Anthropic Has Nuked $300B+ in Market Cap Across 5 Sectors

Five releases. Five sectors. One company repeatedly obliterating market cap at scale.

From Claude Cowork plugins (Feb 3) wiping $285B off legal, finance, and marketing stocks in a single session — Thomson Reuters −15.8%, LegalZoom −19.7%, WPP −12% — to the Claude COBOL announcement (Feb 23) that sent IBM down 13.2%, its worst day in 25 years, erasing $31B. In between: Claude Code Security (Feb 20) knocked CrowdStrike and Cloudflare 8–10% each. Then came the accidental leak of Claude Mythos (Mar 27), an unreleased model Anthropic privately warned government officials could enable large-scale cyberattacks — triggering another wave: CrowdStrike −7%, Palo Alto −6%, Zscaler −4.5%.

Each drop followed the same logic: if Claude can do it cheaply and autonomously, the premium pricing of incumbents collapses. Markets are repricing entire categories of enterprise software in real time.

Why it matters: Anthropic isn't just building AI — it's serially repricing the value of human expertise across industries, and the market is keeping score.