A CFA Charterholder Built an ML Fraud Detector: Here's What the Models Miss
Note (2026-03-19): This was an early exploration in my AI security research. The methodology has known limitations documented in the quality assessment. For the current state of this work, see Multi-Agent Security and Verified Delegation Protocol. I’m a CFA charterholder who builds ML systems. I trained XGBoost on 100K financial transactions to detect fraud — AUC 0.987. But the most interesting finding wasn’t the model performance. It was that CFA-informed rule-based scoring achieves 0.898 AUC on its own, and 8 of the top 20 predictive features come from domain expertise, not raw data. ...