Is Fortinet, Inc. overvalued or undervalued?

As of 17 October 2025, the valuation grade for Fortinet, Inc. has moved from expensive to very attractive, indicating a significant improvement in its valuation outlook. Based on the metrics provided, Fortinet appears to be undervalued, particularly when considering its P/E ratio of 43, which is notably higher than the peer average of 32.08 for similar companies like Cisco Systems, Inc. and Accenture Plc, which have P/E ratios of 23.85 and 21.26, respectively. Additionally, Fortinet's PEG ratio of 0.79 suggests that the stock is priced favorably relative to its growth prospects.
In terms of performance, Fortinet has shown a mixed return profile compared to the S&P 500, with a year-to-date return of -11.69% compared to the index's 13.30%, but it has outperformed over the longer term with a 5-year return of 217.17% versus the S&P 500's 91.29%. This divergence in returns reinforces the narrative that while Fortinet may currently be undervalued, its long-term growth potential remains strong.