Shares of leading cybersecurity pure-play Fortinet (FTNT 0.87%) closed out 2023 on a sour note. Management downgraded its prior financial guidance, and left the door open for a significant slowdown in business growth in 2024. Investors were mighty displeased, although it's worth noting that Fortinet stock still managed to rise 20% in 2023 thanks to a year-end rally. Nevertheless, the cybersecurity market is still riding massive demand as cloud computing growth continues unabated. Is it time to buy Fortinet ...