IBM shares plunged over 13% after AI startup Anthropic announced a tool to modernize COBOL, a key IBM programming language.

IBM ( IBM +2.70%) stock got hit hard in Monday's trading as fears that artificial-intelligence (AI) technologies could disrupt the company's common business-oriented language (COBOL) tech stack. The company's share price fell more than 13% in the daily session, wiping roughly $31 billion off the legacy tech giant's market capitalization.

International Business Machines Corp (NYSE: IBM) shares are rebounding Tuesday morning after plunging more than 13% Monday, when fears about artificial-intelligence disruption hammered the legacy tech giant.

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

IBM stock plunged on Claude Code COBOL fears, but Jefferies says IBM’s watsonx is already modernizing mainframes with GenAI—read more now.

IBM shares slumped on Monday, February 23, 2026, after Anthropic said its AI could speed up COBOL modernization. The stock fell about 13%, marking IBM’s sharpes

IBM or International Business Machines Corp had its worst day on stock market in more than 25 years on Monday, February 23. The 100-year-old IT giant .

Feb 23 (Reuters) - Shares of International Business Machines recorded their steepest daily drop in more than 25 years on Monday, after AI startup Anthropic said its Claude Code tool could be used to modernize a programming language run on IBM systems.