Is Comfort Systems USA, Inc. overvalued or undervalued?

As of 17 October 2025, the valuation grade for Comfort Systems USA, Inc. has moved from very expensive to expensive. The company is currently considered overvalued based on its high valuation ratios compared to peers. The P/E ratio stands at 31, while the PEG ratio is notably low at 0.45, indicating potential growth relative to its price. Additionally, the EV to EBITDA ratio is 21.24, which is higher than that of its peer EMCOR Group, Inc., which has a P/E of 29.12 and an EV to EBITDA of 19.49.
In comparison to the S&P 500, Comfort Systems has shown impressive returns, with a year-to-date return of 95.24% compared to the S&P 500's 13.30%, and a staggering 691.81% return over three years versus the S&P 500's 81.19%. This strong performance may suggest that the market has high expectations for the company's future growth, despite its current overvaluation.