# Cybersecurity stocks were the top performers in the S&P 500 on Monday amid escalating AI fears; CrowdStrike rose 14%, Palo Alto Networks 13%, and Fortinet 9% (Britney Nguyen/MarketWatch)

> Cybersecurity stocks were the best performers in the S&P 500 on Monday, rallying even as broader nervousness about AI rattled the market. CrowdStrike rose about 14 percent, Palo Alto Networks about 13 percent, and Fortinet about 9 percent, a sharp move for a single session. The rally reflects a bet investors are increasingly comfortable making: whatever happens with AI, the security business benefits. As AI tools make attacks cheaper and more automated, demand for defense rises in step, so the same fears weighing on other names can read as a tailwind for the companies that sell protection. It is a reminder that market reactions to AI are not uniform. Alongside worries about a slowdown and overheated valuations, money is rotating toward parts of the stack seen as durable no matter how the frontier debate resolves. Whether the enthusiasm holds is another question, but for one day at least, the clearest way to express an AI view on Wall Street was to buy the companies guarding against its misuse.

_Section: [Daily AI Updates](https://www.wortins.com/daily-ai) · Source: MarketWatch · Published Tuesday, September 15, 2026_

## Wortins' read

Cybersecurity stocks were the best performers in the S&P 500 on Monday, rallying even as broader nervousness about AI rattled the market. CrowdStrike rose about 14 percent, Palo Alto Networks about 13 percent, and Fortinet about 9 percent, a sharp move for a single session. The rally reflects a bet investors are increasingly comfortable making: whatever happens with AI, the security business benefits. As AI tools make attacks cheaper and more automated, demand for defense rises in step, so the same fears weighing on other names can read as a tailwind for the companies that sell protection. It is a reminder that market reactions to AI are not uniform. Alongside worries about a slowdown and overheated valuations, money is rotating toward parts of the stack seen as durable no matter how the frontier debate resolves. Whether the enthusiasm holds is another question, but for one day at least, the clearest way to express an AI view on Wall Street was to buy the companies guarding against its misuse.

## Source

[Read the full story at MarketWatch](https://www.techmeme.com/260914/p42#a260914p42)

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