FNBGX vs. FXAIX

Last updated Apr 1, 2026

Compare and contrast key facts about Fidelity Long-Term Treasury Bond Index Fund (FNBGX) and Fidelity 500 Index Fund (FXAIX).

FNBGX is managed by Fidelity. It was launched on Dec 20, 2005. 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

FNBGX vs. FXAIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Fidelity Long-Term Treasury Bond Index Fund (FNBGX) and Fidelity 500 Index Fund (FXAIX). The values are adjusted to include any dividend payments, if applicable.

FNBGX vs. FXAIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
FNBGX Fidelity Long-Term Treasury Bond Index Fund	-0.35%	5.30%	-6.18%	3.20%	-29.89%	-5.17%	17.58%	14.24%	-1.62%	1.86%
FXAIX Fidelity 500 Index Fund	-7.05%	17.84%	25.01%	26.29%	-18.14%	28.71%	18.42%	31.48%	-4.43%	4.78%

Returns By Period

In the year-to-date period, FNBGX achieves a -0.35% return, which is significantly higher than FXAIX's -7.05% return.

FNBGX

• 1D: 1.21%
• 1M: -4.27%
• YTD: -0.35%
• 6M: -0.77%
• 1Y: 0.13%
• 3Y*: -1.65%
• 5Y*: -4.78%
• 10Y*: —

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)

FNBGX vs. FXAIX - Expense Ratio Comparison

FNBGX has a 0.03% expense ratio, which is higher than FXAIX's 0.02% expense ratio. However, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.

FNBGX

Fidelity Long-Term Treasury Bond Index Fund

FXAIX

Fidelity 500 Index Fund

Return for Risk

FNBGX vs. FXAIX — Risk / Return Rank

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

FNBGX

FNBGX Risk / Return Rank: 9
FNBGX Sharpe Ratio Rank: 8
FNBGX Sortino Ratio Rank: 7
FNBGX Omega Ratio Rank: 7
FNBGX Calmar Ratio Rank: 12
FNBGX Martin Ratio Rank: 10

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.

FNBGX vs. FXAIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Fidelity Long-Term Treasury Bond Index Fund (FNBGX) 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.

	FNBGX	FXAIX	Difference
Sharpe ratio Return per unit of total volatility	0.12	0.84	-0.72
Sortino ratio Return per unit of downside risk	0.23	1.30	-1.07
Omega ratio Gain probability vs. loss probability	1.03	1.20	-0.17
Calmar ratio Return relative to maximum drawdown	0.30	1.05	-0.76
Martin ratio Return relative to average drawdown	0.66	5.13	-4.47
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

FNBGX vs. FXAIX - Sharpe Ratio Comparison

The current FNBGX Sharpe Ratio is 0.12, which is lower than the FXAIX Sharpe Ratio of 0.84. The chart below compares the historical Sharpe Ratios of FNBGX 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

	FNBGX	FXAIX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	0.12	0.84	-0.72
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	-0.33	0.68	-1.01
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	—	0.77	—
Sharpe Ratio (All Time) Calculated using the full available price history	-0.08	0.75	-0.83

Correlation

The correlation between FNBGX and FXAIX is -0.09. This indicates that the assets' prices tend to move in opposite directions. Negative correlation can be particularly beneficial for diversification and risk management, as one asset may offset the losses of the other during market fluctuations.

Dividends

FNBGX vs. FXAIX - Dividend Comparison

FNBGX's dividend yield for the trailing twelve months is around 3.60%, more than FXAIX's 1.20% yield.

	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FNBGX Fidelity Long-Term Treasury Bond Index Fund	3.60%	3.88%	3.75%	3.20%	2.26%	2.47%	3.96%	2.63%	2.93%	0.70%	0.00%	0.00%
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

FNBGX vs. FXAIX - Drawdown Comparison

The maximum FNBGX drawdown since its inception was -46.86%, which is greater than FXAIX's maximum drawdown of -33.79%. Use the drawdown chart below to compare losses from any high point for FNBGX and FXAIX.

Drawdown Indicators

	FNBGX	FXAIX	Difference
Max Drawdown Largest peak-to-trough decline	-46.86%	-33.79%	-13.07%
Max Drawdown (1Y) Largest decline over 1 year	-8.75%	-12.13%	+3.38%
Max Drawdown (5Y) Largest decline over 5 years	-41.54%	-24.50%	-17.04%
Max Drawdown (10Y) Largest decline over 10 years	—	-33.79%	—
Current Drawdown Current decline from peak	-37.47%	-8.89%	-28.58%
Average Drawdown Average peak-to-trough decline	-21.32%	-3.83%	-17.49%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.97%	2.50%	+1.47%

Volatility

FNBGX vs. FXAIX - Volatility Comparison

The current volatility for Fidelity Long-Term Treasury Bond Index Fund (FNBGX) is 3.58%, while Fidelity 500 Index Fund (FXAIX) has a volatility of 4.24%. This indicates that FNBGX experiences smaller price fluctuations and is considered to be less risky than FXAIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	FNBGX	FXAIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.58%	4.24%	-0.66%
Volatility (6M) Calculated over the trailing 6-month period	6.05%	9.08%	-3.03%
Volatility (1Y) Calculated over the trailing 1-year period	10.49%	18.13%	-7.64%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	14.61%	16.88%	-2.27%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	14.30%	18.03%	-3.73%