VSDM vs. SUB

Last updated Jun 3, 2026

VSDM (Vanguard Short Duration Tax-Exempt Bond ETF) and SUB (iShares Short-Term National Muni Bond ETF) are both Municipal Bonds funds. VSDM is actively managed, while SUB is passively managed. Over the past year, VSDM returned 4.93% vs 3.21% for SUB. A 0.59 correlation means they provide meaningful diversification when combined. VSDM charges 0.12%/yr vs 0.07%/yr for SUB.

Performance

VSDM vs. SUB - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Vanguard Short Duration Tax-Exempt Bond ETF (VSDM) and iShares Short-Term National Muni Bond ETF (SUB). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, VSDM achieves a 1.22% return, which is significantly higher than SUB's 0.78% return.

VSDM

• 1D: 0.10%
• 1M: 0.41%
• YTD: 1.22%
• 6M: 1.62%
• 1Y: 4.93%
• 3Y*: —
• 5Y*: —
• 10Y*: —

SUB

• 1D: 0.07%
• 1M: 0.29%
• YTD: 0.78%
• 6M: 1.19%
• 1Y: 3.21%
• 3Y*: 3.19%
• 5Y*: 1.46%
• 10Y*: 1.49%

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

VSDM vs. SUB - Yearly Performance Comparison

	2026 (YTD)	2025	2024
VSDM Vanguard Short Duration Tax-Exempt Bond ETF	1.22%	5.39%	-0.15%
SUB iShares Short-Term National Muni Bond ETF	0.78%	3.64%	0.28%

Correlation

The correlation between VSDM and SUB is 0.58, 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	0.58
Correlation (All Time) Calculated using the full available price history since Nov 22, 2024	0.59

The correlation between VSDM and SUB has been stable across timeframes, ranging from 0.58 to 0.59 - a consistent structural relationship.

Return for Risk

VSDM vs. SUB — Risk / Return Rank

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

VSDM

VSDM Risk / Return Rank: 84
VSDM Sharpe Ratio Rank: 94
VSDM Sortino Ratio Rank: 95
VSDM Omega Ratio Rank: 97
VSDM Calmar Ratio Rank: 67
VSDM Martin Ratio Rank: 65

SUB

SUB Risk / Return Rank: 84
SUB Sharpe Ratio Rank: 91
SUB Sortino Ratio Rank: 93
SUB Omega Ratio Rank: 95
SUB Calmar Ratio Rank: 77
SUB Martin Ratio Rank: 62

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.

VSDM vs. SUB - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Vanguard Short Duration Tax-Exempt Bond ETF (VSDM) and iShares Short-Term National Muni Bond ETF (SUB). 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.

	VSDM	SUB	Difference
Sharpe ratio Return per unit of total volatility	3.62	3.23	+0.40
Sortino ratio Return per unit of downside risk	5.28	4.68	+0.60
Omega ratio Gain probability vs. loss probability	1.90	1.72	+0.18
Calmar ratio Return relative to maximum drawdown	3.40	3.96	-0.56
Martin ratio Return relative to average drawdown	12.04	11.24	+0.80
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

VSDM vs. SUB - Sharpe Ratio Comparison

The current VSDM Sharpe Ratio is 3.62, which is comparable to the SUB Sharpe Ratio of 3.23. The chart below compares the historical Sharpe Ratios of VSDM and SUB, 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

	VSDM	SUB	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	3.62	3.23	+0.40
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	—	0.89	—
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	—	0.57	—
Sharpe Ratio (All Time) Calculated using the full available price history	2.19	0.42	+1.77

Drawdowns

VSDM vs. SUB - Drawdown Comparison

The maximum VSDM drawdown since its inception was -1.81%, smaller than the maximum SUB drawdown of -9.46%. Use the drawdown chart below to compare losses from any high point for VSDM and SUB.

Drawdown Indicators

	VSDM	SUB	Difference
Max Drawdown Largest peak-to-trough decline	-1.81%	-9.46%	+7.65%
Max Drawdown (1Y) Largest decline over 1 year	-1.46%	-0.81%	-0.65%
Max Drawdown (3Y) Largest decline over 3 years	—	-1.23%	—
Max Drawdown (5Y) Largest decline over 5 years	—	-4.35%	—
Max Drawdown (10Y) Largest decline over 10 years	—	-9.46%	—
Current Drawdown Current decline from peak	-0.33%	-0.12%	-0.21%
Average Drawdown Average peak-to-trough decline	-0.32%	-0.92%	+0.60%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.41%	0.28%	+0.13%

Volatility

VSDM vs. SUB - Volatility Comparison

Vanguard Short Duration Tax-Exempt Bond ETF (VSDM) has a higher volatility of 0.45% compared to iShares Short-Term National Muni Bond ETF (SUB) at 0.28%. This indicates that VSDM's price experiences larger fluctuations and is considered to be riskier than SUB based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	VSDM	SUB	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.45%	0.28%	+0.17%
Volatility (6M) Calculated over the trailing 6-month period	1.07%	0.79%	+0.28%
Volatility (1Y) Calculated over the trailing 1-year period	1.36%	1.00%	+0.36%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	1.96%	1.64%	+0.32%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	1.96%	2.60%	-0.64%

VSDM vs. SUB - Expense Ratio Comparison

VSDM has a 0.12% expense ratio, which is higher than SUB's 0.07% expense ratio. However, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.

Dividends

VSDM vs. SUB - Dividend Comparison

VSDM's dividend yield for the trailing twelve months is around 3.11%, more than SUB's 2.53% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
SUB iShares Short-Term National Muni Bond ETF	2.53%	2.42%	2.10%	1.73%	0.86%	0.72%	1.23%	1.58%	1.32%	0.95%	0.75%	0.77%
VSDM Vanguard Short Duration Tax-Exempt Bond ETF	3.11%	3.06%	0.35%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%

Frequently Asked Questions

Can I hold both VSDM and SUB in my portfolio?

VSDM and SUB have a correlation of 0.58, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, VSDM or SUB?

VSDM has higher volatility (0.45%) compared to SUB (0.28%). In terms of maximum drawdown, VSDM dropped -1.81% vs SUB's -9.46%.

Which ETF is better, VSDM or SUB?

On 1-year performance, VSDM leads with 4.93% vs 3.21% for SUB. On fees, SUB is cheaper at 0.07% per year. On volatility, SUB has been the lower-risk option at 0.28%. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, VSDM or SUB?

Over the 1-year period, VSDM has performed better with a 4.93% return vs 3.21%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, VSDM or SUB?

SUB is cheaper with a 0.07% expense ratio, compared with 0.12% for VSDM.

Which ETF pays a higher dividend yield, VSDM or SUB?

VSDM has the higher dividend yield at 3.11%, compared with 2.53% for SUB.

What is the main difference between VSDM and SUB?

They also come from different issuers: Vanguard and iShares. Their fees differ too: 0.12% for VSDM and 0.07% for SUB.

Which has better risk-adjusted returns?

VSDM currently has the higher Sharpe Ratio (3.62 vs 3.23), 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.