PRULX vs. VSBIX

Last updated Jun 25, 2026

PRULX (T. Rowe Price U.S. Treasury Long Term Index Fund) and VSBIX (Vanguard Short-Term Treasury Index Fund Institutional Shares) are both Government Bonds funds. Over the past 10 years, PRULX returned -0.61%/yr vs 1.74%/yr for VSBIX. A 0.60 correlation means they provide meaningful diversification when combined. PRULX charges 0.29%/yr vs 0.05%/yr for VSBIX.

Performance

PRULX vs. VSBIX - 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 Vanguard Short-Term Treasury Index Fund Institutional Shares (VSBIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, PRULX achieves a -0.19% return, which is significantly lower than VSBIX's 0.48% return. Over the past 10 years, PRULX has underperformed VSBIX with an annualized return of -0.61%, while VSBIX has yielded a comparatively higher 1.74% annualized return.

PRULX

• 1D: 0.14%
• 1M: 2.38%
• YTD: -0.19%
• 6M: 0.21%
• 1Y: 4.62%
• 3Y*: -0.25%
• 5Y*: -5.76%
• 10Y*: -0.61%

VSBIX

• 1D: 0.04%
• 1M: 0.19%
• YTD: 0.48%
• 6M: 0.61%
• 1Y: 2.90%
• 3Y*: 4.33%
• 5Y*: 1.91%
• 10Y*: 1.74%

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

PRULX vs. VSBIX - 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	-0.19%	6.69%	-5.71%	2.90%	-30.45%	-5.22%	18.34%	22.58%	-1.86%	8.23%
VSBIX Vanguard Short-Term Treasury Index Fund Institutional Shares	0.48%	5.11%	4.37%	4.28%	-3.87%	-0.67%	3.11%	3.53%	1.52%	0.40%

Correlation

The correlation between PRULX and VSBIX is 0.66, which is moderate. They share some common price drivers but move independently often enough to provide real diversification benefit when combined.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.66
Correlation (3Y) Calculated over the trailing 3-year period	0.64
Correlation (5Y) Calculated over the trailing 5-year period	0.63
Correlation (10Y) Calculated over the trailing 10-year period	0.61
Correlation (All Time) Calculated using the full available price history since Nov 23, 2009	0.60

The correlation between PRULX and VSBIX has been stable across timeframes, ranging from 0.60 to 0.66 - a consistent structural relationship.

Return for Risk

PRULX vs. VSBIX — Risk / Return Rank

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

PRULX

PRULX Risk / Return Rank: 8
PRULX Sharpe Ratio Rank: 8
PRULX Sortino Ratio Rank: 8
PRULX Omega Ratio Rank: 8
PRULX Calmar Ratio Rank: 9
PRULX Martin Ratio Rank: 8

VSBIX

VSBIX Risk / Return Rank: 82
VSBIX Sharpe Ratio Rank: 75
VSBIX Sortino Ratio Rank: 84
VSBIX Omega Ratio Rank: 81
VSBIX Calmar Ratio Rank: 84
VSBIX Martin Ratio Rank: 85

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.

PRULX vs. VSBIX - 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 Vanguard Short-Term Treasury Index Fund Institutional Shares (VSBIX). 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	VSBIX	Difference
Sharpe ratio: Return per unit of total volatility	0.61	2.31	-1.70
Sortino ratio: Return per unit of downside risk	0.93	3.67	-2.74
Omega ratio: Gain probability vs. loss probability	1.11	1.48	-0.37
Calmar ratio: Return relative to maximum drawdown	0.75	3.71	-2.95
Martin ratio: Return relative to average drawdown	1.90	14.78	-12.88

PRULX vs. VSBIX - Sharpe Ratio Comparison

The current PRULX Sharpe Ratio is 0.61, which is lower than the VSBIX Sharpe Ratio of 2.31. The chart below compares the historical Sharpe Ratios of PRULX and VSBIX, 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. VSBIX - Drawdown Comparison

The maximum PRULX drawdown since its inception was -47.40%, which is greater than VSBIX's maximum drawdown of -5.74%. Use the drawdown chart below to compare losses from any high point for PRULX and VSBIX.

Drawdown Indicators

	PRULX	VSBIX	Difference
Max Drawdown Largest peak-to-trough decline	-47.40%	-5.74%	-41.66%
Max Drawdown (1Y) Largest decline over 1 year	-7.35%	-0.81%	-6.54%
Max Drawdown (3Y) Largest decline over 3 years	-17.64%	-0.81%	-16.83%
Max Drawdown (5Y) Largest decline over 5 years	-42.35%	-5.74%	-36.61%
Max Drawdown (10Y) Largest decline over 10 years	-47.40%	-5.74%	-41.66%
Current Drawdown Current decline from peak	-36.76%	-0.24%	-36.52%
Average Drawdown Average peak-to-trough decline	-9.41%	-0.59%	-8.82%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.87%	0.20%	+2.67%

Volatility

PRULX vs. VSBIX - Volatility Comparison

T. Rowe Price U.S. Treasury Long Term Index Fund (PRULX) has a higher volatility of 2.22% compared to Vanguard Short-Term Treasury Index Fund Institutional Shares (VSBIX) at 0.49%. This indicates that PRULX's price experiences larger fluctuations and is considered to be riskier than VSBIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	PRULX	VSBIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.22%	0.49%	+1.73%
Volatility (6M) Calculated over the trailing 6-month period	6.49%	0.94%	+5.55%
Volatility (1Y) Calculated over the trailing 1-year period	9.02%	1.30%	+7.72%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	14.63%	1.96%	+12.67%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	13.96%	1.54%	+12.42%

PRULX vs. VSBIX - Expense Ratio Comparison

PRULX has a 0.29% expense ratio, which is higher than VSBIX's 0.05% expense ratio.

Dividends

PRULX vs. VSBIX - Dividend Comparison

PRULX's dividend yield for the trailing twelve months is around 5.29%, more than VSBIX's 3.87% 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	5.29%	5.21%	4.88%	3.84%	2.07%	1.72%	20.34%	16.60%	2.62%	2.48%	4.65%	5.09%
VSBIX Vanguard Short-Term Treasury Index Fund Institutional Shares	3.87%	3.99%	4.52%	3.31%	1.14%	0.65%	1.74%	2.28%	1.81%	1.11%	0.80%	0.74%

Frequently Asked Questions

Can I hold both PRULX and VSBIX in my portfolio?

PRULX and VSBIX have a correlation of 0.66, 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 VSBIX?

PRULX has higher volatility (2.22%) compared to VSBIX (0.49%). In terms of maximum drawdown, PRULX dropped -47.40% vs VSBIX's -5.74%.

Which has better risk-adjusted returns?

VSBIX currently has the higher Sharpe Ratio (2.31 vs 0.61), 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.