IBM Faces Fallout After Anthropic Touts AI's Cobol Prowess

Anthropic's blog post about its AI's ability to modernize legacy Cobol code sends IBM stock plunging.

Feb. 24, 2026 at 10:56am by Ben Kaplan

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IBM's stock took a significant hit after Anthropic, an AI company, published a blog post boasting about its AI system Claude's ability to modernize outdated Cobol computer code. Cobol, a programming language dating back to 1959, is still widely used in critical applications like ATM transactions, but finding programmers fluent in the language is becoming increasingly difficult. Anthropic claims its AI can modernize Cobol codebases in a fraction of the time it would take human programmers, causing panic on Wall Street about the potential impact on IBM's Cobol-related services and tools.

Why it matters

The fallout from Anthropic's blog post highlights the growing influence of AI companies and the anxiety around the potential disruption of traditional tech giants like IBM. As AI systems demonstrate their ability to tackle complex legacy technology challenges, it raises questions about the future of certain IT services and the need for companies to adapt quickly to the changing landscape.

The details

Cobol, a programming language created in 1959, is still widely used in critical applications, with an estimated 95% of ATM transactions in the U.S. relying on Cobol-based systems. However, the pool of programmers fluent in Cobol is dwindling, making it difficult for companies to maintain and modernize their Cobol-based applications. Anthropic's blog post claimed that its AI system, Claude, can modernize Cobol codebases in a matter of quarters, rather than the years it would typically take human programmers. This assertion sent IBM's stock plunging more than 13%, the biggest single-day drop for the company since October 2000, as Wall Street reacted to the potential threat to IBM's Cobol-related services and tools.

  • On Monday, Anthropic published a blog post about its AI's Cobol modernization capabilities.
  • IBM's stock dropped more than 13% on the same day, the biggest single-day decline since October 2000.

The players

Anthropic

An AI company that published a blog post touting its AI system's ability to modernize legacy Cobol code.

IBM

A technology giant that has long offered services and tools, including AI-based tools, to help customers modernize their Cobol applications.

Claude

Anthropic's AI system that the company claims can modernize Cobol codebases in a fraction of the time it would take human programmers.

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What’s next

The fallout from Anthropic's blog post is likely to continue, as investors and industry observers closely monitor the impact on IBM's Cobol-related business and the broader implications for traditional tech giants facing AI-driven disruption.

The takeaway

This incident highlights the growing influence of AI companies and the anxiety around the potential disruption of legacy technology. As AI systems demonstrate their ability to tackle complex challenges, it raises questions about the future of certain IT services and the need for companies to adapt quickly to the changing landscape.