WBIIX vs. WILIX

Last updated Jun 24, 2026

WBIIX (William Blair Institutional International Growth Fund) and WILIX (William Blair International Leaders Fund) are both Foreign Large Cap Equities funds from William Blair. Over the past 10 years, WBIIX returned 9.65%/yr vs 9.99%/yr for WILIX. With a 0.97 correlation, they move nearly in lockstep. WBIIX charges 0.98%/yr vs 0.90%/yr for WILIX.

Performance

WBIIX vs. WILIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in William Blair Institutional International Growth Fund (WBIIX) and William Blair International Leaders Fund (WILIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

The year-to-date returns for both investments are quite close, with WBIIX having a 18.59% return and WILIX slightly higher at 18.80%. Both investments have delivered pretty close results over the past 10 years, with WBIIX having a 9.65% annualized return and WILIX not far ahead at 9.99%.

WBIIX

• 1D: 0.77%
• 1M: 5.32%
• YTD: 18.59%
• 6M: 18.92%
• 1Y: 28.43%
• 3Y*: 14.75%
• 5Y*: 3.67%
• 10Y*: 9.65%

WILIX

• 1D: 1.63%
• 1M: 4.92%
• YTD: 18.80%
• 6M: 19.51%
• 1Y: 30.86%
• 3Y*: 14.51%
• 5Y*: 4.02%
• 10Y*: 9.99%

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

WBIIX vs. WILIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
WBIIX William Blair Institutional International Growth Fund	18.59%	18.16%	2.40%	15.23%	-28.39%	9.30%	32.69%	30.75%	-17.49%	29.51%
WILIX William Blair International Leaders Fund	18.80%	23.21%	-0.50%	13.10%	-28.55%	10.16%	26.79%	31.76%	-12.43%	30.03%

Correlation

The correlation between WBIIX and WILIX is 0.92, 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	0.92
Correlation (3Y) Calculated over the trailing 3-year period	0.96
Correlation (5Y) Calculated over the trailing 5-year period	0.97
Correlation (10Y) Calculated over the trailing 10-year period	0.97
Correlation (All Time) Calculated using the full available price history since Jan 2, 2013	0.97

The correlation between WBIIX and WILIX has been stable across timeframes, ranging from 0.92 to 0.97 - a consistent structural relationship.

Return for Risk

WBIIX vs. WILIX — Risk / Return Rank

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

WBIIX

WBIIX Risk / Return Rank: 41
WBIIX Sharpe Ratio Rank: 42
WBIIX Sortino Ratio Rank: 39
WBIIX Omega Ratio Rank: 48
WBIIX Calmar Ratio Rank: 37
WBIIX Martin Ratio Rank: 40

WILIX

WILIX Risk / Return Rank: 43
WILIX Sharpe Ratio Rank: 44
WILIX Sortino Ratio Rank: 39
WILIX Omega Ratio Rank: 48
WILIX Calmar Ratio Rank: 41
WILIX Martin Ratio Rank: 42

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.

WBIIX vs. WILIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for William Blair Institutional International Growth Fund (WBIIX) and William Blair International Leaders Fund (WILIX). 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.

	WBIIX	WILIX	Difference
Sharpe ratio: Return per unit of total volatility	1.76	1.80	-0.04
Sortino ratio: Return per unit of downside risk	2.41	2.43	-0.01
Omega ratio: Gain probability vs. loss probability	1.35	1.35	0.00
Calmar ratio: Return relative to maximum drawdown	2.20	2.31	-0.11
Martin ratio: Return relative to average drawdown	8.19	8.45	-0.26

WBIIX vs. WILIX - Sharpe Ratio Comparison

The current WBIIX Sharpe Ratio is 1.76, which is comparable to the WILIX Sharpe Ratio of 1.80. The chart below compares the historical Sharpe Ratios of WBIIX and WILIX, 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

WBIIX vs. WILIX - Drawdown Comparison

The maximum WBIIX drawdown since its inception was -65.13%, which is greater than WILIX's maximum drawdown of -41.01%. Use the drawdown chart below to compare losses from any high point for WBIIX and WILIX.

Drawdown Indicators

	WBIIX	WILIX	Difference
Max Drawdown Largest peak-to-trough decline	-65.13%	-41.01%	-24.12%
Max Drawdown (1Y) Largest decline over 1 year	-13.17%	-13.67%	+0.50%
Max Drawdown (3Y) Largest decline over 3 years	-17.06%	-18.21%	+1.15%
Max Drawdown (5Y) Largest decline over 5 years	-40.91%	-41.01%	+0.10%
Max Drawdown (10Y) Largest decline over 10 years	-40.91%	-41.01%	+0.10%
Current Drawdown Current decline from peak	0.00%	0.00%	0.00%
Average Drawdown Average peak-to-trough decline	-14.77%	-9.75%	-5.02%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.52%	3.72%	-0.20%

Volatility

WBIIX vs. WILIX - Volatility Comparison

William Blair Institutional International Growth Fund (WBIIX) and William Blair International Leaders Fund (WILIX) have volatilities of 7.57% and 7.60%, 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

	WBIIX	WILIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	7.57%	7.60%	-0.03%
Volatility (6M) Calculated over the trailing 6-month period	14.45%	15.27%	-0.82%
Volatility (1Y) Calculated over the trailing 1-year period	16.45%	17.56%	-1.11%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	16.95%	18.08%	-1.13%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	17.25%	17.81%	-0.56%

WBIIX vs. WILIX - Expense Ratio Comparison

WBIIX has a 0.98% expense ratio, which is higher than WILIX's 0.90% expense ratio.

Dividends

WBIIX vs. WILIX - Dividend Comparison

WBIIX's dividend yield for the trailing twelve months is around 10.56%, more than WILIX's 6.72% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
WBIIX William Blair Institutional International Growth Fund	10.56%	12.53%	7.49%	2.51%	6.57%	16.58%	12.61%	0.95%	11.74%	4.16%	1.15%	1.28%
WILIX William Blair International Leaders Fund	6.72%	7.98%	0.58%	0.45%	0.19%	2.82%	0.80%	0.56%	4.14%	2.17%	1.01%	0.74%

Frequently Asked Questions

Can I hold both WBIIX and WILIX in my portfolio?

With a correlation of 0.92, WBIIX and WILIX move almost identically. Holding both adds very little diversification - you're essentially doubling your position in the same market segment. Choosing one is usually more capital-efficient.

Which is riskier, WBIIX or WILIX?

WILIX has higher volatility (7.60%) compared to WBIIX (7.57%). In terms of maximum drawdown, WBIIX dropped -65.13% vs WILIX's -41.01%.

Which has better risk-adjusted returns?

WILIX currently has the higher Sharpe Ratio (1.80 vs 1.76), 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.