (Regulation (EU) No 596/2014 as retained), Article 12: Market manipulation
Questions
Is bonus abuse money laundering?
Usually not. It is fraud against the broker or a breach of the promotion terms. It becomes an AML question when third-party money is involved or value moves between different people.
Is latency arbitrage market abuse?
Market-manipulation rules address false or misleading signals to a market. Arbitrage against a broker's stale quotes exploits the broker's pricing, so it is normally handled as a pricing and contract matter unless other facts point elsewhere.
What holding time counts as short?
No regulator sets one. Compare each client with the distribution of other clients trading the same symbols, and look at markout on a reference feed rather than holding time alone.
Do we need to file an STR when we cancel a bonus?
Not by default. File when the review gives reasonable grounds to suspect that the funds are proceeds of crime, for example third-party deposits or profits sent to other people.
Can bonuses be offered to retail CFD clients?
It depends on the regulator. The FCA prohibits monetary and non-monetary incentives for retail CFD clients under COBS 22.5.20R. Check your own regulator's rules.