MWLDX vs. FUMBX

Last updated Jun 24, 2026

MWLDX (Metropolitan West Low Duration Bond Fund) and FUMBX (Fidelity Short-Term Treasury Bond Index Fund) are both Short-Term Bond funds. Over the past 5 years, MWLDX returned 1.63%/yr vs 1.31%/yr for FUMBX. A 0.77 correlation means they provide meaningful diversification when combined. MWLDX charges 0.62%/yr vs 0.03%/yr for FUMBX.

Performance

MWLDX vs. FUMBX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Metropolitan West Low Duration Bond Fund (MWLDX) and Fidelity Short-Term Treasury Bond Index Fund (FUMBX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, MWLDX achieves a 0.18% return, which is significantly higher than FUMBX's -0.11% return.

MWLDX

• 1D: -0.12%
• 1M: 0.07%
• YTD: 0.18%
• 6M: 0.69%
• 1Y: 3.35%
• 3Y*: 4.29%
• 5Y*: 1.63%
• 10Y*: 1.85%

FUMBX

• 1D: -0.10%
• 1M: 0.16%
• YTD: -0.11%
• 6M: 0.24%
• 1Y: 2.69%
• 3Y*: 4.03%
• 5Y*: 1.31%
• 10Y*: —

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

MWLDX vs. FUMBX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
MWLDX Metropolitan West Low Duration Bond Fund	0.18%	5.72%	3.79%	4.82%	-5.70%	-0.33%	3.27%	4.24%	1.59%	0.07%
FUMBX Fidelity Short-Term Treasury Bond Index Fund	-0.11%	5.83%	3.25%	4.47%	-5.84%	-1.38%	4.22%	4.19%	1.47%	-0.33%

Correlation

The correlation between MWLDX and FUMBX is 0.80, 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	0.80
Correlation (3Y) Calculated over the trailing 3-year period	0.83
Correlation (5Y) Calculated over the trailing 5-year period	0.84
Correlation (All Time) Calculated using the full available price history since Oct 19, 2017	0.77

The correlation between MWLDX and FUMBX has been stable across timeframes, ranging from 0.77 to 0.84 - a consistent structural relationship.

Return for Risk

MWLDX vs. FUMBX — Risk / Return Rank

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

MWLDX

MWLDX Risk / Return Rank: 52
MWLDX Sharpe Ratio Rank: 39
MWLDX Sortino Ratio Rank: 60
MWLDX Omega Ratio Rank: 58
MWLDX Calmar Ratio Rank: 54
MWLDX Martin Ratio Rank: 49

FUMBX

FUMBX Risk / Return Rank: 29
FUMBX Sharpe Ratio Rank: 27
FUMBX Sortino Ratio Rank: 32
FUMBX Omega Ratio Rank: 32
FUMBX Calmar Ratio Rank: 29
FUMBX 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.

MWLDX vs. FUMBX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Metropolitan West Low Duration Bond Fund (MWLDX) and Fidelity Short-Term Treasury Bond Index Fund (FUMBX). 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.

	MWLDX	FUMBX	Difference
Sharpe ratio: Return per unit of total volatility	1.68	1.39	+0.29
Sortino ratio: Return per unit of downside risk	2.98	2.19	+0.79
Omega ratio: Gain probability vs. loss probability	1.39	1.28	+0.11
Calmar ratio: Return relative to maximum drawdown	2.69	1.89	+0.81
Martin ratio: Return relative to average drawdown	9.62	5.55	+4.06

MWLDX vs. FUMBX - Sharpe Ratio Comparison

The current MWLDX Sharpe Ratio is 1.68, which is comparable to the FUMBX Sharpe Ratio of 1.39. The chart below compares the historical Sharpe Ratios of MWLDX and FUMBX, 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

MWLDX vs. FUMBX - Drawdown Comparison

The maximum MWLDX drawdown since its inception was -19.48%, which is greater than FUMBX's maximum drawdown of -8.83%. Use the drawdown chart below to compare losses from any high point for MWLDX and FUMBX.

Drawdown Indicators

	MWLDX	FUMBX	Difference
Max Drawdown Largest peak-to-trough decline	-19.48%	-8.83%	-10.65%
Max Drawdown (1Y) Largest decline over 1 year	-1.29%	-1.54%	+0.25%
Max Drawdown (3Y) Largest decline over 3 years	-1.75%	-1.57%	-0.18%
Max Drawdown (5Y) Largest decline over 5 years	-8.36%	-8.60%	+0.24%
Max Drawdown (10Y) Largest decline over 10 years	-8.36%	—	—
Current Drawdown Current decline from peak	-0.66%	-1.06%	+0.40%
Average Drawdown Average peak-to-trough decline	-1.25%	-1.85%	+0.60%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.36%	0.52%	-0.16%

Volatility

MWLDX vs. FUMBX - Volatility Comparison

The current volatility for Metropolitan West Low Duration Bond Fund (MWLDX) is 0.62%, while Fidelity Short-Term Treasury Bond Index Fund (FUMBX) has a volatility of 0.70%. This indicates that MWLDX experiences smaller price fluctuations and is considered to be less risky than FUMBX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	MWLDX	FUMBX	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.62%	0.70%	-0.08%
Volatility (6M) Calculated over the trailing 6-month period	1.53%	1.56%	-0.03%
Volatility (1Y) Calculated over the trailing 1-year period	2.08%	2.08%	0.00%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	2.87%	2.93%	-0.06%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	2.26%	2.49%	-0.23%

MWLDX vs. FUMBX - Expense Ratio Comparison

MWLDX has a 0.62% expense ratio, which is higher than FUMBX's 0.03% expense ratio.

Dividends

MWLDX vs. FUMBX - Dividend Comparison

MWLDX's dividend yield for the trailing twelve months is around 3.80%, which matches FUMBX's 3.77% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FUMBX Fidelity Short-Term Treasury Bond Index Fund	3.77%	3.51%	2.91%	1.64%	0.86%	1.15%	1.41%	1.88%	1.64%	0.34%	0.00%	0.00%
MWLDX Metropolitan West Low Duration Bond Fund	3.80%	3.75%	3.71%	3.22%	1.56%	0.69%	1.39%	2.41%	2.50%	1.38%	1.52%	1.12%

Frequently Asked Questions

Can I hold both MWLDX and FUMBX in my portfolio?

MWLDX and FUMBX have a correlation of 0.80, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, MWLDX or FUMBX?

FUMBX has higher volatility (0.70%) compared to MWLDX (0.62%). In terms of maximum drawdown, MWLDX dropped -19.48% vs FUMBX's -8.83%.

Which has better risk-adjusted returns?

MWLDX currently has the higher Sharpe Ratio (1.68 vs 1.39), 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.