AMUN vs. MUB

Last updated Apr 2, 2026

Compare and contrast key facts about abrdn Ultra Short Municipal Income Active ETF (AMUN) and iShares National AMT-Free Muni Bond ETF (MUB).

AMUN and MUB are both exchange-traded funds (ETFs), meaning they are traded on stock exchanges and can be bought and sold throughout the day. AMUN is an actively managed fund by abrdn. It was launched on Oct 20, 2025. MUB is a passively managed fund by iShares that tracks the performance of the S&P National AMT-Free Municipal Bond Index. It was launched on Sep 7, 2007.

Performance

AMUN vs. MUB - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in abrdn Ultra Short Municipal Income Active ETF (AMUN) and iShares National AMT-Free Muni Bond ETF (MUB). The values are adjusted to include any dividend payments, if applicable.

AMUN vs. MUB - Yearly Performance Comparison

	2026 (YTD)	2025
AMUN abrdn Ultra Short Municipal Income Active ETF	0.56%	0.14%
MUB iShares National AMT-Free Muni Bond ETF	0.04%	0.42%

Returns By Period

In the year-to-date period, AMUN achieves a 0.56% return, which is significantly higher than MUB's 0.04% return.

AMUN

• 1D: 0.03%
• 1M: 0.10%
• YTD: 0.56%
• 6M: —
• 1Y: —
• 3Y*: —
• 5Y*: —
• 10Y*: —

MUB

• 1D: 0.42%
• 1M: -1.55%
• YTD: 0.04%
• 6M: 1.52%
• 1Y: 4.03%
• 3Y*: 2.67%
• 5Y*: 0.88%
• 10Y*: 2.00%

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

AMUN vs. MUB - Expense Ratio Comparison

AMUN has a 0.25% expense ratio, which is higher than MUB'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%.

AMUN

abrdn Ultra Short Municipal Income Active ETF

MUB

iShares National AMT-Free Muni Bond ETF

Return for Risk

AMUN vs. MUB — Risk / Return Rank

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

MUB

MUB Risk / Return Rank: 49
MUB Sharpe Ratio Rank: 52
MUB Sortino Ratio Rank: 44
MUB Omega Ratio Rank: 55
MUB Calmar Ratio Rank: 49
MUB Martin Ratio Rank: 43

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.

AMUN vs. MUB - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for abrdn Ultra Short Municipal Income Active ETF (AMUN) and iShares National AMT-Free Muni Bond ETF (MUB). 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.

Risk / return metrics aren't available yet — we need at least 12 months of trading data to calculate them.

Sharpe Ratios by Period

	AMUN	MUB	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	—	0.98	—
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	—	0.22	—
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	—	0.41	—
Sharpe Ratio (All Time) Calculated using the full available price history	1.43	0.58	+0.86

Correlation

The correlation between AMUN and MUB is 0.34, which is considered to be low. This implies their price changes are not closely related. A low correlation is generally favorable for portfolio diversification, as it helps to reduce overall risk by spreading it across multiple assets with different performance patterns.

Dividends

AMUN vs. MUB - Dividend Comparison

AMUN's dividend yield for the trailing twelve months is around 1.39%, less than MUB's 3.19% yield.

	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
AMUN abrdn Ultra Short Municipal Income Active ETF	1.39%	0.66%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%
MUB iShares National AMT-Free Muni Bond ETF	3.19%	3.14%	3.01%	2.65%	2.11%	1.81%	2.11%	2.42%	2.46%	2.26%	2.21%	2.51%

Drawdowns

AMUN vs. MUB - Drawdown Comparison

The maximum AMUN drawdown since its inception was -0.61%, smaller than the maximum MUB drawdown of -13.68%. Use the drawdown chart below to compare losses from any high point for AMUN and MUB.

Drawdown Indicators

	AMUN	MUB	Difference
Max Drawdown Largest peak-to-trough decline	-0.61%	-13.68%	+13.07%
Max Drawdown (1Y) Largest decline over 1 year	—	-3.30%	—
Max Drawdown (5Y) Largest decline over 5 years	—	-11.88%	—
Max Drawdown (10Y) Largest decline over 10 years	—	-13.68%	—
Current Drawdown Current decline from peak	-0.02%	-1.87%	+1.85%
Average Drawdown Average peak-to-trough decline	-0.11%	-2.24%	+2.13%
Ulcer Index Depth and duration of drawdowns from previous peaks	—	1.04%	—

Volatility

Volatility by Period

	AMUN	MUB	Difference
Volatility (1M) Calculated over the trailing 1-month period	—	1.56%	—
Volatility (6M) Calculated over the trailing 6-month period	—	2.07%	—
Volatility (1Y) Calculated over the trailing 1-year period	1.11%	4.15%	-3.04%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	1.11%	4.04%	-2.93%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	1.11%	4.91%	-3.80%