FNBGX vs. FUTBX

Last updated Jun 5, 2026

FNBGX (Fidelity Long-Term Treasury Bond Index Fund) and FUTBX (Fidelity SAI U.S. Treasury Bond Index Fund) are both Government Bonds funds from Fidelity. Over the past 5 years, FNBGX returned -5.43%/yr vs -0.51%/yr for FUTBX. Their correlation of 0.94 suggests significant overlap in exposure. Both charge a 0.03% expense ratio.

Performance

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

Returns By Period

In the year-to-date period, FNBGX achieves a -0.41% return, which is significantly lower than FUTBX's -0.05% return.

FNBGX

• 1D: -0.44%
• 1M: 0.24%
• YTD: -0.41%
• 6M: -1.25%
• 1Y: 3.67%
• 3Y*: -0.69%
• 5Y*: -5.43%
• 10Y*: —

FUTBX

• 1D: -0.11%
• 1M: 0.03%
• YTD: -0.05%
• 6M: -0.11%
• 1Y: 3.31%
• 3Y*: 2.87%
• 5Y*: -0.51%
• 10Y*: —

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

FNBGX vs. FUTBX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
FNBGX Fidelity Long-Term Treasury Bond Index Fund	-0.41%	5.30%	-6.18%	3.20%	-29.89%	-5.17%	17.58%	14.24%	-1.62%	1.86%
FUTBX Fidelity SAI U.S. Treasury Bond Index Fund	-0.05%	6.12%	0.70%	4.19%	-13.00%	-2.54%	7.76%	7.30%	0.95%	0.05%

Correlation

The correlation between FNBGX and FUTBX 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	0.94
Correlation (5Y) Calculated over the trailing 5-year period	0.94
Correlation (All Time) Calculated using the full available price history since Oct 20, 2017	0.94

The correlation between FNBGX and FUTBX has been stable across timeframes, ranging from 0.91 to 0.94 - a consistent structural relationship.

Return for Risk

FNBGX vs. FUTBX — Risk / Return Rank

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

FNBGX

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

FUTBX

FUTBX Risk / Return Rank: 14
FUTBX Sharpe Ratio Rank: 14
FUTBX Sortino Ratio Rank: 14
FUTBX Omega Ratio Rank: 13
FUTBX Calmar Ratio Rank: 14
FUTBX Martin Ratio Rank: 13

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. FUTBX - 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 SAI U.S. Treasury Bond Index Fund (FUTBX). 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	FUTBX	Difference
Sharpe ratio: Return per unit of total volatility	0.59	1.02	-0.43
Sortino ratio: Return per unit of downside risk	0.90	1.52	-0.61
Omega ratio: Gain probability vs. loss probability	1.10	1.18	-0.07
Calmar ratio: Return relative to maximum drawdown	0.73	1.28	-0.55
Martin ratio: Return relative to average drawdown	1.92	3.72	-1.80
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. FUTBX - Sharpe Ratio Comparison

The current FNBGX Sharpe Ratio is 0.59, which is lower than the FUTBX Sharpe Ratio of 1.02. The chart below compares the historical Sharpe Ratios of FNBGX and FUTBX, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Sharpe Ratios by Period

	FNBGX	FUTBX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	0.59	1.02	-0.43
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	-0.37	-0.09	-0.29
Sharpe Ratio (All Time) Calculated using the full available price history	-0.08	0.25	-0.33

Drawdowns

FNBGX vs. FUTBX - Drawdown Comparison

The maximum FNBGX drawdown since its inception was -46.86%, which is greater than FUTBX's maximum drawdown of -19.69%. Use the drawdown chart below to compare losses from any high point for FNBGX and FUTBX.

Drawdown Indicators

	FNBGX	FUTBX	Difference
Max Drawdown Largest peak-to-trough decline	-46.86%	-19.69%	-27.17%
Max Drawdown (1Y) Largest decline over 1 year	-7.28%	-3.09%	-4.19%
Max Drawdown (3Y) Largest decline over 3 years	-17.66%	-5.42%	-12.24%
Max Drawdown (5Y) Largest decline over 5 years	-41.54%	-17.03%	-24.51%
Current Drawdown Current decline from peak	-37.51%	-7.72%	-29.79%
Average Drawdown Average peak-to-trough decline	-21.65%	-6.96%	-14.69%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.76%	1.05%	+1.71%

Volatility

FNBGX vs. FUTBX - Volatility Comparison

Fidelity Long-Term Treasury Bond Index Fund (FNBGX) has a higher volatility of 2.71% compared to Fidelity SAI U.S. Treasury Bond Index Fund (FUTBX) at 1.15%. This indicates that FNBGX's price experiences larger fluctuations and is considered to be riskier than FUTBX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	FNBGX	FUTBX	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.71%	1.15%	+1.56%
Volatility (6M) Calculated over the trailing 6-month period	6.04%	2.72%	+3.32%
Volatility (1Y) Calculated over the trailing 1-year period	8.99%	3.86%	+5.13%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	14.59%	5.81%	+8.78%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	14.20%	5.15%	+9.05%

FNBGX vs. FUTBX - Expense Ratio Comparison

Both FNBGX and FUTBX have an expense ratio of 0.03%, making them cost-effective options compared to the broader market, where average expense ratios typically range from 0.3% to 0.9%.

Dividends

FNBGX vs. FUTBX - Dividend Comparison

FNBGX's dividend yield for the trailing twelve months is around 4.01%, more than FUTBX's 3.65% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017
FNBGX Fidelity Long-Term Treasury Bond Index Fund	4.01%	3.88%	3.75%	3.20%	2.26%	2.47%	3.96%	2.63%	2.93%	0.70%
FUTBX Fidelity SAI U.S. Treasury Bond Index Fund	3.65%	3.43%	2.90%	2.12%	1.12%	0.86%	4.54%	2.75%	2.05%	1.65%

Frequently Asked Questions

Can I hold both FNBGX and FUTBX in my portfolio?

With a correlation of 0.91, FNBGX and FUTBX 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 FUTBX?

FNBGX has higher volatility (2.71%) compared to FUTBX (1.15%). In terms of maximum drawdown, FNBGX dropped -46.86% vs FUTBX's -19.69%.

Which has better risk-adjusted returns?

FUTBX currently has the higher Sharpe Ratio (1.02 vs 0.59), 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.