RFM vs. NMZ

Last updated Jun 5, 2026

RFM (RiverNorth Flexible Municipal Income Fund) and NMZ (Nuveen Municipal High Income Opportunity Fund) are both High Yield Muni funds. Over the past 5 years, RFM returned -1.67%/yr vs -1.46%/yr for NMZ. At a 0.42 correlation, their price movements are largely independent. RFM charges 5.15%/yr vs 1.50%/yr for NMZ.

Performance

RFM vs. NMZ - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in RiverNorth Flexible Municipal Income Fund (RFM) and Nuveen Municipal High Income Opportunity Fund (NMZ). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, RFM achieves a 7.96% return, which is significantly higher than NMZ's 3.70% return.

RFM

• 1D: -0.01%
• 1M: 2.56%
• YTD: 7.96%
• 6M: 6.99%
• 1Y: 12.10%
• 3Y*: 6.65%
• 5Y*: -1.67%
• 10Y*: —

NMZ

• 1D: 0.39%
• 1M: 1.03%
• YTD: 3.70%
• 6M: 0.41%
• 1Y: 7.19%
• 3Y*: 5.60%
• 5Y*: -1.46%
• 10Y*: 2.67%

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

RFM vs. NMZ - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020
RFM RiverNorth Flexible Municipal Income Fund	7.96%	1.59%	3.24%	6.50%	-22.85%	10.85%	15.33%
NMZ Nuveen Municipal High Income Opportunity Fund	3.70%	1.56%	16.52%	0.69%	-27.36%	10.41%	23.36%

Correlation

The correlation between RFM and NMZ is 0.37, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.37
Correlation (3Y) Calculated over the trailing 3-year period	0.51
Correlation (5Y) Calculated over the trailing 5-year period	0.48
Correlation (All Time) Calculated using the full available price history since Mar 30, 2020	0.42

The correlation between RFM and NMZ shifts across timeframes, from 0.37 (1 year) to 0.51 (3 years), reflecting how their relationship changes across market environments.

Return for Risk

RFM vs. NMZ — Risk / Return Rank

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

RFM

RFM Risk / Return Rank: 26
RFM Sharpe Ratio Rank: 22
RFM Sortino Ratio Rank: 22
RFM Omega Ratio Rank: 23
RFM Calmar Ratio Rank: 33
RFM Martin Ratio Rank: 29

NMZ

NMZ Risk / Return Rank: 11
NMZ Sharpe Ratio Rank: 10
NMZ Sortino Ratio Rank: 11
NMZ Omega Ratio Rank: 10
NMZ Calmar Ratio Rank: 14
NMZ Martin Ratio Rank: 11

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.

RFM vs. NMZ - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for RiverNorth Flexible Municipal Income Fund (RFM) and Nuveen Municipal High Income Opportunity Fund (NMZ). 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.

	RFM	NMZ	Difference
Sharpe ratio: Return per unit of total volatility	1.29	0.77	+0.52
Sortino ratio: Return per unit of downside risk	1.90	1.22	+0.68
Omega ratio: Gain probability vs. loss probability	1.24	1.15	+0.10
Calmar ratio: Return relative to maximum drawdown	2.08	1.22	+0.87
Martin ratio: Return relative to average drawdown	6.52	3.06	+3.46
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

RFM vs. NMZ - Sharpe Ratio Comparison

The current RFM Sharpe Ratio is 1.29, which is higher than the NMZ Sharpe Ratio of 0.77. The chart below compares the historical Sharpe Ratios of RFM and NMZ, 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

	RFM	NMZ	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.29	0.77	+0.52
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	-0.13	-0.11	-0.02
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	—	0.18	—
Sharpe Ratio (All Time) Calculated using the full available price history	0.22	0.27	-0.04

Drawdowns

RFM vs. NMZ - Drawdown Comparison

The maximum RFM drawdown since its inception was -35.49%, smaller than the maximum NMZ drawdown of -58.53%. Use the drawdown chart below to compare losses from any high point for RFM and NMZ.

Drawdown Indicators

	RFM	NMZ	Difference
Max Drawdown Largest peak-to-trough decline	-35.49%	-58.53%	+23.04%
Max Drawdown (1Y) Largest decline over 1 year	-5.83%	-5.94%	+0.11%
Max Drawdown (3Y) Largest decline over 3 years	-19.08%	-21.56%	+2.48%
Max Drawdown (5Y) Largest decline over 5 years	-35.49%	-40.03%	+4.54%
Max Drawdown (10Y) Largest decline over 10 years	—	-40.03%	—
Current Drawdown Current decline from peak	-11.37%	-11.94%	+0.57%
Average Drawdown Average peak-to-trough decline	-14.72%	-9.47%	-5.25%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.86%	2.35%	-0.49%

Volatility

RFM vs. NMZ - Volatility Comparison

RiverNorth Flexible Municipal Income Fund (RFM) has a higher volatility of 3.20% compared to Nuveen Municipal High Income Opportunity Fund (NMZ) at 2.47%. This indicates that RFM's price experiences larger fluctuations and is considered to be riskier than NMZ based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	RFM	NMZ	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.20%	2.47%	+0.73%
Volatility (6M) Calculated over the trailing 6-month period	7.42%	7.29%	+0.13%
Volatility (1Y) Calculated over the trailing 1-year period	9.40%	9.38%	+0.02%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	12.86%	12.93%	-0.07%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	12.71%	14.76%	-2.05%

RFM vs. NMZ - Expense Ratio Comparison

RFM has a 5.15% expense ratio, which is higher than NMZ's 1.50% expense ratio.

Dividends

RFM vs. NMZ - Dividend Comparison

RFM's dividend yield for the trailing twelve months is around 7.51%, less than NMZ's 7.68% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
NMZ Nuveen Municipal High Income Opportunity Fund	7.68%	7.71%	6.35%	5.44%	7.04%	5.10%	5.09%	4.99%	6.15%	5.94%	6.94%	6.67%
RFM RiverNorth Flexible Municipal Income Fund	7.51%	8.07%	7.70%	7.64%	8.38%	10.49%	5.07%	0.00%	0.00%	0.00%	0.00%	0.00%

Frequently Asked Questions

Can I hold both RFM and NMZ in my portfolio?

RFM and NMZ have a correlation of 0.37, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, RFM or NMZ?

RFM has higher volatility (3.20%) compared to NMZ (2.47%). In terms of maximum drawdown, RFM dropped -35.49% vs NMZ's -58.53%.

Which has better risk-adjusted returns?

RFM currently has the higher Sharpe Ratio (1.29 vs 0.77), 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.