IBM stock crash: How a single blog post wiped $30 billion off IBM’s market value in one afternoon - here's what rattled investors

IBM stock crash shocked Wall Street. IBM shares fell 13% in one day. Nearly $30 billion in market value vanished. This was IBM’s worst drop since 2000. The trigger was not earnings. It was an AI blog post by Anthropic. The post introduced a COBOL modernization AI tool. Investors fear AI disruption in legacy systems. IBM mainframe revenue now faces pressure. Markets repriced risk instantly.