IBM Shares Fall 13% on Anthropic COBOL AI Tool News

International Business Machines Corp. shares plummeted 13 percent on February 23, marking the company's largest single-day decline since October 2000, after artificial intelligence startup Anthropic announced that its Claude Code tool could automate the modernization of COBOL, a legacy programming language central to IBM's mainframe business.

The drop erased billions in market value and contributed to a broader selloff in technology stocks, with IBM's shares falling to around $223, down nearly 29 percent from a high of $313 on February 2. The announcement highlighted Claude Code's ability to map dependencies, trace execution paths, and document workflows in COBOL systems, tasks that traditionally required large teams of consultants working for years. Anthropic stated in a blog post that such automation could compress multiyear projects into quarters, allowing human experts to focus on strategy and risk management. COBOL, developed in the late 1950s, powers an estimated 95 percent of U.S. ATM transactions and hundreds of billions of lines of code in finance, government, and airline operations, much of it running on IBM mainframes.

The news raised investor concerns about...