OKMUX vs. NMI

Last updated Jun 4, 2026

OKMUX (Oklahoma Municipal Fund) and NMI (Nuveen Municipal Income Fund, Inc.) are both Municipal Bonds funds. Over the past 10 years, OKMUX returned 1.12%/yr vs 2.55%/yr for NMI. At a 0.15 correlation, their price movements are largely independent. OKMUX charges 0.98%/yr vs 0.72%/yr for NMI.

Performance

OKMUX vs. NMI - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Oklahoma Municipal Fund (OKMUX) and Nuveen Municipal Income Fund, Inc. (NMI). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, OKMUX achieves a 1.43% return, which is significantly lower than NMI's 11.65% return. Over the past 10 years, OKMUX has underperformed NMI with an annualized return of 1.12%, while NMI has yielded a comparatively higher 2.55% annualized return.

OKMUX

• 1D: 0.19%
• 1M: 0.46%
• YTD: 1.43%
• 6M: 1.81%
• 1Y: 7.45%
• 3Y*: 3.12%
• 5Y*: -0.04%
• 10Y*: 1.12%

NMI

• 1D: 1.25%
• 1M: 11.12%
• YTD: 11.65%
• 6M: 11.63%
• 1Y: 16.67%
• 3Y*: 8.46%
• 5Y*: 2.69%
• 10Y*: 2.55%

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

OKMUX vs. NMI - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
OKMUX Oklahoma Municipal Fund	1.43%	4.78%	-0.51%	4.94%	-10.69%	0.90%	3.74%	6.00%	0.53%	3.93%
NMI Nuveen Municipal Income Fund, Inc.	11.65%	10.52%	7.03%	1.90%	-15.09%	3.86%	4.70%	16.02%	-8.07%	7.49%

Correlation

The correlation between OKMUX and NMI is 0.19, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.19
Correlation (3Y) Calculated over the trailing 3-year period	0.29
Correlation (5Y) Calculated over the trailing 5-year period	0.28
Correlation (10Y) Calculated over the trailing 10-year period	0.23
Correlation (All Time) Calculated using the full available price history since Sep 26, 1996	0.15

The correlation between OKMUX and NMI shifts across timeframes, from 0.15 (all time) to 0.29 (3 years), reflecting how their relationship changes across market environments.

Return for Risk

OKMUX vs. NMI — Risk / Return Rank

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

OKMUX

OKMUX Risk / Return Rank: 74
OKMUX Sharpe Ratio Rank: 88
OKMUX Sortino Ratio Rank: 92
OKMUX Omega Ratio Rank: 97
OKMUX Calmar Ratio Rank: 46
OKMUX Martin Ratio Rank: 47

NMI

NMI Risk / Return Rank: 18
NMI Sharpe Ratio Rank: 14
NMI Sortino Ratio Rank: 17
NMI Omega Ratio Rank: 27
NMI Calmar Ratio Rank: 18
NMI Martin Ratio Rank: 12

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.

OKMUX vs. NMI - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Oklahoma Municipal Fund (OKMUX) and Nuveen Municipal Income Fund, Inc. (NMI). 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.

	OKMUX	NMI	Difference
Sharpe ratio Return per unit of total volatility	2.90	1.05	+1.84
Sortino ratio Return per unit of downside risk	4.62	1.72	+2.90
Omega ratio Gain probability vs. loss probability	1.94	1.27	+0.67
Calmar ratio Return relative to maximum drawdown	2.59	1.53	+1.07
Martin ratio Return relative to average drawdown	9.77	3.59	+6.18
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

OKMUX vs. NMI - Sharpe Ratio Comparison

The current OKMUX Sharpe Ratio is 2.90, which is higher than the NMI Sharpe Ratio of 1.05. The chart below compares the historical Sharpe Ratios of OKMUX and NMI, 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

	OKMUX	NMI	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.90	1.05	+1.84
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	-0.01	0.19	-0.20
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.27	0.17	+0.10
Sharpe Ratio (All Time) Calculated using the full available price history	0.62	0.34	+0.28

Drawdowns

OKMUX vs. NMI - Drawdown Comparison

The maximum OKMUX drawdown since its inception was -16.68%, smaller than the maximum NMI drawdown of -28.92%. Use the drawdown chart below to compare losses from any high point for OKMUX and NMI.

Drawdown Indicators

	OKMUX	NMI	Difference
Max Drawdown Largest peak-to-trough decline	-16.68%	-28.92%	+12.24%
Max Drawdown (1Y) Largest decline over 1 year	-2.88%	-10.96%	+8.08%
Max Drawdown (3Y) Largest decline over 3 years	-6.81%	-14.54%	+7.73%
Max Drawdown (5Y) Largest decline over 5 years	-15.39%	-28.92%	+13.53%
Max Drawdown (10Y) Largest decline over 10 years	-15.39%	-28.92%	+13.53%
Current Drawdown Current decline from peak	-1.31%	-1.06%	-0.25%
Average Drawdown Average peak-to-trough decline	-2.52%	-5.92%	+3.40%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.76%	4.65%	-3.89%

Volatility

OKMUX vs. NMI - Volatility Comparison

The current volatility for Oklahoma Municipal Fund (OKMUX) is 0.96%, while Nuveen Municipal Income Fund, Inc. (NMI) has a volatility of 7.35%. This indicates that OKMUX experiences smaller price fluctuations and is considered to be less risky than NMI based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	OKMUX	NMI	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.96%	7.35%	-6.39%
Volatility (6M) Calculated over the trailing 6-month period	1.96%	13.32%	-11.36%
Volatility (1Y) Calculated over the trailing 1-year period	2.58%	15.90%	-13.32%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	4.49%	14.46%	-9.97%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	4.15%	14.93%	-10.78%

OKMUX vs. NMI - Expense Ratio Comparison

OKMUX has a 0.98% expense ratio, which is higher than NMI's 0.72% expense ratio.

Dividends

OKMUX vs. NMI - Dividend Comparison

OKMUX's dividend yield for the trailing twelve months is around 3.20%, less than NMI's 4.19% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
NMI Nuveen Municipal Income Fund, Inc.	4.19%	4.59%	4.63%	4.04%	3.51%	3.22%	3.53%	4.15%	5.12%	4.21%	4.45%	4.28%
OKMUX Oklahoma Municipal Fund	3.20%	3.18%	3.01%	2.32%	1.85%	1.39%	1.73%	2.55%	2.41%	2.47%	2.43%	2.22%

Frequently Asked Questions

Can I hold both OKMUX and NMI in my portfolio?

OKMUX and NMI have a correlation of 0.19, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, OKMUX or NMI?

NMI has higher volatility (7.35%) compared to OKMUX (0.96%). In terms of maximum drawdown, OKMUX dropped -16.68% vs NMI's -28.92%.

Which has better risk-adjusted returns?

OKMUX currently has the higher Sharpe Ratio (2.90 vs 1.05), 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.