Stock prices for Thomson Reuters climbed over 11% on Tuesday following news that the company’s artificial intelligence legal assistant, CoCounsel, has reached one million users. The milestone helped ease investor concerns about competitive threats from rival AI technologies in the legal services sector.
Tuesday’s surge marked the company’s largest single-day percentage increase since 2009. The gains came on the same day Anthropic revealed that Thomson Reuters was among several companies utilizing its AI technology for product development.
Earlier this month, a new artificial intelligence tool from Anthropic that incorporates its Claude AI system into legal processes triggered widespread selling across software and services companies. The selloff wiped out $830 billion in market value over six trading sessions as investors worried the technology could reduce industry revenues. Despite Tuesday’s gains, Thomson Reuters stock remains down over 30% for the year due to that earlier decline.
“The legal AI market is maturing, and substance matters more than hype. Our fiduciary-grade AI strategy is driving real adoption — and we have the capital, content, and expertise to shape what comes next,” said Thomson Reuters President and CEO Steve Hasker in an email response regarding the stock movement.
The Toronto-headquartered company that owns Reuters News created CoCounsel following its $650 million acquisition of AI legal startup Casetext in 2023. The AI assistant serves as the primary engine behind CoCounsel Legal, which handles automated research, document analysis, and legal writing tasks for attorneys.
Company executives explained to Reuters following recent quarterly earnings that their legal products stand apart from general AI startups through proprietary intellectual property. This includes centuries of British legal documents and over 100 years of U.S. legal archives, much of which remains undigitized, unpublished, or unavailable to the public.
The Legal Professionals segment represents Thomson Reuters’ largest revenue source, generating approximately one-third of total company sales.
