Is Comfort Systems USA, Inc. overvalued or undervalued?

As of 1 August 2025, the valuation grade for Comfort Systems USA, Inc. moved from attractive to fair. The company appears to be fairly valued based on its current metrics. Key ratios include a P/E ratio of 31, an EV to EBITDA of 21.24, and a PEG ratio of 0.45, which suggests that while the stock is priced higher than some peers, it may still offer growth potential relative to its earnings.
In comparison to peers, EMCOR Group, Inc. has a more attractive P/E of 29.12 and an EV to EBITDA of 19.49, while AECOM is considered very expensive with a P/E of 22.09. Notably, Comfort Systems has significantly outperformed the S&P 500, with a YTD return of 88.51% compared to the index's 12.22%, indicating strong market performance despite its current valuation status.