Function 5 · financial crime

Do the monitoring rules find the planted typologies, and which alert should an investigator open first?

Four rules at the reporting threshold's boundary fired 649 alerts over three years, 7.9 per hundred thousand ledger entries, and found 362 of the 422 complete planted episodes. Structuring carries the workload: cash intensive businesses make 376 of its alerts and only 41.5% are real. The triage model orders the queue, and in the last two months every real alert sits above every lookalike. Nothing here is a suspicious activity finding, and no report is filed anywhere.

Alerts, all rules
649
About 18.0 a month
Planted episodes found
362 of 422
Recall 85.8%
Structuring alerts that are real
41.5%
Recall 76.5%
Triage AUROC, test months
1.000
A property of the generator; see the report

The investigator's view: alerted communities in the transfer network

The 43,318 accounts that pay other customers fall into 9,263 separate groups, mostly small circles of friends and family, and Louvain finds no finer structure inside any of them, so each group is one community. 12 of the 15 planted rings sit whole inside one community, and the round tripping rule fired on members of 10 of them, every ring with a trip that posted in full. Mule accounts show as stars: many outside senders, one wire out.

  • Alerted account (outlined)
  • Planted ring member the round tripping rule found
  • Outside party
  • Colour: the three most suspicious communities; grey, every other

Source: generated, Harborline deposit accounts and their entries, September 2023 to August 2026, seed 20260831, as of 2026-08-31.

What each rule finds, against the planted truth

RuleAlertsPrecisionComplete episodesFoundRecallPosted in partAlerts per 100k entries
Structuring37641.5%20415676.5%04.57
Rapid movement100100.0%100100100.0%01.22
Round tripping90100.0%2424100.0%191.09
Mule fan in83100.0%948287.2%01.01
The four rules fired 649 alerts, 7.9 per hundred thousand ledger entries, and found 362 of 422 complete planted episodes. Structuring is where the work is: 41.5% of its alerts are real, because cash intensive businesses deposit just under the threshold for honest reasons. The other three rules fired no false alerts on this generator, which a real program should not expect.

Source: generated, Harborline deposit accounts and their entries, September 2023 to August 2026, seed 20260831, as of 2026-08-31.

Alerts by month and rule

0510152023-092024-022024-072024-122025-052025-102026-032026-08Month the alert closedStructuringMule fan inRapid movementRound tripping

Alerts

About 18.0 alerts a month, 32 in the busiest, 2024-04. That is the queue an investigator team is staffed for, and the triage order decides which of them is opened first.

Source: generated, Harborline deposit accounts and their entries, September 2023 to August 2026, seed 20260831, as of 2026-08-31.

The case queue, 2026-06-28 to 2026-08-27

30 alerts in the order the triage model sets. The last column is the generator's truth, which an investigator would never see; it is here so you can check the order.

#RuleAccountClosedAmountTriageWhat firedTruth
1StructuringA00716212026-07-10$53,7161.0006 cash deposits between $8,000 and $10,000 within 10 days, $53,716 in all▲ planted
2StructuringA00484812026-07-22$53,8821.0006 cash deposits between $8,000 and $10,000 within 10 days, $53,882 in all▲ planted
3Rapid movementA00352472026-07-12$118,0351.000$118,035 arrived by wire and $108,389 left within 24 hours▲ planted
4StructuringA00546632026-07-22$35,5630.9994 cash deposits between $8,000 and $10,000 within 10 days, $35,563 in all▲ planted
5StructuringA00122182026-07-12$35,7040.9994 cash deposits between $8,000 and $10,000 within 10 days, $35,704 in all▲ planted
6StructuringA00525752026-07-28$35,3190.9994 cash deposits between $8,000 and $10,000 within 10 days, $35,319 in all▲ planted
7StructuringA00183202026-07-21$54,6850.9996 cash deposits between $8,000 and $10,000 within 10 days, $54,685 in all▲ planted
8Rapid movementA00444092026-07-23$68,8060.999$68,806 arrived by wire and $62,597 left within 24 hours▲ planted
9StructuringA00525632026-07-15$54,3100.9996 cash deposits between $8,000 and $10,000 within 10 days, $54,310 in all▲ planted
10Mule fan inA00309982026-07-22$24,1990.999Payments in from 16 unrelated senders within 14 days, then $21,817 out in one transfer▲ planted
11StructuringA00207582026-07-03$26,9890.9983 cash deposits between $8,000 and $10,000 within 10 days, $26,989 in all▲ planted
12StructuringA00301122026-07-20$27,6030.9973 cash deposits between $8,000 and $10,000 within 10 days, $27,603 in all▲ planted
13Mule fan inA00324722026-08-05$14,8030.995Payments in from 12 unrelated senders within 14 days, then $21,663 out in one transfer▲ planted
14StructuringA00240742026-07-26$26,8250.9923 cash deposits between $8,000 and $10,000 within 10 days, $26,825 in all▲ planted
15StructuringA00153252026-07-01$25,9390.9893 cash deposits between $8,000 and $10,000 within 10 days, $25,939 in all▲ planted
16StructuringA00262722026-08-27$26,8040.1563 cash deposits between $8,000 and $10,000 within 10 days, $26,804 in alllookalike
17StructuringA00013202026-08-05$27,8080.0893 cash deposits between $8,000 and $10,000 within 10 days, $27,808 in alllookalike
18StructuringA00036622026-07-03$25,7050.0333 cash deposits between $8,000 and $10,000 within 10 days, $25,705 in alllookalike
19StructuringA00776482026-08-23$34,9130.0324 cash deposits between $8,000 and $10,000 within 10 days, $34,913 in alllookalike
20StructuringA00443162026-07-21$25,7820.0323 cash deposits between $8,000 and $10,000 within 10 days, $25,782 in alllookalike
21StructuringA00466492026-08-11$26,2980.0183 cash deposits between $8,000 and $10,000 within 10 days, $26,298 in alllookalike
22StructuringA00054802026-07-06$25,8840.0173 cash deposits between $8,000 and $10,000 within 10 days, $25,884 in alllookalike
23StructuringA00525482026-07-04$26,8240.0103 cash deposits between $8,000 and $10,000 within 10 days, $26,824 in alllookalike
24StructuringA00760822026-08-05$25,5580.0083 cash deposits between $8,000 and $10,000 within 10 days, $25,558 in alllookalike
25StructuringA00392282026-06-28$25,8740.0073 cash deposits between $8,000 and $10,000 within 10 days, $25,874 in alllookalike
26StructuringA00780522026-07-19$25,4030.0043 cash deposits between $8,000 and $10,000 within 10 days, $25,403 in alllookalike
27StructuringA00728002026-08-25$25,8030.0023 cash deposits between $8,000 and $10,000 within 10 days, $25,803 in alllookalike
28StructuringA00392282026-08-09$26,5230.0023 cash deposits between $8,000 and $10,000 within 10 days, $26,523 in alllookalike
29StructuringA00780652026-08-26$25,2900.0013 cash deposits between $8,000 and $10,000 within 10 days, $25,290 in alllookalike
30StructuringA00246012026-07-21$25,7950.0003 cash deposits between $8,000 and $10,000 within 10 days, $25,795 in alllookalike

The communities with planted accounts

CommunityAccountsAlertsShare alertedPlanted accountsRules firedMoney inside
0251520.0%5round_tripping$730,800
11141228.6%4round_tripping$493,756
1015426.7%4round_tripping$269,814
320820.0%4round_tripping$431,068
222818.2%4round_tripping$272,630
1231617.4%4round_tripping$613,443
1311927.3%3round_tripping$300,847
917617.6%3round_tripping$257,653

Source: generated, Harborline deposit accounts and their entries, September 2023 to August 2026, seed 20260831, as of 2026-08-31.

Method and limitations

  • The typologies and their lookalikes are generated, and the rules are graded against the generator's truth. A real program learns from investigator dispositions, which are noisier and arrive weeks later.
  • Three of the four rules fired no false alerts here. The generator's lookalikes for rapid movement and mule fan in do not look enough like the real thing, which a real program's rules would not be so lucky with.
  • Recall counts only episodes whose every entry posted; 19 round trips posted with a hop missing and are counted beside it.
  • Cases on this page are a ranked list. The API opens, updates and audits cases for the fraud desk's alerts; monitoring alerts are not wired into it.