Ibm Stock rout: ibm stock plunges 13.5% after Anthropic COBOL warning

ibm stock tumbled 13. 5% on Monday after Anthropic renewed fears that AI code assistants could disrupt legacy COBOL workloads, a move that erased roughly $31 billion in market value. Shares were up only slightly on Tuesday as analysts and IBM responded to the shock.

Anthropic blog: hundreds of billions of COBOL lines remain in production across finance, airlines and government

Anthropic (ANTH. PVT) said in a new blog post that hundreds of billions of lines of COBOL remain in daily production across finance, airlines, and government. The company argued that AI can now automate analysis tasks that historically made modernization slow and costly.

The post highlighted COBOL's continuing role in mission-critical infrastructure — payments and financial systems among them — where IBM has been the leader for years.

Ibm Stock market shock wiped $31 billion as "the AI scare trade is taking no prisoners"

The market reaction was swift: IBM (IBM) stock sold off to the tune of 13. 5% on Monday, a move the coverage framed as part of a broader AI scare trade that "is taking no prisoners. " That sell-off caused $31 billion in market value to go up in smoke. By Tuesday, shares were up only slightly.

IBM response: watsonx Code Assistant for Z and long-term engineering challenges

: "IBM has been investing in code modernization for years — both through skilling initiatives and through our own generative AI capabilities. More than two years ago, we launched watsonx Code Assistant for Z (IBM's mainframe) because we understand the benefit of AI in modernizing code. New AI tools emerge every week, including our own. What they do not change is the fundamental engineering challenge of running mission-critical workloads at scale. Translating COBOL is the easy part. The real work is data architecture redesign, runtime replacement, transaction processing integrity, and hardware-accelerated performance built over decades of tight software and hardware coupling. That is the problem IBM has spent decades learning to solve, and AI is the most powerful tool we have ever had to do it. "

Evercore's Amit Daryanani lists six advantages for mainframe customers and keeps Outperform with a $345 target

Evercore analyst Amit Daryanani pushed back on the rout, saying clients have long had the option to migrate from the mainframe but are sticking with the platform because of several advantages. He listed: 1) Reliability: 100% uptime and the ability to hot swap components (even the best run clouds might only have 5-6 nines of uptime), 2) speed, volume, & throughput, 3) better cost efficiency at scale, 4) On-prem AI inferencing capabilities for real-time analytics, 5) Security: Quantum-safe encryption, and 6) Regulatory Considerations: Mainframes are widely used by sensitive industry verticals such as governments, healthcare, & financial services (migrating to public cloud not an option). Daryanani wrote that he thinks customers choose to remain on mainframe given these advantages despite the availability of alternatives for several decades. He said he believes today's sell-off is unwarranted and would be buyers on weakness... Maintain Outperform rating and $345 target.

Analyst note: IBM's broader software story, mainframe revenue share and growth drivers

Another analyst wrote: "At its core, IBM remains a software-driven story with multiple secular growth vectors across hybrid cloud, AI, automation and data. While mainframe software is an important contributor given its high margins and durability (mainframe accounts for ~23%/29% of IBM's 2025 total revenue/software revenue), it is not the linchpin of IBM's broader software re-acceleration narrative. The push toward sustained 10%+ software growth is being driven by portfolio expansion in areas like Red Hat, watsonx, automation, and data platforms that extend well beyond Z. We view the sell-off as a near-term sentiment overhang on legacy services rather than an existential or structural" — the remainder of that comment is unclear in the provided context.