How an Anthropic AI release triggered a $285 billion stock sell-off

A sharp sell-off across global technology and software stocks last week was triggered by a new AI release from Anthropic, wiping out $285 billion in market value in a single trading session. The drop followed the company’s decision to release a set of AI plugins aimed at automating professional workflows, including legal work. Also Read: Grok Imagine 1.0 brings 10-second AI videos with audio support to take on OpenAI’s Sora

What Anthropic released

Anthropic recently expanded its AI assistant Claude with a new set of open-source plugins under a tool called Claude Cowork. The plugins are meant to help businesses handle everyday tasks across areas like marketing, finance, sales, data analysis, and customer support. Also Read: From Moltbot to Moltbook: The AI experiment making the internet uncomfortable

One plugin, focused on legal workflows, drew the most attention. According to Anthropic, it can assist with contract reviews, NDA checks, compliance summaries, and basic legal drafting. The company clarified that the tool does not provide legal advice and that all outputs should be reviewed by qualified professionals. Also Read: ChatGPT is losing GPT-4o and other models as OpenAI shifts focus to GPT-5 models

Despite that clarification, the market reaction was swift.

Why the market reacted so strongly

Investors appeared concerned that Anthropic is no longer just offering an AI model but is now moving directly into workflow automation. Until now, many software and legal-tech firms used AI models as building blocks for their own products. With ready-made tools now available directly from the model provider, that relationship starts to look different.

Analysts cited by outlets such as The Wall Street Journal and Jefferies noted that the fear was not about a single legal tool, but about what it signals. The concern is that if AI companies start controlling entire workflows, many existing software platforms could lose their importance sooner than expected.

Stocks that took a hit

The impact was immediate across multiple markets. In the US, shares of Thomson Reuters, LegalZoom, and other legal and financial data firms fell sharply. A Goldman Sachs basket tracking software stocks recorded its worst single-day fall in months.

The sell-off also spread beyond the US. European firms such as RELX and Wolters Kluwer dropped by double digits. Indian IT stocks were pulled down as well, with Infosys, Wipro, TCS, and HCLTech falling as overseas sentiment weakened, according to market reports.

Two major US indices tracking software and financial data companies together lost close to $300 billion in value during the session.

The bigger picture

Market experts told publications like The Wall Street Journal that investors are becoming more cautious as AI development accelerates. The concern is not whether AI will help software companies, but whether it will replace parts of what they do.

Add Techlusive as a Preferred Source

Anthropic’s move shows how quickly the conversation has shifted. A set of publicly released tools, rather than a new model launch, was enough to shake confidence across the sector and trigger one of the largest single-day sell-offs seen in recent months.