OBIOX vs. WISIX

Last updated Jun 24, 2026

OBIOX (Oberweis International Opportunities Fund) and WISIX (William Blair International Small Cap Growth Fund) are both Foreign Small & Mid Cap Equities funds. Over the past 10 years, OBIOX returned 7.88%/yr vs 6.79%/yr for WISIX. Their correlation of 0.88 suggests significant overlap in exposure. OBIOX charges 1.60%/yr vs 1.23%/yr for WISIX.

Performance

OBIOX vs. WISIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Oberweis International Opportunities Fund (OBIOX) 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, OBIOX achieves a 11.37% return, which is significantly lower than WISIX's 13.02% return. Over the past 10 years, OBIOX has outperformed WISIX with an annualized return of 7.88%, while WISIX has yielded a comparatively lower 6.79% annualized return.

OBIOX

• 1D: 1.33%
• 1M: 1.29%
• YTD: 11.37%
• 6M: 10.65%
• 1Y: 20.34%
• 3Y*: 17.30%
• 5Y*: -0.14%
• 10Y*: 7.88%

WISIX

• 1D: 0.13%
• 1M: 0.32%
• YTD: 13.02%
• 6M: 13.18%
• 1Y: 14.62%
• 3Y*: 12.00%
• 5Y*: 0.53%
• 10Y*: 6.79%

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

OBIOX vs. WISIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
OBIOX Oberweis International Opportunities Fund	11.37%	30.71%	7.54%	4.90%	-37.06%	1.41%	62.87%	22.87%	-26.57%	40.90%
WISIX William Blair International Small Cap Growth Fund	13.02%	15.31%	0.80%	14.72%	-34.99%	11.01%	29.09%	34.22%	-24.27%	32.71%

Correlation

The correlation between OBIOX 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 Feb 5, 2007	0.88

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

Return for Risk

OBIOX vs. WISIX — Risk / Return Rank

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

OBIOX

OBIOX Risk / Return Rank: 20
OBIOX Sharpe Ratio Rank: 21
OBIOX Sortino Ratio Rank: 21
OBIOX Omega Ratio Rank: 22
OBIOX Calmar Ratio Rank: 17
OBIOX Martin Ratio Rank: 20

WISIX

WISIX Risk / Return Rank: 16
WISIX Sharpe Ratio Rank: 15
WISIX Sortino Ratio Rank: 15
WISIX Omega Ratio Rank: 17
WISIX Calmar Ratio Rank: 19
WISIX Martin Ratio Rank: 16

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.

OBIOX vs. WISIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Oberweis International Opportunities Fund (OBIOX) 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.

Values are calculated on a 1-year rolling basis and updated daily. Risk-adjusted metrics are more stable over longer periods — use the period switch above to explore them.

	OBIOX	WISIX	Difference
Sharpe ratio: Return per unit of total volatility	1.21	1.01	+0.20
Sortino ratio: Return per unit of downside risk	1.75	1.49	+0.26
Omega ratio: Gain probability vs. loss probability	1.22	1.20	+0.02
Calmar ratio: Return relative to maximum drawdown	1.34	1.47	-0.13
Martin ratio: Return relative to average drawdown	4.63	3.99	+0.65

OBIOX vs. WISIX - Sharpe Ratio Comparison

The current OBIOX Sharpe Ratio is 1.21, which is comparable to the WISIX Sharpe Ratio of 1.01. The chart below compares the historical Sharpe Ratios of OBIOX 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.

Drawdowns

OBIOX vs. WISIX - Drawdown Comparison

The maximum OBIOX drawdown since its inception was -71.17%, which is greater than WISIX's maximum drawdown of -64.84%. Use the drawdown chart below to compare losses from any high point for OBIOX and WISIX.

Drawdown Indicators

	OBIOX	WISIX	Difference
Max Drawdown Largest peak-to-trough decline	-71.17%	-64.84%	-6.33%
Max Drawdown (1Y) Largest decline over 1 year	-15.64%	-10.09%	-5.55%
Max Drawdown (3Y) Largest decline over 3 years	-17.48%	-17.90%	+0.42%
Max Drawdown (5Y) Largest decline over 5 years	-51.47%	-47.76%	-3.71%
Max Drawdown (10Y) Largest decline over 10 years	-51.47%	-47.76%	-3.71%
Current Drawdown Current decline from peak	-9.21%	-9.41%	+0.20%
Average Drawdown Average peak-to-trough decline	-21.42%	-16.55%	-4.87%
Ulcer Index Depth and duration of drawdowns from previous peaks	4.51%	3.71%	+0.80%

Volatility

OBIOX vs. WISIX - Volatility Comparison

Oberweis International Opportunities Fund (OBIOX) and William Blair International Small Cap Growth Fund (WISIX) have volatilities of 6.61% and 6.44%, respectively, indicating that both stocks experience similar levels of price fluctuations. This suggests that the risk associated with both stocks, as measured by volatility, is nearly the same. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	OBIOX	WISIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	6.61%	6.44%	+0.17%
Volatility (6M) Calculated over the trailing 6-month period	15.06%	12.57%	+2.49%
Volatility (1Y) Calculated over the trailing 1-year period	17.35%	14.67%	+2.68%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	19.90%	17.45%	+2.45%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	19.85%	17.37%	+2.48%

OBIOX vs. WISIX - Expense Ratio Comparison

OBIOX has a 1.60% expense ratio, which is higher than WISIX's 1.23% expense ratio.

Dividends

OBIOX vs. WISIX - Dividend Comparison

OBIOX's dividend yield for the trailing twelve months is around 0.99%, more than WISIX's 0.54% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
OBIOX Oberweis International Opportunities Fund	0.99%	1.10%	1.27%	0.43%	0.00%	20.69%	0.40%	1.23%	17.03%	11.47%	0.07%	0.19%
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 OBIOX and WISIX in my portfolio?

OBIOX 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, OBIOX or WISIX?

OBIOX has higher volatility (6.61%) compared to WISIX (6.44%). In terms of maximum drawdown, OBIOX dropped -71.17% vs WISIX's -64.84%.

Which has better risk-adjusted returns?

OBIOX currently has the higher Sharpe Ratio (1.21 vs 1.01), 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.