The HAL 9000 nightmare is manifesting as agentic ransomware and AI models capable of sophisticated hacking. For cybersecurity firms like Fortinet, however, that’s an ideal growth market. Shares in the Sunnyvale, Calif.-based company rose an eye-popping 20% Thursday, a day after executives reported an earnings beat after the bell. Analysts say investors can expect a lot more value where that came from. Securing Growth Fortinet makes custom chip…