Is Arthur J. Gallagher & Co. overvalued or undervalued?

As of 7 July 2025, the valuation grade for Arthur J. Gallagher & Co. moved from fair to expensive, indicating that the company is overvalued. Key valuation ratios highlight this assessment, with a P/E ratio of 52, a Price to Book Value of 3.77, and an EV to EBITDA of 20.04, all of which are significantly higher than its peers. For comparison, Marsh & McLennan Cos., Inc. has a P/E of 24.92 and Aon Plc has a P/E of 29.25, underscoring Gallagher's relative overvaluation.
Furthermore, while the company has shown strong long-term performance with a 5-year return of 184.75%, this is overshadowed by the S&P 500's 10-year return of 231.64%, suggesting that Gallagher has underperformed relative to the broader market over the long term. Overall, these factors contribute to the conclusion that Arthur J. Gallagher & Co. is currently overvalued.