IBM stock falls after Anthropic says AI can now modernize old software

IBM still profits from mainframes running decades-old COBOL systems. Anthropic says AI can migrate that software elsewhere.

IBM stock was down 10% on Monday afternoon after Anthropic published a blog post about how its Claude Code tool can be used to modernize software written in the COBOL language, which handles large-scale batch transactions. Many of the software systems used by the federal government, banks, and airlines are written in COBOL (“Common Business-Oriented Language”), and most of those systems run on IBM mainframes.