Detecting Coordination Risk among AI Trading Agents: Integrating Communication and Behavioral Evidence for Financial Auditing
XIE Tengda, DU Yunhao · Team AI Auditing
Submitted to AI Collusion Research Sprint. Sprint projects are early-stage work by participants, not Apart Research publications.
This study develops and evaluates an audit-oriented framework for detecting coordination risk among artificial-intelligence trading agents. The framework integrates non-semantic communication structure with behavioral alignment residualised against observable market-wide and common-shock conditions. The experiment uses a rule-based synthetic data-generating process rather than a reinforcement-learning model: coordinated sets, activity periods, and labels are specified for evaluation. Four scenarios represent independent activity, explicit coordination, weak and intermittent coordination, and a no-coordination common-shock counterfactual. Across 120 runs, five agents, and 500 periods per run, the integrated logistic model achieved a mean ROC AUC of 0.852 and an F1 score of 0.684 under repeated run-grouped holdouts. A common-shock ablation reduced ROC AUC to 0.737 and F1 to 0.584, showing that raw synchrony alone is not an adequate audit signal. A nested threshold procedure targeting a 10% G4 false-positive rate produced a mean out-of-sample G4 rate of 0.092. Semi-synthetic analysis using public daily Fama-French factor backgrounds yielded an ROC AUC of 0.844 and an F1 score of 0.697, but it does not constitute real-world validation. The proposed output is therefore a transparent referral score for human review rather than a finding of unlawful conduct.
Reviews
A clean, reproducible ML workflow: run-grouped splits, nested threshold selection, calibration metrics and a common-shock counterfactual. I ran the scripts and the performance and threshold tables reproduced exactly. The main limitation is that the "AI trading agents" are rule-based, not learning or LLM agents, so the study measures how well a classifier recovers signals the simulator plants. For example, G2 coordinating agents get extra within-set messages, which the message-rate features can pick up, and the "shock-controlled" alignment feature is residualised on the simulator's exact common-shock series, which a real auditor could only estimate. To strengthen it: use LLM or RL agents, estimate the common factor from observable market data, and test against coordination mechanisms the features weren't designed around. The report is 13 pages and its first 8 include a title page and table of contents; shortening the literature review would bring the results forward.
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Cite this project
@misc{tengda2026detecting,
title = {{Detecting Coordination Risk among AI Trading Agents: Integrating Communication and Behavioral Evidence for Financial Auditing}},
author = {XIE Tengda and DU Yunhao},
year = {2026},
month = oct,
note = {Submitted to AI Collusion Research Sprint, an Apart Research Sprint},
howpublished = {\url{https://apartresearch.com/sprints/projects/detecting-coordination-risk-among-ai-trading-agents-integrating-communication-and-behavioral-evidence-for-financial-auditing-gvyx}},
url = {https://apartresearch.com/sprints/projects/detecting-coordination-risk-among-ai-trading-agents-integrating-communication-and-behavioral-evidence-for-financial-auditing-gvyx}
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