breaking February 24, 2026

Anthropic Says Claude Can Replace the Backbone of Global Banking. IBM Lost $30 Billion in a Day.

Anthropic’s Claude Code just targeted COBOL - the 60-year-old programming language powering 95% of U.S. ATM transactions and hundreds of billions of lines of critical infrastructure. IBM shares collapsed 13.2% on news the AI can automate what once took human analysts months.

Anthropic fired a shot at the foundations of enterprise computing on Monday - and the market’s response was immediate and brutal.

IBM shares collapsed 13.2% by close, their steepest single-day decline since October 2000, wiping roughly $30 billion from the company’s market capitalization. The trigger: a blog post from Anthropic announcing that Claude Code can now automate the analysis, mapping, and modernization of COBOL - the programming language that has quietly run the world’s financial infrastructure for six decades.

What COBOL Actually Is

COBOL is not an obscure relic. Common Business-Oriented Language, developed in the late 1950s, runs hundreds of billions of lines of production code every single day. It processes an estimated 95% of ATM transactions in the United States. It runs the back-end systems of major banks, insurance companies, airline reservation platforms, and government agencies.

The problem is that the generation of developers who understood COBOL is retiring. The number of people who can read and maintain it “shrinks every year,” Anthropic noted in its Monday blog post. What remains is a mountain of critical, largely undocumented code that businesses desperately want to modernize - but can’t afford to, because understanding legacy code historically costs more than rewriting it.

Anthropic says Claude flips that equation.

What Claude Code Can Now Do

The capability Anthropic announced isn’t translation - it’s comprehension at scale. Claude Code can map dependencies across thousands of lines of COBOL, surface undocumented workflows, identify downstream risks, and generate documentation for processes “that would take human analysts months to surface.”

“Legacy code modernization stalled for years because understanding legacy code cost more than rewriting it,” Anthropic wrote. “AI flips that equation.”

The announcement builds on a broader offensive Anthropic has been running against legacy enterprise software. Just last Friday, the company unveiled Claude Code Security - a codebase scanning capability designed to find software vulnerabilities - which sent cybersecurity stocks tumbling. The sector remained under pressure Monday as the IBM announcement compounded investor anxiety about AI’s reach into established enterprise categories.

Who Gets Hit

IBM isn’t the only casualty. Shares of Accenture and Cognizant - both major players in enterprise modernization and COBOL migration services - also declined on the news. These companies have built significant consulting and managed services businesses around the complexity of legacy system transitions. If Claude Code can compress months of analyst work into hours, the economic case for those engagements erodes.

The industries most exposed are finance, insurance, airlines, and government - the same industries that have been slowest to modernize precisely because their COBOL systems are the most mission-critical and the most difficult to safely replace.

The Structural Shift

What the market is pricing in is not a new product feature. It is a fundamental change in the cost structure of enterprise modernization.

For decades, the friction in modernizing COBOL systems was not technical willingness but economic reality: the discovery and documentation phase alone was prohibitively expensive. Organizations would commission studies, hire specialized consultants, spend months mapping what their own code actually did - and often abandon the effort before a single line was rewritten.

Anthropic is claiming that Claude Code removes that bottleneck entirely. If true, it doesn’t just threaten IBM’s mainframe consultancy revenues. It threatens the entire professional services ecosystem that has been maintained by the inaccessibility of legacy code.

What IBM Says

IBM has not issued a direct response to Anthropic’s announcement. The company’s silence, in the context of a 13% stock collapse, speaks clearly enough.

See also: Anthropic: $19B Run Rate Rewrites AI Revenue.

For related context, see Anthropic.

“Legacy code modernization stalled for years because understanding legacy code cost more than rewriting it,” Anthropic wrote. “AI flips that equation.”

The announcement builds on a broader offensive Anthropic has been running against legacy enterprise software. Just last Friday, the company unveiled Claude Code Security - a codebase scanning capability designed to find software vulnerabilities - which sent cybersecurity stocks tumbling. The sector remained under pressure Monday as the IBM announcement compounded investor anxiety about AI’s reach into established enterprise categories.

Who Gets Hit

IBM isn’t the only casualty. Shares of Accenture and Cognizant - both major players in enterprise modernization and COBOL migration services - also declined on the news. These companies have built significant consulting and managed services businesses around the complexity of legacy system transitions. If Claude Code can compress months of analyst work into hours, the economic case for those engagements erodes.

The industries most exposed are finance, insurance, airlines, and government - the same industries that have been slowest to modernize precisely because their COBOL systems are the most mission-critical and the most difficult to safely replace.

The Structural Shift

What the market is pricing in is not a new product feature. It is a fundamental change in the cost structure of enterprise modernization.

For decades, the friction in modernizing COBOL systems was not technical willingness but economic reality: the discovery and documentation phase alone was prohibitively expensive. Organizations would commission studies, hire specialized consultants, spend months mapping what their own code actually did - and often abandon the effort before a single line was rewritten.

Anthropic is claiming that Claude Code removes that bottleneck entirely. If true, it doesn’t just threaten IBM’s mainframe consultancy revenues. It threatens the entire professional services ecosystem that has been maintained by the inaccessibility of legacy code.

What IBM Says

IBM has not issued a direct response to Anthropic’s announcement. The company’s silence, in the context of a 13% stock collapse, speaks clearly enough.

Monday’s sell-off brings IBM shares down more than 24% year to date - a staggering reversal for a company that spent years repositioning itself as an AI-forward enterprise platform. The irony is direct: IBM embraced AI as a competitive moat, and AI is now being used to dismantle the legacy infrastructure that gave IBM its most durable advantage.

Anthropic did not announce pricing for Claude Code’s COBOL modernization capabilities. That detail, when it arrives, will determine how quickly the disruption accelerates.