# software shares tumbled on Thursday after Anthropic held back the wide release of a powerful AI model.

*business · news · 2026-04-09 · The Star*

## Key points

- Anthropic restricted access to its Claude Mythos AI model due to cybersecurity vulnerability concerns.
- Claude Mythos has already uncovered thousands of vulnerabilities in every major OS and web browser.
- Only about 40 companies, including Microsoft and Google, have access to Claude Mythos.
- The S&P 500 Software and Services Index has dropped nearly 26% this year amid AI disruption fears.
- BTIG downgraded Zscaler to 'neutral' from 'buy' due to demand and competition concerns.

**Companies:** Microsoft, Google, Adobe, Salesforce, Cloudflare, Okta, CrowdStrike, SentinelOne, Atlassian, Workday, Intuit, Zscaler
**Countries:** United States

[Read the full story on The Star](https://www.thestar.com.my/tech/tech-news/2026/04/09/us-software-stocks-fall-as-anthropic039s-new-ai-model-revives-disruption-fears)

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