IBM Stock Plummets as Anthropic’s AI Threatens COBOL Modernization Business

Shares of International Business Machines (IBM) experienced a significant downturn on Monday, February 23, 2026, falling 13.2% to close at $223.35 per share. This decline followed an announcement by Anthropic regarding its Claude Code tool and its potential to automate the modernization of COBOL systems, a key area of IBM’s business.

The COBOL Challenge and IBM’s Role

COBOL (Common Business-Oriented Language), developed in the late 1950s, remains a dominant force in business data processing, powering critical systems in finance, airlines, and government. An estimated 95% of ATM transactions in the U.S. Rely on COBOL, according to Anthropic . IBM has long been a major provider of mainframe systems optimized for large-scale transaction processing where COBOL is frequently used, and also generates revenue from servicing, modernizing, and consulting on these mainframes.

Why COBOL Modernization is Difficult

Modernizing COBOL systems is a complex and costly undertaking. The code, often decades old, can be difficult to understand due to poor documentation and reflects years of institutional knowledge. The number of programmers proficient in COBOL is dwindling, as most university computer science programs no longer teach the language. The most challenging aspect of modernization has traditionally been the analysis phase – understanding the existing code and its intricacies.

Anthropic’s Claude Code: An AI Solution

Anthropic asserts that its Claude Code tool can significantly reduce the time and cost associated with COBOL modernization. The tool automates the exploration and analysis of COBOL codebases, mapping dependencies, documenting workflows, and identifying potential risks. According to Anthropic, Claude Code can accomplish in quarters what previously took years . The company highlights that AI excels at streamlining tasks that once made COBOL modernization prohibitively expensive.

IBM’s Perspective

IBM acknowledges the potential of AI in modernization efforts but emphasizes that the analysis phase is not the sole challenge. According to an IBM spokesperson, translating COBOL is relatively straightforward; the more significant hurdles lie in data architecture redesign, runtime replacement, transaction processing integrity, and maintaining the hardware-accelerated performance built over decades of tight software and hardware coupling . IBM believes it has decades of experience solving these broader problems and views AI as a powerful tool to aid in this process.

Market Impact and Future Outlook

The announcement triggered a substantial sell-off of IBM stock, representing its worst single-day performance since 2000. IBM shares have fallen 27% in February, putting them on track for their largest one-month decline since at least 1968 . The situation highlights the growing impact of AI on established technology companies and the potential for disruption in legacy systems.