FNBGX vs. PRULX

Last updated Jun 5, 2026

FNBGX (Fidelity Long-Term Treasury Bond Index Fund) and PRULX (T. Rowe Price U.S. Treasury Long Term Index Fund) are both Government Bonds funds. Over the past 5 years, FNBGX returned -5.43%/yr vs -5.46%/yr for PRULX. With a 0.99 correlation, they move nearly in lockstep. FNBGX charges 0.03%/yr vs 0.29%/yr for PRULX.

Performance

FNBGX vs. PRULX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Fidelity Long-Term Treasury Bond Index Fund (FNBGX) and T. Rowe Price U.S. Treasury Long Term Index Fund (PRULX). 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 higher than PRULX's -0.90% return.

FNBGX

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

PRULX

• 1D: -0.43%
• 1M: 0.35%
• YTD: -0.90%
• 6M: -0.91%
• 1Y: 4.76%
• 3Y*: -0.24%
• 5Y*: -5.46%
• 10Y*: -0.51%

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

FNBGX vs. PRULX - 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%
PRULX T. Rowe Price U.S. Treasury Long Term Index Fund	-0.90%	6.69%	-5.71%	2.90%	-30.45%	-5.22%	18.34%	22.58%	-1.86%	1.92%

Correlation

The correlation between FNBGX and PRULX is 0.96 - these two move nearly in lockstep. At this level, holding both provides almost no diversification benefit. If you already own one, adding the other does little to reduce portfolio risk.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.96
Correlation (3Y) Calculated over the trailing 3-year period	0.98
Correlation (5Y) Calculated over the trailing 5-year period	0.99
Correlation (All Time) Calculated using the full available price history since Oct 20, 2017	0.99

The correlation between FNBGX and PRULX has been stable across timeframes, ranging from 0.96 to 0.99 - a consistent structural relationship.

Return for Risk

FNBGX vs. PRULX — 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

PRULX

PRULX Risk / Return Rank: 9
PRULX Sharpe Ratio Rank: 9
PRULX Sortino Ratio Rank: 9
PRULX Omega Ratio Rank: 9
PRULX Calmar Ratio Rank: 10
PRULX Martin Ratio Rank: 9

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. PRULX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Fidelity Long-Term Treasury Bond Index Fund (FNBGX) and T. Rowe Price U.S. Treasury Long Term Index Fund (PRULX). 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	PRULX	Difference
Sharpe ratio: Return per unit of total volatility	0.59	0.71	-0.12
Sortino ratio: Return per unit of downside risk	0.90	1.07	-0.17
Omega ratio: Gain probability vs. loss probability	1.10	1.13	-0.02
Calmar ratio: Return relative to maximum drawdown	0.73	0.90	-0.17
Martin ratio: Return relative to average drawdown	1.92	2.41	-0.49
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. PRULX - Sharpe Ratio Comparison

The current FNBGX Sharpe Ratio is 0.59, which is comparable to the PRULX Sharpe Ratio of 0.71. The chart below compares the historical Sharpe Ratios of FNBGX and PRULX, 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	PRULX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	0.59	0.71	-0.12
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	-0.37	-0.38	0.00
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	—	-0.04	—
Sharpe Ratio (All Time) Calculated using the full available price history	-0.08	0.45	-0.53

Drawdowns

FNBGX vs. PRULX - Drawdown Comparison

The maximum FNBGX drawdown since its inception was -46.86%, roughly equal to the maximum PRULX drawdown of -47.40%. Use the drawdown chart below to compare losses from any high point for FNBGX and PRULX.

Drawdown Indicators

	FNBGX	PRULX	Difference
Max Drawdown Largest peak-to-trough decline	-46.86%	-47.40%	+0.54%
Max Drawdown (1Y) Largest decline over 1 year	-7.28%	-7.35%	+0.07%
Max Drawdown (3Y) Largest decline over 3 years	-17.66%	-17.64%	-0.02%
Max Drawdown (5Y) Largest decline over 5 years	-41.54%	-42.35%	+0.81%
Max Drawdown (10Y) Largest decline over 10 years	—	-47.40%	—
Current Drawdown Current decline from peak	-37.51%	-37.21%	-0.30%
Average Drawdown Average peak-to-trough decline	-21.65%	-9.37%	-12.28%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.76%	2.71%	+0.05%

Volatility

FNBGX vs. PRULX - Volatility Comparison

Fidelity Long-Term Treasury Bond Index Fund (FNBGX) and T. Rowe Price U.S. Treasury Long Term Index Fund (PRULX) have volatilities of 2.71% and 2.74%, respectively, indicating that both stocks experience similar levels of price fluctuations. This suggests that the risk associated with both stocks, as measured by volatility, is nearly the same. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	FNBGX	PRULX	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.71%	2.74%	-0.03%
Volatility (6M) Calculated over the trailing 6-month period	6.04%	6.47%	-0.43%
Volatility (1Y) Calculated over the trailing 1-year period	8.99%	9.29%	-0.30%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	14.59%	14.68%	-0.09%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	14.20%	13.98%	+0.22%

FNBGX vs. PRULX - Expense Ratio Comparison

FNBGX has a 0.03% expense ratio, which is lower than PRULX's 0.29% expense ratio.

Dividends

FNBGX vs. PRULX - Dividend Comparison

FNBGX's dividend yield for the trailing twelve months is around 4.01%, less than PRULX's 5.33% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
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%	0.00%	0.00%
PRULX T. Rowe Price U.S. Treasury Long Term Index Fund	5.33%	5.21%	4.88%	3.84%	2.07%	1.72%	20.34%	16.60%	2.62%	2.48%	4.65%	5.09%

Frequently Asked Questions

Can I hold both FNBGX and PRULX in my portfolio?

With a correlation of 0.96, FNBGX and PRULX 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 PRULX?

PRULX has higher volatility (2.74%) compared to FNBGX (2.71%). In terms of maximum drawdown, FNBGX dropped -46.86% vs PRULX's -47.40%.

Which has better risk-adjusted returns?

PRULX currently has the higher Sharpe Ratio (0.71 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.