PRULX vs. RFBAX

Last updated Aug 5, 2026

PRULX (T. Rowe Price U.S. Treasury Long Term Index Fund) and RFBAX (Davis Government Bond Fund) are both Government Bonds funds. Over the past 10 years, PRULX returned -1.14%/yr vs 1.07%/yr for RFBAX. Their 0.56 correlation means they have sometimes moved together and sometimes differently. PRULX charges 0.29%/yr vs 1.00%/yr for RFBAX.

Performance

PRULX vs. RFBAX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in T. Rowe Price U.S. Treasury Long Term Index Fund (PRULX) and Davis Government Bond Fund (RFBAX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, PRULX achieves a -3.51% return, which is significantly lower than RFBAX's 0.94% return. Over the past 10 years, PRULX has underperformed RFBAX with an annualized return of -1.14%, while RFBAX has yielded a comparatively higher 1.07% annualized return.

PRULX

• 1D: 0.30%
• 1M: -3.42%
• 6M: -2.88%
• YTD: -3.51%
• 1Y: -0.82%
• 3Y*: 0.42%
• 5Y*: -7.37%
• 10Y*: -1.14%
• ALL TIME*: 4.98%

RFBAX

• 1D: 0.00%
• 1M: -0.19%
• 6M: 0.88%
• YTD: 0.94%
• 1Y: 2.41%
• 3Y*: 3.91%
• 5Y*: 1.30%
• 10Y*: 1.07%
• ALL TIME*: 2.61%

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

Liquidity Comparison

Position	Avg. Volume Value (2W)	Avg. Volume Value (1M)	Avg. Volume Value (3M)
PRULX T. Rowe Price U.S. Treasury Long Term Index Fund	$0.00	$0.00	$0.00
RFBAX Davis Government Bond Fund	$0.00	$0.00	$0.00

PRULX vs. RFBAX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
PRULX T. Rowe Price U.S. Treasury Long Term Index Fund	-3.51%	6.69%	-5.71%	2.90%	-30.45%	-5.22%	18.34%	22.58%	-1.86%	8.23%
RFBAX Davis Government Bond Fund	0.94%	4.49%	4.33%	3.63%	-5.29%	-1.48%	1.69%	3.23%	0.42%	0.21%

Correlation

The correlation between PRULX and RFBAX is 0.32, which is low. Their historical price movements had little consistent relationship.

	Correlation
Correlation (1Y) Focuses on recent behavior, but can change the most.	0.32
Correlation (3Y) Balances recent behavior with more history.	0.47
Correlation (5Y) Shows whether the relationship held over a longer period.	0.54
Correlation (10Y) Provides a long-term view across more market conditions.	0.45
Correlation (All Time) Calculated using the full available price history since Jan 3, 1995	0.56

Over the past year, the correlation between PRULX and RFBAX has dropped to 0.32 - well below their long-term average of 0.56, suggesting their price drivers have been diverging.

Return for Risk

PRULX vs. RFBAX — Risk / Return Rank

Compare historical risk-adjusted metric ranks over the past 12 months.

PRULX

PRULX Risk / Return Rank: 3
PRULX Sharpe Ratio Rank: 3
PRULX Sortino Ratio Rank: 3
PRULX Omega Ratio Rank: 3
PRULX Calmar Ratio Rank: 3
PRULX Martin Ratio Rank: 3

RFBAX

RFBAX Risk / Return Rank: 70
RFBAX Sharpe Ratio Rank: 43
RFBAX Sortino Ratio Rank: 53
RFBAX Omega Ratio Rank: 79
RFBAX Calmar Ratio Rank: 87
RFBAX Martin Ratio Rank: 88

The rank (0–100) uses a weighted average of the Sharpe, Sortino, Omega, Calmar, and Martin percentile ranks for the trailing 12 months. Higher means stronger historical risk-adjusted performance within the peer group.

PRULX vs. RFBAX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for T. Rowe Price U.S. Treasury Long Term Index Fund (PRULX) and Davis Government Bond Fund (RFBAX). 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.

	PRULX	RFBAX	Difference
Sharpe ratio: Return per unit of total volatility	-0.08	1.43	-1.51
Sortino ratio: Return per unit of downside risk	-0.05	2.27	-2.32
Omega ratio: Gain probability vs. loss probability	0.99	1.38	-0.39
Calmar ratio: Return relative to maximum drawdown	-0.10	3.40	-3.49
Martin ratio: Return relative to average drawdown	-0.22	12.51	-12.73

PRULX vs. RFBAX - Sharpe Ratio Comparison

The current PRULX Sharpe Ratio is -0.08, which is lower than the RFBAX Sharpe Ratio of 1.43. The chart below compares the historical Sharpe Ratios of PRULX and RFBAX, 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

PRULX vs. RFBAX - Drawdown Comparison

The maximum PRULX drawdown since its inception was -47.40%, which is greater than RFBAX's maximum drawdown of -8.03%. Use the drawdown chart below to compare losses from any high point for PRULX and RFBAX.

Drawdown Indicators

	PRULX	RFBAX	Difference
Max Drawdown Largest peak-to-trough decline	-47.40%	-8.03%	-39.37%
Max Drawdown (1Y) Largest decline over 1 year	-7.23%	-0.77%	-6.46%
Max Drawdown (3Y) Largest decline over 3 years	-13.44%	-0.88%	-12.56%
Max Drawdown (5Y) Largest decline over 5 years	-42.35%	-7.50%	-34.85%
Max Drawdown (10Y) Largest decline over 10 years	-47.40%	-8.03%	-39.37%
Current Drawdown Current decline from peak	-38.86%	-0.39%	-38.47%
Average Drawdown Average peak-to-trough decline	-9.49%	-1.18%	-8.31%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.20%	0.21%	+2.99%

Volatility

PRULX vs. RFBAX - Volatility Comparison

T. Rowe Price U.S. Treasury Long Term Index Fund (PRULX) has a higher volatility of 2.27% compared to Davis Government Bond Fund (RFBAX) at 0.53%. This indicates that PRULX's price experiences larger fluctuations and is considered to be riskier than RFBAX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	PRULX	RFBAX	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.27%	0.53%	+1.74%
Volatility (6M) Calculated over the trailing 6-month period	6.53%	1.35%	+5.18%
Volatility (1Y) Calculated over the trailing 1-year period	8.82%	1.84%	+6.98%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	14.55%	2.12%	+12.43%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	13.92%	1.79%	+12.13%

PRULX vs. RFBAX - Expense Ratio Comparison

PRULX has a 0.29% expense ratio, which is lower than RFBAX's 1.00% expense ratio.

Dividends

PRULX vs. RFBAX - Dividend Comparison

PRULX's dividend yield for the trailing twelve months is around 5.18%, more than RFBAX's 2.78% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
PRULX T. Rowe Price U.S. Treasury Long Term Index Fund	5.18%	5.21%	4.88%	3.84%	2.07%	1.72%	20.34%	16.60%	2.62%	2.48%	4.65%	5.09%
RFBAX Davis Government Bond Fund	2.78%	3.01%	3.23%	2.15%	0.80%	0.57%	0.93%	1.67%	1.17%	0.59%	0.68%	0.75%

Frequently Asked Questions

Can I hold both PRULX and RFBAX in my portfolio?

PRULX and RFBAX have a correlation of 0.32, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, PRULX or RFBAX?

PRULX has higher volatility (2.27%) compared to RFBAX (0.53%). In terms of maximum drawdown, PRULX dropped -47.40% vs RFBAX's -8.03%.

Which has better risk-adjusted returns?

RFBAX currently has the higher Sharpe Ratio (1.43 vs -0.08), 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.