ZMUN vs. CGSM

Last updated Jun 21, 2026

ZMUN (F/m Ultrashort Tax-Free Municipal ETF) and CGSM (Capital Group Short Duration Municipal Income ETF) are both Municipal Bonds funds. ZMUN is passively managed, while CGSM is actively managed. At a 0.04 correlation, their price movements are largely independent. ZMUN charges 0.30%/yr vs 0.25%/yr for CGSM.

Performance

ZMUN vs. CGSM - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in F/m Ultrashort Tax-Free Municipal ETF (ZMUN) and Capital Group Short Duration Municipal Income ETF (CGSM). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, ZMUN achieves a 1.80% return, which is significantly higher than CGSM's 1.33% return.

ZMUN

• 1D: 0.07%
• 1M: 0.33%
• YTD: 1.80%
• 6M: 1.89%
• 1Y: —
• 3Y*: —
• 5Y*: —
• 10Y*: —

CGSM

• 1D: 0.04%
• 1M: 0.63%
• YTD: 1.33%
• 6M: 1.39%
• 1Y: 4.19%
• 3Y*: —
• 5Y*: —
• 10Y*: —

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

ZMUN vs. CGSM - Yearly Performance Comparison

	2026 (YTD)	2025
ZMUN F/m Ultrashort Tax-Free Municipal ETF	1.80%	0.67%
CGSM Capital Group Short Duration Municipal Income ETF	1.33%	0.80%

Correlation

The correlation between ZMUN and CGSM is 0.04, meaning there is essentially no relationship between their price movements. Each responds to its own set of market drivers, making them strong candidates for combining in a diversified portfolio.

	Correlation
Correlation (All Time) Calculated using the full available price history since Sep 30, 2025	0.04

Return for Risk

ZMUN vs. CGSM — Risk / Return Rank

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

ZMUN

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

CGSM

CGSM Risk / Return Rank: 85
CGSM Sharpe Ratio Rank: 93
CGSM Sortino Ratio Rank: 95
CGSM Omega Ratio Rank: 96
CGSM Calmar Ratio Rank: 75
CGSM Martin Ratio Rank: 67

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.

ZMUN vs. CGSM - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for F/m Ultrashort Tax-Free Municipal ETF (ZMUN) and Capital Group Short Duration Municipal Income ETF (CGSM). 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.

	ZMUN	CGSM	Difference
Sharpe ratio: Return per unit of total volatility	—	3.25	—
Sortino ratio: Return per unit of downside risk	—	4.95	—
Omega ratio: Gain probability vs. loss probability	—	1.73	—
Calmar ratio: Return relative to maximum drawdown	—	3.68	—
Martin ratio: Return relative to average drawdown	—	11.91	—

Drawdowns

ZMUN vs. CGSM - Drawdown Comparison

The maximum ZMUN drawdown since its inception was -0.10%, smaller than the maximum CGSM drawdown of -1.42%. Use the drawdown chart below to compare losses from any high point for ZMUN and CGSM.

Drawdown Indicators

	ZMUN	CGSM	Difference
Max Drawdown Largest peak-to-trough decline	-0.10%	-1.42%	+1.32%
Max Drawdown (1Y) Largest decline over 1 year	—	-1.18%	—
Current Drawdown Current decline from peak	0.00%	-0.18%	+0.18%
Average Drawdown Average peak-to-trough decline	-0.01%	-0.24%	+0.23%
Ulcer Index Depth and duration of drawdowns from previous peaks	—	0.36%	—

Volatility

Volatility by Period

	ZMUN	CGSM	Difference
Volatility (1M) Calculated over the trailing 1-month period	—	0.32%	—
Volatility (6M) Calculated over the trailing 6-month period	—	0.98%	—
Volatility (1Y) Calculated over the trailing 1-year period	0.54%	1.33%	-0.79%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	0.54%	1.78%	-1.24%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	0.54%	1.78%	-1.24%

ZMUN vs. CGSM - Expense Ratio Comparison

ZMUN has a 0.30% expense ratio, which is higher than CGSM's 0.25% expense ratio.

Dividends

ZMUN vs. CGSM - Dividend Comparison

ZMUN's dividend yield for the trailing twelve months is around 2.28%, less than CGSM's 2.99% yield.

Position	TTM	2025	2024	2023
CGSM Capital Group Short Duration Municipal Income ETF	2.99%	3.05%	3.11%	0.84%
ZMUN F/m Ultrashort Tax-Free Municipal ETF	2.28%	0.70%	0.00%	0.00%

Frequently Asked Questions

Can I hold both ZMUN and CGSM in my portfolio?

ZMUN and CGSM have a correlation of 0.04, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which ETF is better, ZMUN or CGSM?

On fees, CGSM is cheaper at 0.25% per year. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF is cheaper, ZMUN or CGSM?

CGSM is cheaper with a 0.25% expense ratio, compared with 0.30% for ZMUN.

Which ETF pays a higher dividend yield, ZMUN or CGSM?

CGSM has the higher dividend yield at 2.99%, compared with 2.28% for ZMUN.

What is the main difference between ZMUN and CGSM?

They also come from different issuers: F/m Investments and Capital Group. Their fees differ too: 0.30% for ZMUN and 0.25% for CGSM.