WISIX vs. WBCIX

Last updated Jun 4, 2026

WISIX (William Blair International Small Cap Growth Fund) and WBCIX (William Blair Small-Mid Cap Core Fund) are both mutual funds - WISIX is a Foreign Small & Mid Cap Equities fund managed by William Blair, while WBCIX is a Small Cap Blend Equities fund managed by William Blair. Over the past 5 years, WISIX returned 0.64%/yr vs 5.31%/yr for WBCIX. A 0.59 correlation means they provide meaningful diversification when combined. WISIX charges 1.23%/yr vs 1.25%/yr for WBCIX.

Performance

WISIX vs. WBCIX - Performance Comparison

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

Returns By Period

The year-to-date returns for both stocks are quite close, with WISIX having a 12.59% return and WBCIX slightly lower at 12.39%.

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%

WBCIX

• 1D: 1.47%
• 1M: 5.78%
• YTD: 12.39%
• 6M: 12.52%
• 1Y: 21.24%
• 3Y*: 11.47%
• 5Y*: 5.31%
• 10Y*: —

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

WISIX vs. WBCIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019
WISIX William Blair International Small Cap Growth Fund	12.59%	15.31%	0.80%	14.72%	-34.99%	11.01%	29.09%	15.91%
WBCIX William Blair Small-Mid Cap Core Fund	12.39%	1.29%	12.04%	13.26%	-17.11%	26.63%	20.60%	10.29%

Correlation

The correlation between WISIX and WBCIX is 0.49, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.49
Correlation (3Y) Calculated over the trailing 3-year period	0.55
Correlation (5Y) Calculated over the trailing 5-year period	0.61
Correlation (All Time) Calculated using the full available price history since Oct 3, 2019	0.59

The correlation between WISIX and WBCIX shifts across timeframes, from 0.49 (1 year) to 0.61 (5 years), reflecting how their relationship changes across market environments.

Return for Risk

WISIX vs. WBCIX — Risk / Return Rank

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

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

WBCIX

WBCIX Risk / Return Rank: 26
WBCIX Sharpe Ratio Rank: 22
WBCIX Sortino Ratio Rank: 23
WBCIX Omega Ratio Rank: 22
WBCIX Calmar Ratio Rank: 30
WBCIX 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.

WISIX vs. WBCIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for William Blair International Small Cap Growth Fund (WISIX) and William Blair Small-Mid Cap Core Fund (WBCIX). 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.

	WISIX	WBCIX	Difference
Sharpe ratio: Return per unit of total volatility	0.93	1.35	-0.43
Sortino ratio: Return per unit of downside risk	1.37	2.01	-0.64
Omega ratio: Gain probability vs. loss probability	1.18	1.24	-0.06
Calmar ratio: Return relative to maximum drawdown	1.26	2.06	-0.81
Martin ratio: Return relative to average drawdown	3.49	7.21	-3.72
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

WISIX vs. WBCIX - Sharpe Ratio Comparison

The current WISIX Sharpe Ratio is 0.93, which is lower than the WBCIX Sharpe Ratio of 1.35. The chart below compares the historical Sharpe Ratios of WISIX and WBCIX, 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

	WISIX	WBCIX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	0.93	1.35	-0.43
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.04	0.26	-0.22
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.35	—	—
Sharpe Ratio (All Time) Calculated using the full available price history	0.35	0.47	-0.12

Drawdowns

WISIX vs. WBCIX - Drawdown Comparison

The maximum WISIX drawdown since its inception was -64.84%, which is greater than WBCIX's maximum drawdown of -39.56%. Use the drawdown chart below to compare losses from any high point for WISIX and WBCIX.

Drawdown Indicators

	WISIX	WBCIX	Difference
Max Drawdown Largest peak-to-trough decline	-64.84%	-39.56%	-25.28%
Max Drawdown (1Y) Largest decline over 1 year	-10.09%	-11.06%	+0.97%
Max Drawdown (3Y) Largest decline over 3 years	-17.90%	-23.53%	+5.63%
Max Drawdown (5Y) Largest decline over 5 years	-47.76%	-27.65%	-20.11%
Max Drawdown (10Y) Largest decline over 10 years	-47.76%	—	—
Current Drawdown Current decline from peak	-9.75%	0.00%	-9.75%
Average Drawdown Average peak-to-trough decline	-16.57%	-9.14%	-7.43%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.62%	3.15%	+0.47%

Volatility

WISIX vs. WBCIX - Volatility Comparison

The current volatility for William Blair International Small Cap Growth Fund (WISIX) is 4.53%, while William Blair Small-Mid Cap Core Fund (WBCIX) has a volatility of 5.07%. This indicates that WISIX experiences smaller price fluctuations and is considered to be less risky than WBCIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	WISIX	WBCIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.53%	5.07%	-0.54%
Volatility (6M) Calculated over the trailing 6-month period	11.48%	12.55%	-1.07%
Volatility (1Y) Calculated over the trailing 1-year period	13.72%	16.87%	-3.15%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	17.29%	20.70%	-3.41%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	17.36%	23.82%	-6.46%

WISIX vs. WBCIX - Expense Ratio Comparison

WISIX has a 1.23% expense ratio, which is lower than WBCIX's 1.25% expense ratio.

Dividends

WISIX vs. WBCIX - Dividend Comparison

WISIX's dividend yield for the trailing twelve months is around 0.54%, less than WBCIX's 2.66% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
WBCIX William Blair Small-Mid Cap Core Fund	2.66%	2.98%	1.35%	0.15%	0.00%	0.00%	0.00%	0.06%	0.00%	0.00%	0.00%	0.00%
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 WISIX and WBCIX in my portfolio?

WISIX and WBCIX have a correlation of 0.49, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, WISIX or WBCIX?

WBCIX has higher volatility (5.07%) compared to WISIX (4.53%). In terms of maximum drawdown, WISIX dropped -64.84% vs WBCIX's -39.56%.

Which has better risk-adjusted returns?

WBCIX currently has the higher Sharpe Ratio (1.35 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.