OBIIX vs. WISIX

Last updated Jun 4, 2026

OBIIX (Oberweis International Opportunities Institutional Fund) and WISIX (William Blair International Small Cap Growth Fund) are both Foreign Small & Mid Cap Equities funds. Over the past 10 years, OBIIX returned 7.38%/yr vs 6.04%/yr for WISIX. Their correlation of 0.87 suggests significant overlap in exposure. OBIIX charges 1.10%/yr vs 1.23%/yr for WISIX.

Performance

OBIIX vs. WISIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Oberweis International Opportunities Institutional Fund (OBIIX) and William Blair International Small Cap Growth Fund (WISIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, OBIIX achieves a 9.74% return, which is significantly lower than WISIX's 12.59% return. Over the past 10 years, OBIIX has outperformed WISIX with an annualized return of 7.38%, while WISIX has yielded a comparatively lower 6.04% annualized return.

OBIIX

• 1D: 0.08%
• 1M: 2.77%
• YTD: 9.74%
• 6M: 11.72%
• 1Y: 19.46%
• 3Y*: 16.03%
• 5Y*: -0.97%
• 10Y*: 7.38%

WISIX

• 1D: -0.31%
• 1M: 1.67%
• YTD: 12.59%
• 6M: 15.43%
• 1Y: 13.37%
• 3Y*: 10.92%
• 5Y*: 0.64%
• 10Y*: 6.04%

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

OBIIX vs. WISIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
OBIIX Oberweis International Opportunities Institutional Fund	9.74%	31.07%	4.35%	5.72%	-37.45%	1.92%	63.66%	23.51%	-23.84%	41.06%
WISIX William Blair International Small Cap Growth Fund	12.59%	15.31%	0.80%	14.72%	-34.99%	11.01%	29.09%	34.22%	-24.27%	32.71%

Correlation

The correlation between OBIIX and WISIX is 0.84, 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	0.84
Correlation (3Y) Calculated over the trailing 3-year period	0.85
Correlation (5Y) Calculated over the trailing 5-year period	0.88
Correlation (10Y) Calculated over the trailing 10-year period	0.87
Correlation (All Time) Calculated using the full available price history since Mar 12, 2014	0.87

The correlation between OBIIX and WISIX has been stable across timeframes, ranging from 0.84 to 0.88 - a consistent structural relationship.

Return for Risk

OBIIX vs. WISIX — Risk / Return Rank

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

OBIIX

OBIIX Risk / Return Rank: 15
OBIIX Sharpe Ratio Rank: 15
OBIIX Sortino Ratio Rank: 15
OBIIX Omega Ratio Rank: 15
OBIIX Calmar Ratio Rank: 12
OBIIX Martin Ratio Rank: 15

WISIX

WISIX Risk / Return Rank: 12
WISIX Sharpe Ratio Rank: 12
WISIX Sortino Ratio Rank: 12
WISIX Omega Ratio Rank: 13
WISIX Calmar Ratio Rank: 14
WISIX 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.

OBIIX vs. WISIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Oberweis International Opportunities Institutional Fund (OBIIX) and William Blair International Small Cap Growth Fund (WISIX). 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.

	OBIIX	WISIX	Difference
Sharpe ratio Return per unit of total volatility	1.10	0.93	+0.18
Sortino ratio Return per unit of downside risk	1.62	1.37	+0.24
Omega ratio Gain probability vs. loss probability	1.20	1.18	+0.03
Calmar ratio Return relative to maximum drawdown	1.17	1.26	-0.09
Martin ratio Return relative to average drawdown	4.16	3.49	+0.67
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

OBIIX vs. WISIX - Sharpe Ratio Comparison

The current OBIIX Sharpe Ratio is 1.10, which is comparable to the WISIX Sharpe Ratio of 0.93. The chart below compares the historical Sharpe Ratios of OBIIX and WISIX, 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

	OBIIX	WISIX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.10	0.93	+0.18
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	-0.05	0.04	-0.09
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.38	0.35	+0.03
Sharpe Ratio (All Time) Calculated using the full available price history	0.35	0.35	0.00

Drawdowns

OBIIX vs. WISIX - Drawdown Comparison

The maximum OBIIX drawdown since its inception was -51.22%, smaller than the maximum WISIX drawdown of -64.84%. Use the drawdown chart below to compare losses from any high point for OBIIX and WISIX.

Drawdown Indicators

	OBIIX	WISIX	Difference
Max Drawdown Largest peak-to-trough decline	-51.22%	-64.84%	+13.62%
Max Drawdown (1Y) Largest decline over 1 year	-15.67%	-10.09%	-5.58%
Max Drawdown (3Y) Largest decline over 3 years	-17.08%	-17.90%	+0.82%
Max Drawdown (5Y) Largest decline over 5 years	-51.22%	-47.76%	-3.46%
Max Drawdown (10Y) Largest decline over 10 years	-51.22%	-47.76%	-3.46%
Current Drawdown Current decline from peak	-12.70%	-9.75%	-2.95%
Average Drawdown Average peak-to-trough decline	-17.23%	-16.57%	-0.66%
Ulcer Index Depth and duration of drawdowns from previous peaks	4.40%	3.62%	+0.78%

Volatility

OBIIX vs. WISIX - Volatility Comparison

Oberweis International Opportunities Institutional Fund (OBIIX) has a higher volatility of 5.06% compared to William Blair International Small Cap Growth Fund (WISIX) at 4.53%. This indicates that OBIIX's price experiences larger fluctuations and is considered to be riskier than WISIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	OBIIX	WISIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	5.06%	4.53%	+0.53%
Volatility (6M) Calculated over the trailing 6-month period	14.10%	11.48%	+2.62%
Volatility (1Y) Calculated over the trailing 1-year period	16.70%	13.72%	+2.98%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	19.67%	17.29%	+2.38%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	19.69%	17.36%	+2.33%

OBIIX vs. WISIX - Expense Ratio Comparison

OBIIX has a 1.10% expense ratio, which is lower than WISIX's 1.23% expense ratio.

Dividends

OBIIX vs. WISIX - Dividend Comparison

OBIIX's dividend yield for the trailing twelve months is around 1.00%, more than WISIX's 0.54% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
OBIIX Oberweis International Opportunities Institutional Fund	1.00%	1.10%	0.00%	1.93%	0.00%	31.91%	0.51%	1.31%	13.63%	7.30%	0.40%	0.55%
WISIX William Blair International Small Cap Growth Fund	0.54%	0.61%	1.78%	0.88%	0.21%	16.20%	2.09%	0.31%	13.84%	9.94%	0.36%	2.31%

Frequently Asked Questions

Can I hold both OBIIX and WISIX in my portfolio?

OBIIX and WISIX have a correlation of 0.84, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, OBIIX or WISIX?

OBIIX has higher volatility (5.06%) compared to WISIX (4.53%). In terms of maximum drawdown, OBIIX dropped -51.22% vs WISIX's -64.84%.

Which has better risk-adjusted returns?

OBIIX currently has the higher Sharpe Ratio (1.10 vs 0.93), 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.