Is ONE Gas, Inc. overvalued or undervalued?

As of 17 October 2025, the valuation grade for ONE Gas, Inc. moved from fair to expensive, indicating a shift in perception regarding its market value. The company appears overvalued based on its current metrics, including a P/E ratio of 18, an EV to EBITDA ratio of 10.31, and a Price to Book Value of 1.38. Compared to peers, ONE Gas, Inc. has a higher P/E ratio than New Jersey Resources Corp., which stands at 11.53 and is considered attractive, while Spire Inc. has a fair valuation with a P/E of 15.53.
In terms of recent performance, ONE Gas, Inc. has outperformed the S&P 500 over the past year with a return of 10.20% compared to the index's 14.08%. However, over longer periods, such as the 3-year and 5-year returns, the company has significantly lagged behind the S&P 500, which returned 81.19% and 91.29%, respectively. This suggests that while the stock has shown some short-term strength, its long-term valuation may not be justified given its current ratios.