NUMI vs. MFLX

Last updated Jun 4, 2026

NUMI (Nuveen Municipal Income ETF) and MFLX (First Trust Flexible Municipal High Income ETF) are both Municipal Bonds funds. Both are actively managed. Over the past year, NUMI returned 7.75% vs 9.22% for MFLX. A 0.53 correlation means they provide meaningful diversification when combined. NUMI charges 0.29%/yr vs 0.88%/yr for MFLX.

Performance

NUMI vs. MFLX - Performance Comparison

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

Returns By Period

In the year-to-date period, NUMI achieves a 1.53% return, which is significantly lower than MFLX's 3.33% return.

NUMI

• 1D: 0.06%
• 1M: 0.54%
• YTD: 1.53%
• 6M: 1.91%
• 1Y: 7.75%
• 3Y*: —
• 5Y*: —
• 10Y*: —

MFLX

• 1D: -0.06%
• 1M: 1.21%
• YTD: 3.33%
• 6M: 3.84%
• 1Y: 9.22%
• 3Y*: 5.48%
• 5Y*: -0.03%
• 10Y*: —

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

NUMI vs. MFLX - Yearly Performance Comparison

	2026 (YTD)	2025
NUMI Nuveen Municipal Income ETF	1.53%	3.84%
MFLX First Trust Flexible Municipal High Income ETF	3.33%	4.47%

Correlation

The correlation between NUMI and MFLX is 0.55, 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	0.55
Correlation (All Time) Calculated using the full available price history since Jan 24, 2025	0.53

The correlation between NUMI and MFLX has been stable across timeframes, ranging from 0.53 to 0.55 - a consistent structural relationship.

Return for Risk

NUMI vs. MFLX — Risk / Return Rank

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

NUMI

NUMI Risk / Return Rank: 66
NUMI Sharpe Ratio Rank: 69
NUMI Sortino Ratio Rank: 74
NUMI Omega Ratio Rank: 81
NUMI Calmar Ratio Rank: 56
NUMI Martin Ratio Rank: 51

MFLX

MFLX Risk / Return Rank: 71
MFLX Sharpe Ratio Rank: 69
MFLX Sortino Ratio Rank: 78
MFLX Omega Ratio Rank: 82
MFLX Calmar Ratio Rank: 60
MFLX Martin Ratio Rank: 66

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.

NUMI vs. MFLX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Nuveen Municipal Income ETF (NUMI) and First Trust Flexible Municipal High Income ETF (MFLX). 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.

	NUMI	MFLX	Difference
Sharpe ratio: Return per unit of total volatility	2.24	2.27	-0.03
Sortino ratio: Return per unit of downside risk	3.32	3.47	-0.15
Omega ratio: Gain probability vs. loss probability	1.48	1.49	-0.01
Calmar ratio: Return relative to maximum drawdown	2.76	2.97	-0.22
Martin ratio: Return relative to average drawdown	8.62	11.95	-3.33
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

NUMI vs. MFLX - Sharpe Ratio Comparison

The current NUMI Sharpe Ratio is 2.24, which is comparable to the MFLX Sharpe Ratio of 2.27. The chart below compares the historical Sharpe Ratios of NUMI and MFLX, 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

	NUMI	MFLX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.24	2.27	-0.03
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	—	-0.00	—
Sharpe Ratio (All Time) Calculated using the full available price history	0.91	0.19	+0.72

Drawdowns

NUMI vs. MFLX - Drawdown Comparison

The maximum NUMI drawdown since its inception was -4.72%, smaller than the maximum MFLX drawdown of -26.76%. Use the drawdown chart below to compare losses from any high point for NUMI and MFLX.

Drawdown Indicators

	NUMI	MFLX	Difference
Max Drawdown Largest peak-to-trough decline	-4.72%	-26.76%	+22.04%
Max Drawdown (1Y) Largest decline over 1 year	-2.82%	-3.11%	+0.29%
Max Drawdown (3Y) Largest decline over 3 years	—	-8.18%	—
Max Drawdown (5Y) Largest decline over 5 years	—	-25.88%	—
Current Drawdown Current decline from peak	-0.63%	-3.78%	+3.15%
Average Drawdown Average peak-to-trough decline	-1.39%	-8.17%	+6.78%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.90%	0.77%	+0.13%

Volatility

NUMI vs. MFLX - Volatility Comparison

The current volatility for Nuveen Municipal Income ETF (NUMI) is 1.05%, while First Trust Flexible Municipal High Income ETF (MFLX) has a volatility of 1.41%. This indicates that NUMI experiences smaller price fluctuations and is considered to be less risky than MFLX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	NUMI	MFLX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.05%	1.41%	-0.36%
Volatility (6M) Calculated over the trailing 6-month period	2.23%	2.98%	-0.75%
Volatility (1Y) Calculated over the trailing 1-year period	3.48%	4.08%	-0.60%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	4.39%	10.36%	-5.97%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	4.39%	11.29%	-6.90%

NUMI vs. MFLX - Expense Ratio Comparison

NUMI has a 0.29% expense ratio, which is lower than MFLX's 0.88% expense ratio.

Dividends

NUMI vs. MFLX - Dividend Comparison

NUMI's dividend yield for the trailing twelve months is around 3.66%, less than MFLX's 4.08% 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%
NUMI Nuveen Municipal Income ETF	3.66%	3.44%	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 NUMI and MFLX in my portfolio?

NUMI and MFLX have a correlation of 0.55, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, NUMI or MFLX?

MFLX has higher volatility (1.41%) compared to NUMI (1.05%). In terms of maximum drawdown, NUMI dropped -4.72% vs MFLX's -26.76%.

Which ETF is better, NUMI or MFLX?

On 1-year performance, MFLX leads with 9.22% vs 7.75% for NUMI. On fees, NUMI is cheaper at 0.29% per year. On volatility, NUMI has been the lower-risk option at 1.05%. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, NUMI or MFLX?

Over the 1-year period, MFLX has performed better with a 9.22% return vs 7.75%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, NUMI or MFLX?

NUMI is cheaper with a 0.29% expense ratio, compared with 0.88% for MFLX.

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

MFLX has the higher dividend yield at 4.08%, compared with 3.66% for NUMI.

What is the main difference between NUMI and MFLX?

They also come from different issuers: Nuveen and First Trust. Their fees differ too: 0.29% for NUMI and 0.88% for MFLX.

Which has better risk-adjusted returns?

MFLX currently has the higher Sharpe Ratio (2.27 vs 2.24), 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.