What They Did
Thomson Reuters is a global information services giant, best known for Westlaw — the dominant legal research database used by nearly every law firm in the English-speaking world. Their moat was decades of curated legal data, case law, and proprietary analysis that lawyers depended on daily.
How LLMs Killed Them
On February 3, 2026, Anthropic released Claude Cowork with legal plugins that could automate contract review, risk flagging, NDA triage, and compliance tracking — core revenue functions for Thomson Reuters and its competitors. This triggered what traders dubbed the "Claude Crash," the largest single-day stock drops in these companies' histories. The market realized that LLMs could process and reason over legal text at a fraction of the cost of subscription databases.
Timeline
- February 3, 2026: Anthropic launched Claude Cowork with legal workflow plugins.
- February 3-4, 2026: Thomson Reuters stock crashed 17.5% — the worst single-day drop in company history. RELX (LexisNexis parent) fell 14%. Wolters Kluwer fell 13%.
- February 2026: Combined ~$100B+ in market cap wiped from legal information companies in 48 hours.
- February 2026: Analysts debated whether the selloff was irrational panic or correct repricing of a genuinely disrupted industry.
By the Numbers
- Stock down 17.5% in one day — worst ever
- RELX (LexisNexis) down 14% the same day
- Wolters Kluwer down 13% the same day
- Combined ~$100B+ in market cap wiped in 48 hours
- Goldman Sachs compared trajectory to newspaper industry's 95% stock decline from 2002-2009