IBM Shares Plunge 13% in Biggest Drop Since 2000 as Anthropic AI Threatens $2.5B COBOL Business

Big Blue just got hit hard. IBM stock crashed 13.2% on Monday, February 23rd, 2026 — its worst single-day plunge since October 2000. The selloff was triggered by Anthropic announcing that its Claude Code AI tool can now automate COBOL modernization work, directly attacking IBMs lucrative legacy systems business. For those who dont know, COBOL is this ancient programming language still running on IBM mainframes across banks, insurance companies, and government agencies worldwide. IBM makes an estimated $2.5 billion annually from COBOL-related services — maintenance, upgrades, the whole nine yards. Its been their cash cow for decades. But Anthropic dropped a bombshell: their AI can now handle the complex exploration and analysis work required to refactor COBOL code. Translation: enterprises might no longer need IBMs expensive consultants to modernize their systems. Why pay hundreds of dollars per hour when AI can do it faster? The timing is brutal too. IBM shares have now fallen 27% in February alone — on track for their worst monthly decline since at least 1968. Investors are clearly worried that the AI revolution is coming for IBMs enterprise revenue stream. Some IBM miners running AI infrastructure actually benefited from the chaos. IREN jumped 5%, Cipher Mining rose 3.4%, CleanSpark added 1.5%, and Hut 8 gained 0.7%. The market is clearly rotating away from traditional tech giants toward AI infrastructure plays. CZ, the former Binance chief, had a field day commenting on the situation. He pointed out that traditional finance types have spent years warning about crypto volatility, but maybe they should be more worried about AI eating their lunch instead. Ouch. The broader tech market felt the ripple effects. Crypto markets tanked alongside the stock selloff, with Bitcoin dropping back to around $64,000 as investors fled risk assets. The correlation between AI developments and crypto moves is becoming increasingly obvious. What does this mean for the enterprise software space? If AI can handle COBOL modernization, what other legacy technologies are next? mainframe systems, anyone? The writing is on the wall — enterprises are going to accelerate their AI adoption plans, and traditional vendors like IBM need to adapt or risk becoming irrelevant.