VUSTX vs. PRGMX

Last updated Jun 12, 2026

VUSTX (Vanguard Long-Term Treasury Fund Investor Shares) and PRGMX (T. Rowe Price GNMA Fund) are both Government Bonds funds. Over the past 10 years, VUSTX returned -1.30%/yr vs 1.27%/yr for PRGMX. A 0.73 correlation means they provide meaningful diversification when combined. VUSTX charges 0.20%/yr vs 0.58%/yr for PRGMX.

Performance

VUSTX vs. PRGMX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Vanguard Long-Term Treasury Fund Investor Shares (VUSTX) and T. Rowe Price GNMA Fund (PRGMX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, VUSTX achieves a -1.07% return, which is significantly lower than PRGMX's 0.44% return. Over the past 10 years, VUSTX has underperformed PRGMX with an annualized return of -1.30%, while PRGMX has yielded a comparatively higher 1.27% annualized return.

VUSTX

• 1D: -0.26%
• 1M: 0.13%
• YTD: -1.07%
• 6M: -1.20%
• 1Y: 3.68%
• 3Y*: -0.78%
• 5Y*: -5.75%
• 10Y*: -1.30%

PRGMX

• 1D: -0.12%
• 1M: -0.05%
• YTD: 0.44%
• 6M: 1.20%
• 1Y: 6.82%
• 3Y*: 4.71%
• 5Y*: 0.55%
• 10Y*: 1.27%

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

VUSTX vs. PRGMX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
VUSTX Vanguard Long-Term Treasury Fund Investor Shares	-1.07%	5.55%	-6.41%	3.33%	-29.58%	-4.93%	18.20%	14.14%	-1.89%	8.60%
PRGMX T. Rowe Price GNMA Fund	0.44%	8.72%	1.86%	5.62%	-11.45%	-2.18%	4.21%	5.18%	0.58%	1.23%

Correlation

The correlation between VUSTX and PRGMX is 0.82, 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	0.82
Correlation (3Y) Calculated over the trailing 3-year period	0.86
Correlation (5Y) Calculated over the trailing 5-year period	0.80
Correlation (10Y) Calculated over the trailing 10-year period	0.71
Correlation (All Time) Calculated using the full available price history since May 19, 1986	0.73

The correlation between VUSTX and PRGMX shifts across timeframes, from 0.71 (10 years) to 0.86 (3 years), reflecting how their relationship changes across market environments.

Return for Risk

VUSTX vs. PRGMX — Risk / Return Rank

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

VUSTX

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

PRGMX

PRGMX Risk / Return Rank: 54
PRGMX Sharpe Ratio Rank: 54
PRGMX Sortino Ratio Rank: 62
PRGMX Omega Ratio Rank: 54
PRGMX Calmar Ratio Rank: 56
PRGMX Martin Ratio Rank: 44

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.

VUSTX vs. PRGMX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Vanguard Long-Term Treasury Fund Investor Shares (VUSTX) and T. Rowe Price GNMA Fund (PRGMX). 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.

	VUSTX	PRGMX	Difference
Sharpe ratio: Return per unit of total volatility	0.46	1.76	-1.30
Sortino ratio: Return per unit of downside risk	0.71	2.66	-1.94
Omega ratio: Gain probability vs. loss probability	1.08	1.33	-0.24
Calmar ratio: Return relative to maximum drawdown	0.57	2.42	-1.85
Martin ratio: Return relative to average drawdown	1.45	7.85	-6.40

VUSTX vs. PRGMX - Sharpe Ratio Comparison

The current VUSTX Sharpe Ratio is 0.46, which is lower than the PRGMX Sharpe Ratio of 1.76. The chart below compares the historical Sharpe Ratios of VUSTX and PRGMX, 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

VUSTX vs. PRGMX - Drawdown Comparison

The maximum VUSTX drawdown since its inception was -46.37%, which is greater than PRGMX's maximum drawdown of -18.22%. Use the drawdown chart below to compare losses from any high point for VUSTX and PRGMX.

Drawdown Indicators

	VUSTX	PRGMX	Difference
Max Drawdown Largest peak-to-trough decline	-46.37%	-18.22%	-28.15%
Max Drawdown (1Y) Largest decline over 1 year	-7.19%	-3.00%	-4.19%
Max Drawdown (3Y) Largest decline over 3 years	-17.70%	-7.14%	-10.56%
Max Drawdown (5Y) Largest decline over 5 years	-41.45%	-17.30%	-24.15%
Max Drawdown (10Y) Largest decline over 10 years	-46.37%	-18.22%	-28.15%
Current Drawdown Current decline from peak	-37.11%	-1.73%	-35.38%
Average Drawdown Average peak-to-trough decline	-9.36%	-2.24%	-7.12%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.81%	0.92%	+1.89%

Volatility

VUSTX vs. PRGMX - Volatility Comparison

Vanguard Long-Term Treasury Fund Investor Shares (VUSTX) has a higher volatility of 2.51% compared to T. Rowe Price GNMA Fund (PRGMX) at 1.61%. This indicates that VUSTX's price experiences larger fluctuations and is considered to be riskier than PRGMX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	VUSTX	PRGMX	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.51%	1.61%	+0.90%
Volatility (6M) Calculated over the trailing 6-month period	6.08%	3.12%	+2.96%
Volatility (1Y) Calculated over the trailing 1-year period	8.91%	4.13%	+4.78%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	14.60%	6.39%	+8.21%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	13.76%	4.77%	+8.99%

VUSTX vs. PRGMX - Expense Ratio Comparison

VUSTX has a 0.20% expense ratio, which is lower than PRGMX's 0.58% expense ratio.

Dividends

VUSTX vs. PRGMX - Dividend Comparison

VUSTX's dividend yield for the trailing twelve months is around 4.51%, less than PRGMX's 5.01% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
PRGMX T. Rowe Price GNMA Fund	5.01%	4.96%	4.47%	3.54%	1.38%	0.59%	1.44%	2.39%	2.78%	2.98%	2.88%	3.12%
VUSTX Vanguard Long-Term Treasury Fund Investor Shares	4.51%	4.29%	4.03%	3.33%	2.93%	4.21%	10.38%	2.82%	2.82%	2.64%	5.27%	5.52%

Frequently Asked Questions

Can I hold both VUSTX and PRGMX in my portfolio?

VUSTX and PRGMX have a correlation of 0.82, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, VUSTX or PRGMX?

VUSTX has higher volatility (2.51%) compared to PRGMX (1.61%). In terms of maximum drawdown, VUSTX dropped -46.37% vs PRGMX's -18.22%.

Which has better risk-adjusted returns?

PRGMX currently has the higher Sharpe Ratio (1.76 vs 0.46), 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.