PRGMX vs. CMPGX

Last updated Jun 5, 2026

PRGMX (T. Rowe Price GNMA Fund) and CMPGX (Principal Government & High Quality Bond Fund) are both Government Bonds funds. Over the past 10 years, PRGMX returned 1.28%/yr vs 0.58%/yr for CMPGX. Their correlation of 0.85 suggests significant overlap in exposure. PRGMX charges 0.58%/yr vs 0.78%/yr for CMPGX.

Performance

PRGMX vs. CMPGX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in T. Rowe Price GNMA Fund (PRGMX) and Principal Government & High Quality Bond Fund (CMPGX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, PRGMX achieves a 0.69% return, which is significantly higher than CMPGX's 0.08% return. Over the past 10 years, PRGMX has outperformed CMPGX with an annualized return of 1.28%, while CMPGX has yielded a comparatively lower 0.58% annualized return.

PRGMX

• 1D: -0.24%
• 1M: 0.07%
• YTD: 0.69%
• 6M: 1.32%
• 1Y: 6.95%
• 3Y*: 4.75%
• 5Y*: 0.62%
• 10Y*: 1.28%

CMPGX

• 1D: -0.22%
• 1M: -0.01%
• YTD: 0.08%
• 6M: 0.28%
• 1Y: 5.16%
• 3Y*: 3.43%
• 5Y*: -0.57%
• 10Y*: 0.58%

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

PRGMX vs. CMPGX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
PRGMX T. Rowe Price GNMA Fund	0.69%	8.72%	1.86%	5.62%	-11.45%	-2.18%	4.21%	5.18%	0.58%	1.23%
CMPGX Principal Government & High Quality Bond Fund	0.08%	7.56%	0.46%	3.98%	-12.34%	-1.80%	2.50%	6.12%	0.52%	1.36%

Correlation

The correlation between PRGMX and CMPGX is 0.89, 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	0.89
Correlation (3Y) Calculated over the trailing 3-year period	0.94
Correlation (5Y) Calculated over the trailing 5-year period	0.94
Correlation (10Y) Calculated over the trailing 10-year period	0.88
Correlation (All Time) Calculated using the full available price history since Jan 3, 1986	0.85

The correlation between PRGMX and CMPGX has been stable across timeframes, ranging from 0.85 to 0.94 - a consistent structural relationship.

Return for Risk

PRGMX vs. CMPGX — Risk / Return Rank

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

PRGMX

PRGMX Risk / Return Rank: 43
PRGMX Sharpe Ratio Rank: 40
PRGMX Sortino Ratio Rank: 45
PRGMX Omega Ratio Rank: 42
PRGMX Calmar Ratio Rank: 46
PRGMX Martin Ratio Rank: 41

CMPGX

CMPGX Risk / Return Rank: 24
CMPGX Sharpe Ratio Rank: 23
CMPGX Sortino Ratio Rank: 24
CMPGX Omega Ratio Rank: 23
CMPGX Calmar Ratio Rank: 24
CMPGX Martin Ratio Rank: 25

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.

PRGMX vs. CMPGX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for T. Rowe Price GNMA Fund (PRGMX) and Principal Government & High Quality Bond Fund (CMPGX). 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.

	PRGMX	CMPGX	Difference
Sharpe ratio: Return per unit of total volatility	1.82	1.35	+0.47
Sortino ratio: Return per unit of downside risk	2.76	1.98	+0.78
Omega ratio: Gain probability vs. loss probability	1.34	1.24	+0.10
Calmar ratio: Return relative to maximum drawdown	2.56	1.74	+0.82
Martin ratio: Return relative to average drawdown	8.54	5.88	+2.65
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

PRGMX vs. CMPGX - Sharpe Ratio Comparison

The current PRGMX Sharpe Ratio is 1.82, which is higher than the CMPGX Sharpe Ratio of 1.35. The chart below compares the historical Sharpe Ratios of PRGMX and CMPGX, 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

	PRGMX	CMPGX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.82	1.35	+0.47
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.10	-0.09	+0.18
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.27	0.12	+0.15
Sharpe Ratio (All Time) Calculated using the full available price history	0.93	0.82	+0.11

Drawdowns

PRGMX vs. CMPGX - Drawdown Comparison

The maximum PRGMX drawdown since its inception was -18.22%, smaller than the maximum CMPGX drawdown of -19.56%. Use the drawdown chart below to compare losses from any high point for PRGMX and CMPGX.

Drawdown Indicators

	PRGMX	CMPGX	Difference
Max Drawdown Largest peak-to-trough decline	-18.22%	-19.56%	+1.34%
Max Drawdown (1Y) Largest decline over 1 year	-3.00%	-3.39%	+0.39%
Max Drawdown (3Y) Largest decline over 3 years	-7.14%	-8.19%	+1.05%
Max Drawdown (5Y) Largest decline over 5 years	-17.30%	-19.17%	+1.87%
Max Drawdown (10Y) Largest decline over 10 years	-18.22%	-19.56%	+1.34%
Current Drawdown Current decline from peak	-1.49%	-3.59%	+2.10%
Average Drawdown Average peak-to-trough decline	-2.24%	-2.42%	+0.18%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.89%	1.00%	-0.11%

Volatility

PRGMX vs. CMPGX - Volatility Comparison

T. Rowe Price GNMA Fund (PRGMX) and Principal Government & High Quality Bond Fund (CMPGX) have volatilities of 1.66% and 1.64%, 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

	PRGMX	CMPGX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.66%	1.64%	+0.02%
Volatility (6M) Calculated over the trailing 6-month period	3.10%	3.17%	-0.07%
Volatility (1Y) Calculated over the trailing 1-year period	4.20%	4.37%	-0.17%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	6.38%	6.65%	-0.27%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	4.77%	4.97%	-0.20%

PRGMX vs. CMPGX - Expense Ratio Comparison

PRGMX has a 0.58% expense ratio, which is lower than CMPGX's 0.78% expense ratio.

Dividends

PRGMX vs. CMPGX - Dividend Comparison

PRGMX's dividend yield for the trailing twelve months is around 5.00%, more than CMPGX's 3.61% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
CMPGX Principal Government & High Quality Bond Fund	3.61%	3.44%	2.84%	2.19%	1.35%	1.08%	2.00%	2.43%	2.65%	3.30%	3.76%	2.96%
PRGMX T. Rowe Price GNMA Fund	5.00%	4.96%	4.47%	3.54%	1.38%	0.59%	1.44%	2.39%	2.78%	2.98%	2.88%	3.12%

Frequently Asked Questions

Can I hold both PRGMX and CMPGX in my portfolio?

PRGMX and CMPGX have a correlation of 0.89, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, PRGMX or CMPGX?

PRGMX has higher volatility (1.66%) compared to CMPGX (1.64%). In terms of maximum drawdown, PRGMX dropped -18.22% vs CMPGX's -19.56%.

Which has better risk-adjusted returns?

PRGMX currently has the higher Sharpe Ratio (1.82 vs 1.35), 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.