A Blog Post About Cobol Just Cost IBM $30 Billion. Here's What Actually Happened.
devops.com, Wednesday, February 25th, 2026
On Monday, Anthropic published a blog post about using Claude Code to modernize COBOL. IBM's stock dropped 13% - its worst single-day loss since October 2000. Bloomberg reported the decline put IBM on track for a 27% drop in February, its worst monthly slide since at least 1968.
Accenture and Cognizant also fell. The selling continued a pattern from Friday, when Anthropic's Claude Code Security announcement sent cybersecurity stocks tumbling. In less than a week, Anthropic blog posts have triggered two separate market selloffs across entirely different sectors.
But here's the thing. What Anthropic actually announced is a playbook for using AI to help analyze and refactor COBOL code. That's a real capability. It's also something IBM, OpenAI, AWS, Microsoft, and every major systems integrator has been saying - and shipping - for years.