Cyber Stocks Plummet as Anthropic Unveils Autonomous AI Security

Cybersecurity stocks, including Rapid7, Tenable, SentinelOne, Zscaler, and Qualys, fell sharply on February 20, 2026, after Anthropic launched Claude Code Security. Investors fear the AI tool, which autonomously scans codebases and suggests patches, could replace high-margin legacy security software. Qualys (QLYS) extended recent losses, trading at $92.18, down 40.1% from its November 2025 high. The stock has declined 29.6% year-to-date, compounding a 13.4% drop on February 6, 2026, following weak guidance. Management projected adjusted EPS of $7.31 and first-quarter sales growth of 8.5%, missing estimates and signaling a deceleration from the prior quarter's 10.1% growth.