Core Viewpoint - IBM's stock price plummeted 13.2% to $223.35 per share, marking its worst day since 2000, following an update from Anthropic about its AI tool Claude Code, which threatens IBM's mainframe business [1][2][4] Group 1: Impact of AI on IBM - Anthropic's Claude Code can modernize Cobol, a programming language heavily used in IBM's mainframe systems, automating complex tasks that were previously labor-intensive [1][3] - The update from Anthropic highlights that AI can streamline Cobol modernization, which has historically been cost-prohibitive due to the need for extensive human analysis [3][4] - IBM's reliance on mainframe systems, which are critical for industries like finance and government, poses significant risks as AI tools disrupt traditional business models [5][7] Group 2: Market Reaction and Trends - IBM shares have declined 27% in February, indicating the company's largest one-month drop since at least 1968, driven by fears of AI disruption in the tech sector [2][6] - The broader software market is experiencing a downturn as investors grow wary of tech stocks amid concerns that AI will disrupt established business practices [6][7]