Coinbase AI Agent Cuts Fraud by 30% in Onramp Experiment

Coinbase has fine-tuned an open-weight AI model on its proprietary transaction data to outperform a leading closed-source model in fraud detection, with better detection scores and lower serving latency. In a three-part technical series, the exchange argued that companies can get better results from specialized models trained for their own needs than from relying on increasingly capable general-purpose AI systems. In an October 12 post, Coinbase CEO Brian Armstrong explained that the company has fine-tuned Qwen3.5-9B using internal data and found that it “outperformed frontier models, at much lower cost and speed,” on the specialized task of fraud prevention.