OGS vs. FXAIX

Last updated Apr 1, 2026

Compare and contrast key facts about ONE Gas, Inc. (OGS) and Fidelity 500 Index Fund (FXAIX).

FXAIX is a passively managed fund by Fidelity that tracks the performance of the S&P 500 Index. It was launched on Feb 17, 1988.

Performance

OGS vs. FXAIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in ONE Gas, Inc. (OGS) and Fidelity 500 Index Fund (FXAIX). The values are adjusted to include any dividend payments, if applicable.

OGS vs. FXAIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
OGS ONE Gas, Inc.	12.39%	15.57%	13.08%	-12.77%	0.63%	4.36%	-15.74%	20.26%	11.40%	17.30%
FXAIX Fidelity 500 Index Fund	-7.05%	17.84%	25.01%	26.29%	-18.14%	28.71%	18.42%	31.48%	-4.43%	21.82%

Returns By Period

In the year-to-date period, OGS achieves a 12.39% return, which is significantly higher than FXAIX's -7.05% return. Over the past 10 years, OGS has underperformed FXAIX with an annualized return of 6.60%, while FXAIX has yielded a comparatively higher 13.75% annualized return.

OGS

• 1D: -0.05%
• 1M: -1.50%
• YTD: 12.39%
• 6M: 8.15%
• 1Y: 17.89%
• 3Y*: 6.69%
• 5Y*: 5.94%
• 10Y*: 6.60%

FXAIX

• 1D: -0.39%
• 1M: -7.68%
• YTD: -7.05%
• 6M: -4.59%
• 1Y: 14.42%
• 3Y*: 17.17%
• 5Y*: 11.40%
• 10Y*: 13.75%

*Multi-year figures are annualized to reflect compound growth (CAGR)

Return for Risk

OGS vs. FXAIX — Risk / Return Rank

Compare risk-adjusted metric ranks to identify better-performing investments over the past 12 months.

OGS

OGS Risk / Return Rank: 69
OGS Sharpe Ratio Rank: 75
OGS Sortino Ratio Rank: 66
OGS Omega Ratio Rank: 64
OGS Calmar Ratio Rank: 71
OGS Martin Ratio Rank: 68

FXAIX

FXAIX Risk / Return Rank: 46
FXAIX Sharpe Ratio Rank: 41
FXAIX Sortino Ratio Rank: 45
FXAIX Omega Ratio Rank: 50
FXAIX Calmar Ratio Rank: 41
FXAIX Martin Ratio Rank: 53

The rank (0–100) shows how this investment's returns compare to the risk taken. Higher = better. Based on the past 12 months of data, combining Sharpe, Sortino, and other metrics used by quantitative funds and institutional investors.

OGS vs. FXAIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for ONE Gas, Inc. (OGS) and Fidelity 500 Index Fund (FXAIX). Risk-adjusted metrics are performance indicators that assess an investment's returns in relation to its risk, enabling a more accurate comparison of different investment options.

	OGS	FXAIX	Difference
Sharpe ratio Return per unit of total volatility	0.99	0.84	+0.16
Sortino ratio Return per unit of downside risk	1.41	1.30	+0.11
Omega ratio Gain probability vs. loss probability	1.18	1.20	-0.02
Calmar ratio Return relative to maximum drawdown	1.47	1.05	+0.42
Martin ratio Return relative to average drawdown	2.98	5.13	-2.15
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

OGS vs. FXAIX - Sharpe Ratio Comparison

The current OGS Sharpe Ratio is 0.99, which is comparable to the FXAIX Sharpe Ratio of 0.84. The chart below compares the historical Sharpe Ratios of OGS and FXAIX, offering insights into how both investments have performed under varying market conditions. These values are calculated using daily returns over the previous 12 months.

Sharpe Ratios by Period

	OGS	FXAIX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	0.99	0.84	+0.16
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.25	0.68	-0.42
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.26	0.77	-0.51
Sharpe Ratio (All Time) Calculated using the full available price history	0.46	0.75	-0.30

Correlation

The correlation between OGS and FXAIX is 0.31, which is considered to be low. This implies their price changes are not closely related. A low correlation is generally favorable for portfolio diversification, as it helps to reduce overall risk by spreading it across multiple assets with different performance patterns.

Dividends

OGS vs. FXAIX - Dividend Comparison

OGS's dividend yield for the trailing twelve months is around 3.12%, more than FXAIX's 1.20% yield.

	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
OGS ONE Gas, Inc.	3.12%	3.47%	3.81%	4.08%	3.28%	2.99%	2.81%	2.14%	2.31%	2.29%	2.19%	2.39%
FXAIX Fidelity 500 Index Fund	1.20%	1.11%	1.25%	1.45%	1.69%	1.22%	1.60%	2.06%	2.72%	1.97%	2.52%	2.83%

Drawdowns

OGS vs. FXAIX - Drawdown Comparison

The maximum OGS drawdown since its inception was -33.50%, roughly equal to the maximum FXAIX drawdown of -33.79%. Use the drawdown chart below to compare losses from any high point for OGS and FXAIX.

Drawdown Indicators

	OGS	FXAIX	Difference
Max Drawdown Largest peak-to-trough decline	-33.50%	-33.79%	+0.29%
Max Drawdown (1Y) Largest decline over 1 year	-11.75%	-12.13%	+0.38%
Max Drawdown (5Y) Largest decline over 5 years	-33.50%	-24.50%	-9.00%
Max Drawdown (10Y) Largest decline over 10 years	-33.50%	-33.79%	+0.29%
Current Drawdown Current decline from peak	-1.79%	-8.89%	+7.10%
Average Drawdown Average peak-to-trough decline	-9.71%	-3.83%	-5.88%
Ulcer Index Depth and duration of drawdowns from previous peaks	5.81%	2.50%	+3.31%

Volatility

OGS vs. FXAIX - Volatility Comparison

ONE Gas, Inc. (OGS) has a higher volatility of 4.46% compared to Fidelity 500 Index Fund (FXAIX) at 4.24%. This indicates that OGS's price experiences larger fluctuations and is considered to be riskier than FXAIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	OGS	FXAIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.46%	4.24%	+0.22%
Volatility (6M) Calculated over the trailing 6-month period	10.86%	9.08%	+1.78%
Volatility (1Y) Calculated over the trailing 1-year period	18.07%	18.13%	-0.06%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	23.45%	16.88%	+6.57%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	25.91%	18.03%	+7.88%