Is MasTec, Inc. overvalued or undervalued?

As of 31 October 2025, the valuation grade for MasTec, Inc. has moved from fair to expensive, indicating that the stock is overvalued. The company exhibits a P/E ratio of 60, a Price to Book Value of 5.55, and an EV to EBITDA of 18.89, all of which suggest that the stock is priced significantly above its fundamental value. In comparison, EMCOR Group, Inc. has a P/E of 29.12 and Comfort Systems USA, Inc. has a P/E of 38.72, both of which are more reasonable relative to MasTec's valuation.
Despite the overvaluation, MasTec has shown strong performance, with a year-to-date return of 49.96% compared to the S&P 500's 16.30%, and a remarkable 5-year return of 311.28% against the S&P 500's 109.18%. This performance, however, does not mitigate the fact that the current valuation metrics indicate that MasTec, Inc. is overvalued.