VNDFX vs. OKMUX

Last updated Jun 3, 2026

VNDFX (Viking Tax-Free Fund for North Dakota) and OKMUX (Oklahoma Municipal Fund) are both Municipal Bonds funds from IntegrityVikingFunds. Over the past 10 years, VNDFX returned 0.67%/yr vs 1.10%/yr for OKMUX. A 0.68 correlation means they provide meaningful diversification when combined. Both charge a 0.98% expense ratio.

Performance

VNDFX vs. OKMUX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Viking Tax-Free Fund for North Dakota (VNDFX) and Oklahoma Municipal Fund (OKMUX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, VNDFX achieves a 1.74% return, which is significantly higher than OKMUX's 1.24% return. Over the past 10 years, VNDFX has underperformed OKMUX with an annualized return of 0.67%, while OKMUX has yielded a comparatively higher 1.10% annualized return.

VNDFX

• 1D: 0.00%
• 1M: 0.36%
• YTD: 1.74%
• 6M: 2.12%
• 1Y: 7.34%
• 3Y*: 2.11%
• 5Y*: -0.62%
• 10Y*: 0.67%

OKMUX

• 1D: 0.00%
• 1M: 0.27%
• YTD: 1.24%
• 6M: 1.62%
• 1Y: 7.25%
• 3Y*: 3.05%
• 5Y*: -0.08%
• 10Y*: 1.10%

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

VNDFX vs. OKMUX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
VNDFX Viking Tax-Free Fund for North Dakota	1.74%	3.02%	-1.96%	4.65%	-9.89%	0.42%	2.90%	5.12%	0.72%	3.35%
OKMUX Oklahoma Municipal Fund	1.24%	4.78%	-0.51%	4.94%	-10.69%	0.90%	3.74%	6.00%	0.53%	3.93%

Correlation

The correlation between VNDFX and OKMUX is 0.86, indicating a strong positive relationship between their price movements. Combining them offers limited diversification - they tend to fall together during downturns.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.86
Correlation (3Y) Calculated over the trailing 3-year period	0.91
Correlation (5Y) Calculated over the trailing 5-year period	0.92
Correlation (10Y) Calculated over the trailing 10-year period	0.89
Correlation (All Time) Calculated using the full available price history since Aug 4, 1999	0.68

The correlation between VNDFX and OKMUX shifts across timeframes, from 0.68 (all time) to 0.92 (5 years), reflecting how their relationship changes across market environments.

Return for Risk

VNDFX vs. OKMUX — Risk / Return Rank

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

VNDFX

VNDFX Risk / Return Rank: 79
VNDFX Sharpe Ratio Rank: 90
VNDFX Sortino Ratio Rank: 93
VNDFX Omega Ratio Rank: 97
VNDFX Calmar Ratio Rank: 57
VNDFX Martin Ratio Rank: 59

OKMUX

OKMUX Risk / Return Rank: 73
OKMUX Sharpe Ratio Rank: 86
OKMUX Sortino Ratio Rank: 90
OKMUX Omega Ratio Rank: 96
OKMUX Calmar Ratio Rank: 45
OKMUX Martin Ratio Rank: 46

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.

VNDFX vs. OKMUX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Viking Tax-Free Fund for North Dakota (VNDFX) and Oklahoma Municipal Fund (OKMUX). 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.

	VNDFX	OKMUX	Difference
Sharpe ratio Return per unit of total volatility	2.97	2.78	+0.19
Sortino ratio Return per unit of downside risk	4.78	4.43	+0.35
Omega ratio Gain probability vs. loss probability	1.94	1.89	+0.06
Calmar ratio Return relative to maximum drawdown	2.92	2.49	+0.43
Martin ratio Return relative to average drawdown	11.94	9.38	+2.57
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

VNDFX vs. OKMUX - Sharpe Ratio Comparison

The current VNDFX Sharpe Ratio is 2.97, which is comparable to the OKMUX Sharpe Ratio of 2.78. The chart below compares the historical Sharpe Ratios of VNDFX and OKMUX, 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

	VNDFX	OKMUX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.97	2.78	+0.19
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	-0.13	-0.02	-0.12
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.17	0.27	-0.10
Sharpe Ratio (All Time) Calculated using the full available price history	0.45	0.62	-0.17

Drawdowns

VNDFX vs. OKMUX - Drawdown Comparison

The maximum VNDFX drawdown since its inception was -14.80%, smaller than the maximum OKMUX drawdown of -16.68%. Use the drawdown chart below to compare losses from any high point for VNDFX and OKMUX.

Drawdown Indicators

	VNDFX	OKMUX	Difference
Max Drawdown Largest peak-to-trough decline	-14.80%	-16.68%	+1.88%
Max Drawdown (1Y) Largest decline over 1 year	-2.57%	-2.88%	+0.31%
Max Drawdown (3Y) Largest decline over 3 years	-8.01%	-6.81%	-1.20%
Max Drawdown (5Y) Largest decline over 5 years	-14.80%	-15.39%	+0.59%
Max Drawdown (10Y) Largest decline over 10 years	-14.80%	-15.39%	+0.59%
Current Drawdown Current decline from peak	-3.56%	-1.49%	-2.07%
Average Drawdown Average peak-to-trough decline	-2.77%	-2.52%	-0.25%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.63%	0.76%	-0.13%

Volatility

VNDFX vs. OKMUX - Volatility Comparison

The current volatility for Viking Tax-Free Fund for North Dakota (VNDFX) is 0.88%, while Oklahoma Municipal Fund (OKMUX) has a volatility of 0.94%. This indicates that VNDFX experiences smaller price fluctuations and is considered to be less risky than OKMUX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	VNDFX	OKMUX	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.88%	0.94%	-0.06%
Volatility (6M) Calculated over the trailing 6-month period	1.83%	1.97%	-0.14%
Volatility (1Y) Calculated over the trailing 1-year period	2.44%	2.58%	-0.14%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	4.61%	4.49%	+0.12%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	4.04%	4.15%	-0.11%

VNDFX vs. OKMUX - Expense Ratio Comparison

Both VNDFX and OKMUX have an expense ratio of 0.98%.

Dividends

VNDFX vs. OKMUX - Dividend Comparison

VNDFX's dividend yield for the trailing twelve months is around 3.01%, less than OKMUX's 3.20% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
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%
VNDFX Viking Tax-Free Fund for North Dakota	3.01%	3.03%	2.93%	2.30%	1.86%	1.69%	2.07%	2.72%	2.58%	2.71%	2.62%	2.38%

Frequently Asked Questions

Can I hold both VNDFX and OKMUX in my portfolio?

VNDFX and OKMUX have a correlation of 0.86, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, VNDFX or OKMUX?

OKMUX has higher volatility (0.94%) compared to VNDFX (0.88%). In terms of maximum drawdown, VNDFX dropped -14.80% vs OKMUX's -16.68%.

Which has better risk-adjusted returns?

VNDFX currently has the higher Sharpe Ratio (2.97 vs 2.78), 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.