MWUSX vs. PRTBX

Last updated Jun 4, 2026

MWUSX (Metropolitan West Ultra Short Bond Fund) and PRTBX (Permanent Portfolio Short-Term Treasury Portfolio) are both Ultrashort Bond funds. Over the past 10 years, MWUSX returned 1.93%/yr vs 1.26%/yr for PRTBX. At a 0.19 correlation, their price movements are largely independent. MWUSX charges 0.50%/yr vs 0.65%/yr for PRTBX.

Performance

MWUSX vs. PRTBX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Metropolitan West Ultra Short Bond Fund (MWUSX) and Permanent Portfolio Short-Term Treasury Portfolio (PRTBX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, MWUSX achieves a 1.16% return, which is significantly higher than PRTBX's 0.76% return. Over the past 10 years, MWUSX has outperformed PRTBX with an annualized return of 1.93%, while PRTBX has yielded a comparatively lower 1.26% annualized return.

MWUSX

• 1D: 0.00%
• 1M: 0.31%
• YTD: 1.16%
• 6M: 1.63%
• 1Y: 4.43%
• 3Y*: 4.45%
• 5Y*: 2.33%
• 10Y*: 1.93%

PRTBX

• 1D: 0.00%
• 1M: 0.18%
• YTD: 0.76%
• 6M: 1.03%
• 1Y: 3.18%
• 3Y*: 3.85%
• 5Y*: 1.98%
• 10Y*: 1.26%

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

MWUSX vs. PRTBX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
MWUSX Metropolitan West Ultra Short Bond Fund	1.16%	5.15%	4.44%	4.09%	-2.78%	-0.30%	1.18%	2.95%	2.36%	0.83%
PRTBX Permanent Portfolio Short-Term Treasury Portfolio	0.76%	4.19%	4.12%	3.79%	-2.28%	-0.74%	0.10%	1.76%	1.16%	0.12%

Correlation

The correlation between MWUSX and PRTBX is 0.44, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.44
Correlation (3Y) Calculated over the trailing 3-year period	0.56
Correlation (5Y) Calculated over the trailing 5-year period	0.59
Correlation (10Y) Calculated over the trailing 10-year period	0.45
Correlation (All Time) Calculated using the full available price history since Jul 1, 2003	0.19

Over the past year, MWUSX and PRTBX have become more correlated (0.44) than their long-term average of 0.19, meaning their price movements have been converging.

Return for Risk

MWUSX vs. PRTBX — Risk / Return Rank

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

MWUSX

MWUSX Risk / Return Rank: 86
MWUSX Sharpe Ratio Rank: 57
MWUSX Sortino Ratio Rank: 85
MWUSX Omega Ratio Rank: 97
MWUSX Calmar Ratio Rank: 96
MWUSX Martin Ratio Rank: 97

PRTBX

PRTBX Risk / Return Rank: 99
PRTBX Sharpe Ratio Rank: 99
PRTBX Sortino Ratio Rank: 99
PRTBX Omega Ratio Rank: 98
PRTBX Calmar Ratio Rank: 99
PRTBX Martin Ratio Rank: 99

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.

MWUSX vs. PRTBX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Metropolitan West Ultra Short Bond Fund (MWUSX) and Permanent Portfolio Short-Term Treasury Portfolio (PRTBX). 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.

	MWUSX	PRTBX	Difference
Sharpe ratio: Return per unit of total volatility	2.21	4.73	-2.51
Sortino ratio: Return per unit of downside risk	4.08	8.82	-4.74
Omega ratio: Gain probability vs. loss probability	1.91	2.27	-0.36
Calmar ratio: Return relative to maximum drawdown	6.21	10.02	-3.80
Martin ratio: Return relative to average drawdown	29.29	48.61	-19.32
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

MWUSX vs. PRTBX - Sharpe Ratio Comparison

The current MWUSX Sharpe Ratio is 2.21, which is lower than the PRTBX Sharpe Ratio of 4.73. The chart below compares the historical Sharpe Ratios of MWUSX and PRTBX, 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

	MWUSX	PRTBX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.21	4.73	-2.51
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.95	1.65	-0.70
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	1.02	1.46	-0.44
Sharpe Ratio (All Time) Calculated using the full available price history	0.82	3.89	-3.07

Drawdowns

MWUSX vs. PRTBX - Drawdown Comparison

The maximum MWUSX drawdown since its inception was -25.25%, which is greater than PRTBX's maximum drawdown of -5.13%. Use the drawdown chart below to compare losses from any high point for MWUSX and PRTBX.

Drawdown Indicators

	MWUSX	PRTBX	Difference
Max Drawdown Largest peak-to-trough decline	-25.25%	-5.13%	-20.12%
Max Drawdown (1Y) Largest decline over 1 year	-0.72%	-0.32%	-0.40%
Max Drawdown (3Y) Largest decline over 3 years	-1.10%	-0.44%	-0.66%
Max Drawdown (5Y) Largest decline over 5 years	-5.06%	-3.70%	-1.36%
Max Drawdown (10Y) Largest decline over 10 years	-5.06%	-4.36%	-0.70%
Current Drawdown Current decline from peak	0.00%	-0.02%	+0.02%
Average Drawdown Average peak-to-trough decline	-1.76%	-0.96%	-0.80%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.15%	0.07%	+0.08%

Volatility

MWUSX vs. PRTBX - Volatility Comparison

Metropolitan West Ultra Short Bond Fund (MWUSX) has a higher volatility of 0.47% compared to Permanent Portfolio Short-Term Treasury Portfolio (PRTBX) at 0.15%. This indicates that MWUSX's price experiences larger fluctuations and is considered to be riskier than PRTBX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	MWUSX	PRTBX	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.47%	0.15%	+0.32%
Volatility (6M) Calculated over the trailing 6-month period	1.43%	0.40%	+1.03%
Volatility (1Y) Calculated over the trailing 1-year period	2.01%	0.68%	+1.33%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	2.47%	1.21%	+1.26%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	1.91%	0.86%	+1.05%

MWUSX vs. PRTBX - Expense Ratio Comparison

MWUSX has a 0.50% expense ratio, which is lower than PRTBX's 0.65% expense ratio.

Dividends

MWUSX vs. PRTBX - Dividend Comparison

MWUSX's dividend yield for the trailing twelve months is around 3.85%, more than PRTBX's 3.36% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
MWUSX Metropolitan West Ultra Short Bond Fund	3.85%	3.80%	3.59%	3.25%	1.28%	0.41%	0.93%	2.67%	2.56%	1.06%	1.18%	0.65%
PRTBX Permanent Portfolio Short-Term Treasury Portfolio	3.36%	3.39%	2.69%	1.79%	0.00%	0.00%	0.21%	1.65%	0.83%	0.00%	0.00%	0.00%

Frequently Asked Questions

Can I hold both MWUSX and PRTBX in my portfolio?

MWUSX and PRTBX have a correlation of 0.44, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, MWUSX or PRTBX?

MWUSX has higher volatility (0.47%) compared to PRTBX (0.15%). In terms of maximum drawdown, MWUSX dropped -25.25% vs PRTBX's -5.13%.

Which has better risk-adjusted returns?

PRTBX currently has the higher Sharpe Ratio (4.72 vs 2.21), 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.