Anthropic’s new AI tool triggered a stock plunge in legal data firms like Westlaw and LexisNexis.

Stocks in data and information services plunged after Anthropic launched a new AI tool, CoWork Legal, which automates legal tasks like contract review and compliance tracking. The tool, powered by Anthropic’s in-house Claude 3.5 Sonnet model, directly challenges established legal platforms like Westlaw and LexisNexis, triggering sharp declines in companies including RELX, Thomson Reuters, Wolters Kluwer, and Experian, with some losing over 10%. The sell-off reflected growing investor concerns over AI disrupting traditional data-driven business models, especially as Anthropic’s customizable, enterprise-ready AI gives it an edge over competitors relying on third-party models. Broader market anxiety was fueled by weak software sector earnings and fears of widespread job losses in professional services, with the UK seeing more AI-driven job losses than gains.