FNBGX vs. FXNAX

Last updated Jun 24, 2026

FNBGX (Fidelity Long-Term Treasury Bond Index Fund) and FXNAX (Fidelity U.S. Bond Index Fund) are both mutual funds - FNBGX is a Government Bonds fund managed by Fidelity, while FXNAX is a Total Bond Market fund tracking the Bloomberg U.S. Aggregate Bond Index. Over the past 5 years, FNBGX returned -5.72%/yr vs -0.05%/yr for FXNAX. Their correlation of 0.91 suggests significant overlap in exposure. FNBGX charges 0.03%/yr vs 0.03%/yr for FXNAX.

Performance

FNBGX vs. FXNAX - 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 U.S. Bond Index Fund (FXNAX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, FNBGX achieves a 0.13% return, which is significantly higher than FXNAX's 0.11% return.

FNBGX

• 1D: -0.65%
• 1M: 1.91%
• YTD: 0.13%
• 6M: 0.25%
• 1Y: 4.01%
• 3Y*: -0.79%
• 5Y*: -5.72%
• 10Y*: —

FXNAX

• 1D: -0.29%
• 1M: 0.61%
• YTD: 0.11%
• 6M: 0.43%
• 1Y: 4.25%
• 3Y*: 3.88%
• 5Y*: -0.05%
• 10Y*: 1.44%

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

FNBGX vs. FXNAX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
FNBGX Fidelity Long-Term Treasury Bond Index Fund	0.13%	5.30%	-6.18%	3.20%	-29.89%	-5.17%	17.58%	14.24%	-1.62%	1.86%
FXNAX Fidelity U.S. Bond Index Fund	0.11%	7.14%	1.35%	5.82%	-13.55%	-2.10%	7.63%	8.50%	0.04%	0.38%

Correlation

The correlation between FNBGX and FXNAX is 0.91, indicating a strong positive relationship between their price movements. Combining them offers limited diversification - they tend to fall together during downturns.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.91
Correlation (3Y) Calculated over the trailing 3-year period	0.93
Correlation (5Y) Calculated over the trailing 5-year period	0.93
Correlation (All Time) Calculated using the full available price history since Oct 19, 2017	0.91

The correlation between FNBGX and FXNAX has been stable across timeframes, ranging from 0.91 to 0.93 - a consistent structural relationship.

Return for Risk

FNBGX vs. FXNAX — Risk / Return Rank

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

FNBGX

FNBGX Risk / Return Rank: 6
FNBGX Sharpe Ratio Rank: 7
FNBGX Sortino Ratio Rank: 7
FNBGX Omega Ratio Rank: 6
FNBGX Calmar Ratio Rank: 7
FNBGX Martin Ratio Rank: 6

FXNAX

FXNAX Risk / Return Rank: 18
FXNAX Sharpe Ratio Rank: 18
FXNAX Sortino Ratio Rank: 20
FXNAX Omega Ratio Rank: 17
FXNAX Calmar Ratio Rank: 20
FXNAX Martin Ratio Rank: 18

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. FXNAX - 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 U.S. Bond Index Fund (FXNAX). 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.

Values are calculated on a 1-year rolling basis and updated daily. Risk-adjusted metrics are more stable over longer periods — use the period switch above to explore them.

	FNBGX	FXNAX	Difference
Sharpe ratio: Return per unit of total volatility	0.50	1.14	-0.64
Sortino ratio: Return per unit of downside risk	0.78	1.73	-0.95
Omega ratio: Gain probability vs. loss probability	1.09	1.20	-0.11
Calmar ratio: Return relative to maximum drawdown	0.60	1.52	-0.92
Martin ratio: Return relative to average drawdown	1.51	4.36	-2.86

FNBGX vs. FXNAX - Sharpe Ratio Comparison

The current FNBGX Sharpe Ratio is 0.50, which is lower than the FXNAX Sharpe Ratio of 1.14. The chart below compares the historical Sharpe Ratios of FNBGX and FXNAX, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Drawdowns

FNBGX vs. FXNAX - Drawdown Comparison

The maximum FNBGX drawdown since its inception was -46.86%, which is greater than FXNAX's maximum drawdown of -19.51%. Use the drawdown chart below to compare losses from any high point for FNBGX and FXNAX.

Drawdown Indicators

	FNBGX	FXNAX	Difference
Max Drawdown Largest peak-to-trough decline	-46.86%	-19.51%	-27.35%
Max Drawdown (1Y) Largest decline over 1 year	-7.28%	-2.94%	-4.34%
Max Drawdown (3Y) Largest decline over 3 years	-17.66%	-6.16%	-11.50%
Max Drawdown (5Y) Largest decline over 5 years	-41.54%	-18.54%	-23.00%
Max Drawdown (10Y) Largest decline over 10 years	—	-19.51%	—
Current Drawdown Current decline from peak	-37.17%	-3.17%	-34.00%
Average Drawdown Average peak-to-trough decline	-21.73%	-3.86%	-17.87%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.89%	1.02%	+1.87%

Volatility

FNBGX vs. FXNAX - Volatility Comparison

Fidelity Long-Term Treasury Bond Index Fund (FNBGX) has a higher volatility of 2.09% compared to Fidelity U.S. Bond Index Fund (FXNAX) at 1.16%. This indicates that FNBGX's price experiences larger fluctuations and is considered to be riskier than FXNAX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	FNBGX	FXNAX	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.09%	1.16%	+0.93%
Volatility (6M) Calculated over the trailing 6-month period	6.16%	2.90%	+3.26%
Volatility (1Y) Calculated over the trailing 1-year period	8.71%	3.92%	+4.79%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	14.54%	6.08%	+8.46%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	14.17%	5.01%	+9.16%

FNBGX vs. FXNAX - Expense Ratio Comparison

FNBGX has a 0.03% expense ratio, which is higher than FXNAX's 0.03% 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%.

Dividends

FNBGX vs. FXNAX - Dividend Comparison

FNBGX's dividend yield for the trailing twelve months is around 3.99%, more than FXNAX's 3.72% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FNBGX Fidelity Long-Term Treasury Bond Index Fund	3.99%	3.88%	3.75%	3.20%	2.26%	2.47%	3.96%	2.63%	2.93%	0.70%	0.00%	0.00%
FXNAX Fidelity U.S. Bond Index Fund	3.72%	3.58%	3.40%	3.15%	1.81%	1.74%	2.92%	2.68%	2.74%	2.57%	2.76%	2.52%

Frequently Asked Questions

Can I hold both FNBGX and FXNAX in my portfolio?

With a correlation of 0.91, FNBGX and FXNAX move almost identically. Holding both adds very little diversification - you're essentially doubling your position in the same market segment. Choosing one is usually more capital-efficient.

Which is riskier, FNBGX or FXNAX?

FNBGX has higher volatility (2.09%) compared to FXNAX (1.16%). In terms of maximum drawdown, FNBGX dropped -46.86% vs FXNAX's -19.51%.

Which has better risk-adjusted returns?

FXNAX currently has the higher Sharpe Ratio (1.14 vs 0.50), meaning it's delivered slightly more return per unit of risk over the trailing 12 months. However, this ranking shifts over time - use the Risk/Return Score above for a more comprehensive view that combines Sharpe, Sortino, and other measures used by quantitative funds.