NKX vs. RFMZ

Last updated Jun 4, 2026

NKX (Nuveen California AMT-Free Quality Municipal Income Fund) and RFMZ (RiverNorth Flexible Municipal Income Fund II Inc.) are both Municipal Bonds funds. Over the past 5 years, NKX returned 0.82%/yr vs -1.36%/yr for RFMZ. At a 0.37 correlation, their price movements are largely independent. NKX charges 0.04%/yr vs 3.27%/yr for RFMZ.

Performance

NKX vs. RFMZ - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Nuveen California AMT-Free Quality Municipal Income Fund (NKX) and RiverNorth Flexible Municipal Income Fund II Inc. (RFMZ). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, NKX achieves a 4.20% return, which is significantly lower than RFMZ's 7.11% return.

NKX

• 1D: -0.32%
• 1M: 2.23%
• YTD: 4.20%
• 6M: 2.03%
• 1Y: 15.60%
• 3Y*: 11.21%
• 5Y*: 0.82%
• 10Y*: 2.60%

RFMZ

• 1D: -0.75%
• 1M: 2.24%
• YTD: 7.11%
• 6M: 6.46%
• 1Y: 11.90%
• 3Y*: 7.34%
• 5Y*: -1.36%
• 10Y*: —

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

NKX vs. RFMZ - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021
NKX Nuveen California AMT-Free Quality Municipal Income Fund	4.20%	5.99%	16.48%	-1.91%	-18.45%	8.30%
RFMZ RiverNorth Flexible Municipal Income Fund II Inc.	7.11%	2.22%	10.11%	4.54%	-26.41%	3.62%

Correlation

The correlation between NKX and RFMZ 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	0.41
Correlation (5Y) Calculated over the trailing 5-year period	0.37
Correlation (All Time) Calculated using the full available price history since Feb 25, 2021	0.37

Return for Risk

NKX vs. RFMZ — Risk / Return Rank

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

NKX

NKX Risk / Return Rank: 31
NKX Sharpe Ratio Rank: 37
NKX Sortino Ratio Rank: 33
NKX Omega Ratio Rank: 42
NKX Calmar Ratio Rank: 19
NKX Martin Ratio Rank: 22

RFMZ

RFMZ Risk / Return Rank: 27
RFMZ Sharpe Ratio Rank: 24
RFMZ Sortino Ratio Rank: 26
RFMZ Omega Ratio Rank: 24
RFMZ Calmar Ratio Rank: 28
RFMZ Martin Ratio Rank: 32

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.

NKX vs. RFMZ - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Nuveen California AMT-Free Quality Municipal Income Fund (NKX) and RiverNorth Flexible Municipal Income Fund II Inc. (RFMZ). 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.

	NKX	RFMZ	Difference
Sharpe ratio: Return per unit of total volatility	1.76	1.40	+0.36
Sortino ratio: Return per unit of downside risk	2.40	2.15	+0.26
Omega ratio: Gain probability vs. loss probability	1.35	1.26	+0.09
Calmar ratio: Return relative to maximum drawdown	1.61	1.99	-0.38
Martin ratio: Return relative to average drawdown	5.70	7.27	-1.58
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

NKX vs. RFMZ - Sharpe Ratio Comparison

The current NKX Sharpe Ratio is 1.76, which is comparable to the RFMZ Sharpe Ratio of 1.40. The chart below compares the historical Sharpe Ratios of NKX and RFMZ, 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

	NKX	RFMZ	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.76	1.40	+0.36
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.07	-0.10	+0.17
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.20	—	—
Sharpe Ratio (All Time) Calculated using the full available price history	0.34	-0.06	+0.39

Drawdowns

NKX vs. RFMZ - Drawdown Comparison

The maximum NKX drawdown since its inception was -43.89%, which is greater than RFMZ's maximum drawdown of -39.28%. Use the drawdown chart below to compare losses from any high point for NKX and RFMZ.

Drawdown Indicators

	NKX	RFMZ	Difference
Max Drawdown Largest peak-to-trough decline	-43.89%	-39.28%	-4.61%
Max Drawdown (1Y) Largest decline over 1 year	-9.74%	-6.02%	-3.72%
Max Drawdown (3Y) Largest decline over 3 years	-14.53%	-19.98%	+5.45%
Max Drawdown (5Y) Largest decline over 5 years	-35.64%	-39.28%	+3.64%
Max Drawdown (10Y) Largest decline over 10 years	-35.64%	—	—
Current Drawdown Current decline from peak	-2.00%	-14.06%	+12.06%
Average Drawdown Average peak-to-trough decline	-8.35%	-20.26%	+11.91%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.75%	1.64%	+1.11%

Volatility

NKX vs. RFMZ - Volatility Comparison

The current volatility for Nuveen California AMT-Free Quality Municipal Income Fund (NKX) is 2.33%, while RiverNorth Flexible Municipal Income Fund II Inc. (RFMZ) has a volatility of 3.23%. This indicates that NKX experiences smaller price fluctuations and is considered to be less risky than RFMZ based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	NKX	RFMZ	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.33%	3.23%	-0.90%
Volatility (6M) Calculated over the trailing 6-month period	7.00%	6.28%	+0.72%
Volatility (1Y) Calculated over the trailing 1-year period	8.91%	8.52%	+0.39%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	12.34%	13.70%	-1.36%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	12.84%	13.41%	-0.57%

NKX vs. RFMZ - Expense Ratio Comparison

NKX has a 0.04% expense ratio, which is lower than RFMZ's 3.27% expense ratio.

Dividends

NKX vs. RFMZ - Dividend Comparison

NKX's dividend yield for the trailing twelve months is around 7.25%, less than RFMZ's 7.62% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
NKX Nuveen California AMT-Free Quality Municipal Income Fund	7.25%	7.33%	6.14%	4.38%	5.17%	4.21%	4.05%	4.06%	5.25%	5.06%	6.18%	5.66%
RFMZ RiverNorth Flexible Municipal Income Fund II Inc.	7.62%	8.13%	7.76%	7.92%	8.53%	4.53%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%

Frequently Asked Questions

Can I hold both NKX and RFMZ in my portfolio?

NKX and RFMZ 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, NKX or RFMZ?

RFMZ has higher volatility (3.23%) compared to NKX (2.33%). In terms of maximum drawdown, NKX dropped -43.89% vs RFMZ's -39.28%.

Which has better risk-adjusted returns?

NKX currently has the higher Sharpe Ratio (1.76 vs 1.40), 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.