MFLX vs. ZTAX

Last updated Jul 14, 2026

MFLX (First Trust Flexible Municipal High Income ETF) and ZTAX (X-Square Municipal Income Tax Free ETF) are both Municipal Bonds funds. Both are actively managed. Over the past 3 years, MFLX returned 5.59%/yr vs 5.66%/yr for ZTAX. At a correlation of -0.02, they often move in opposite directions. MFLX charges 0.88%/yr vs 1.14%/yr for ZTAX.

Performance

MFLX vs. ZTAX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in First Trust Flexible Municipal High Income ETF (MFLX) and X-Square Municipal Income Tax Free ETF (ZTAX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, MFLX achieves a 4.02% return, which is significantly higher than ZTAX's 2.49% return.

MFLX

• 1D: 0.03%
• 1M: 0.58%
• 6M: 3.36%
• YTD: 4.02%
• 1Y: 9.47%
• 3Y*: 5.59%
• 5Y*: -0.50%
• 10Y*: —

ZTAX

• 1D: 1.41%
• 1M: 2.10%
• 6M: 1.36%
• YTD: 2.49%
• 1Y: 8.55%
• 3Y*: 5.66%
• 5Y*: —
• 10Y*: —

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

MFLX vs. ZTAX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023
MFLX First Trust Flexible Municipal High Income ETF	4.02%	3.94%	3.74%	6.01%
ZTAX X-Square Municipal Income Tax Free ETF	2.49%	-1.02%	7.98%	3.74%

Correlation

The correlation between MFLX and ZTAX is -0.06, 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 (1Y) Calculated over the trailing 1-year period	-0.06
Correlation (3Y) Calculated over the trailing 3-year period	-0.02
Correlation (All Time) Calculated using the full available price history since May 19, 2023	-0.02

Return for Risk

MFLX vs. ZTAX — Risk / Return Rank

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

MFLX

MFLX Risk / Return Rank: 86
MFLX Sharpe Ratio Rank: 89
MFLX Sortino Ratio Rank: 92
MFLX Omega Ratio Rank: 93
MFLX Calmar Ratio Rank: 75
MFLX Martin Ratio Rank: 83

ZTAX

ZTAX Risk / Return Rank: 18
ZTAX Sharpe Ratio Rank: 14
ZTAX Sortino Ratio Rank: 15
ZTAX Omega Ratio Rank: 19
ZTAX Calmar Ratio Rank: 21
ZTAX Martin Ratio Rank: 20

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.

MFLX vs. ZTAX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for First Trust Flexible Municipal High Income ETF (MFLX) and X-Square Municipal Income Tax Free ETF (ZTAX). 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.

	MFLX	ZTAX	Difference
Sharpe ratio: Return per unit of total volatility	2.34	0.26	+2.08
Sortino ratio: Return per unit of downside risk	3.57	0.61	+2.96
Omega ratio: Gain probability vs. loss probability	1.51	1.11	+0.40
Calmar ratio: Return relative to maximum drawdown	3.05	0.76	+2.29
Martin ratio: Return relative to average drawdown	12.98	1.73	+11.25

MFLX vs. ZTAX - Sharpe Ratio Comparison

The current MFLX Sharpe Ratio is 2.34, which is higher than the ZTAX Sharpe Ratio of 0.26. The chart below compares the historical Sharpe Ratios of MFLX and ZTAX, 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

MFLX vs. ZTAX - Drawdown Comparison

The maximum MFLX drawdown since its inception was -26.76%, which is greater than ZTAX's maximum drawdown of -15.33%. Use the drawdown chart below to compare losses from any high point for MFLX and ZTAX.

Drawdown Indicators

	MFLX	ZTAX	Difference
Max Drawdown Largest peak-to-trough decline	-26.76%	-15.33%	-11.43%
Max Drawdown (1Y) Largest decline over 1 year	-3.11%	-11.26%	+8.15%
Max Drawdown (3Y) Largest decline over 3 years	-8.18%	-15.33%	+7.15%
Max Drawdown (5Y) Largest decline over 5 years	-25.88%	—	—
Current Drawdown Current decline from peak	-3.13%	-10.01%	+6.88%
Average Drawdown Average peak-to-trough decline	-8.12%	-6.85%	-1.27%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.73%	4.94%	-4.21%

Volatility

MFLX vs. ZTAX - Volatility Comparison

The current volatility for First Trust Flexible Municipal High Income ETF (MFLX) is 0.92%, while X-Square Municipal Income Tax Free ETF (ZTAX) has a volatility of 17.55%. This indicates that MFLX experiences smaller price fluctuations and is considered to be less risky than ZTAX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	MFLX	ZTAX	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.92%	17.55%	-16.63%
Volatility (6M) Calculated over the trailing 6-month period	3.08%	26.93%	-23.85%
Volatility (1Y) Calculated over the trailing 1-year period	4.07%	32.80%	-28.73%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	10.35%	28.85%	-18.50%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	11.23%	28.85%	-17.62%

MFLX vs. ZTAX - Expense Ratio Comparison

MFLX has a 0.88% expense ratio, which is lower than ZTAX's 1.14% expense ratio.

Dividends

MFLX vs. ZTAX - Dividend Comparison

MFLX's dividend yield for the trailing twelve months is around 4.08%, less than ZTAX's 4.67% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016
MFLX First Trust Flexible Municipal High Income ETF	4.08%	4.06%	3.81%	3.65%	4.27%	3.69%	3.21%	2.94%	3.74%	3.80%	0.98%
ZTAX X-Square Municipal Income Tax Free ETF	4.67%	4.58%	4.55%	2.14%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%

Frequently Asked Questions

Can I hold both MFLX and ZTAX in my portfolio?

MFLX and ZTAX have a correlation of -0.06, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, MFLX or ZTAX?

ZTAX has higher volatility (17.55%) compared to MFLX (0.92%). In terms of maximum drawdown, MFLX dropped -26.76% vs ZTAX's -15.33%.

Which ETF is better, MFLX or ZTAX?

On 3-year performance, ZTAX leads with 5.66% vs 5.59% for MFLX. On fees, MFLX is cheaper at 0.88% per year. On volatility, MFLX has been the lower-risk option at 0.92%. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, MFLX or ZTAX?

Over the 3-year period, ZTAX has performed better with a 5.66% return vs 5.59%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, MFLX or ZTAX?

MFLX is cheaper with a 0.88% expense ratio, compared with 1.14% for ZTAX.

Which ETF pays a higher dividend yield, MFLX or ZTAX?

ZTAX has the higher dividend yield at 4.67%, compared with 4.08% for MFLX.

What is the main difference between MFLX and ZTAX?

They also come from different issuers: First Trust and X-Square. Their fees differ too: 0.88% for MFLX and 1.14% for ZTAX.

Which has better risk-adjusted returns?

MFLX currently has the higher Sharpe Ratio (2.34 vs 0.26), 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.