Thomson 1: The New $40M Legal AI Model | Thomson Reuters Joel Hron

Joel Hron, CTO of Thomson Reuters, breaks down how the 175-year-old company trained its own legal AI model, Thomson, for around $40 million by stacking proprietary content and expert judgment on open-source foundations. He explains why owning the model layer beats renting frontier intelligence, and how a rebuilt CoCounsel jumped from 25% to over 70% accuracy.