A significant selloff among U.S. and European data analytics, professional services and software companies deepened on Tuesday, with some investors pointing to a recently updated artificial intelligence chatbot by Anthropic as the main culprit.
AI developer Anthropic launched plug-ins for its Claude Cowork agent on Friday that would automate tasks across legal, sales, marketing and data analysis. That move has sparked worries of an impending AI-fueled disruption of the data and professional services industry, which were once seen as major beneficiaries of the AI era, according to traders and analysts.
Toronto-based Thomson Reuters, which owns the Westlaw legal database, slumped by nearly 18%. It is on track for its biggest daily loss on record and lowest close since June 2021.
“I think Anthropic came out with some plug-ins to tackle the legal space,” said Mike Archibald, a portfolio manager at AGF Investments in Toronto. “Obviously, that’s where Thomson Reuters generates a good chunk of their revenues. Sometimes the market just shoots first and asks questions later.”
Thomson Reuters, which is also parent company of Reuters News, is set to report its fourth quarter earnings results on Thursday. Its shares are now down 33% year-to-date after dropping about 22% in 2025.
“Most of the investors we have spoken with recently are overwhelmingly bearish on TRI as the consensus opinion worries that the company will be unable to maintain the same level of growth within its legal segment given increased competition from specialized AI tools,” Morgan Stanley analysts led by Toni Kaplan wrote in an investor note.
Britain’s RELX and the Netherlands’ Wolters Kluwer, both providers of legal analytics services, fell 14% and about 13%, respectively. RELX shares have now almost halved from their peak last February and on Tuesday were set for their biggest drop since 1988. Its dramatic reversal highlights the pressure AI is exerting on Europe’s software sector.
Other professional services firms closed sharply lower too. Factset Research fell 10.5%, Morningstar lost 9% and LegalZoom slumped 19.7%. In London, Experian, Sage Group, London Stock Exchange Group and Pearson fell between 6% and 12%. Traders and analysts said investor fear often outweighed company fundamentals.
“The selling pressure in software and data analytics reflects a deepening structural debate, accelerated today by Anthropic’s legal automation tool challenging incumbents like RELX,” said Schroders analyst Jonathan McMullan. “Investors are aggressively repricing these areas as the historical ‘visibility premium’ erodes; the speed of AI advancement makes long-term valuations harder to defend, particularly as AI tools allow businesses to do more with fewer staff, threatening the traditional model of charging per software user.”
Most large-cap U.S. technology stocks also ended the session lower. Nvidia was down 2.8%, Meta Platforms shed 2.1%, Microsoft dropped 2.9% and Oracle was down 3.4%. The benchmark S&P 500 was down 0.84% while the Nasdaq fell 1.43% to end the session.
Advertising Companies Hit
Advertising companies were also under pressure. New York-based Omnicom was down 11.2% at close, while France’s Publicis shares dived over 9% after the company’s results.
Publicis, the world’s largest advertising group by market capitalisation, said it had earmarked approximately 900 million euros ($1.06 billion) for acquisitions in 2026, focusing on AI-powered technologies and data assets.
Other firms that rely heavily on advertising were also hammered, with Pinterest closing the session down 5.6% and Snap falling 8.4%.
“Artificial intelligence is increasingly able to perform exactly the sort of programming and knowledge-based services that underpin these business models, so parts of the sector have been under pressure for some time,” said Giuseppe Sersale, fund manager at Anthilia.
($1 = 0.8481 euros)
(Reporting by Chibuike Oguh, Fergal Smith, Deborah Sophia, Lucy Raitano, Samuel Indyk, Danilo Masoni and Juby Babu; Editing by Amanda Cooper and Aurora Ellis)
