IBM is the latest AI casualty. Shares are tanking 11% on Anthropic programming language threat

International Business Machines stock is getting slammed, becoming the latest victim of rapidly developing AI technology, after Anthropic's Claude announced COBOL capabilities.

Shares of IBM fell 11% in Monday afternoon trading after Anthropic outlined a new use case for its Claude Code product: automating the exploration and analysis work that drives most of the complexity in COBOL modernization.

COBOL is a programming language used widely in business data processing, which is a core business area for IBM. COBOL, short for Common Business-Oriented Language, was developed in the 1950s and continues to powers systems responsible for large volumes of transactions, including payment processing and retail transaction systems.

In a Monday blog post, Anthropic wrote that COBOL handles an estimated 95% of ATM transactions in the U.S. "Hundreds of billions of lines of COBOL run in production every day, powering critical systems in finance, airlines, and government. Despite that, the number of people who understand it shrinks every year," the Anthropic blog post reads.

"Legacy code modernization stalled for years because understanding legacy code cost more than rewriting it. AI flips that equation," the post continued. It then explained that Claude Code can help modernize COBOL codebases by mapping dependencies across thousands of lines of code, documenting workflows and identifying risks that "would take human analysts months to surface."

Monday's move brought IBM shares down nearly 22% year to date.

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