HIISX vs. WISIX

Last updated Jun 5, 2026

HIISX (Harbor International Small Cap Fund) and WISIX (William Blair International Small Cap Growth Fund) are both Foreign Small & Mid Cap Equities funds. Over the past 5 years, HIISX returned 5.75%/yr vs 0.48%/yr for WISIX. A 0.77 correlation means they provide meaningful diversification when combined. HIISX charges 1.32%/yr vs 1.23%/yr for WISIX.

Performance

HIISX vs. WISIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Harbor International Small Cap Fund (HIISX) 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, HIISX achieves a 11.50% return, which is significantly lower than WISIX's 12.52% return.

HIISX

• 1D: -0.63%
• 1M: 2.72%
• YTD: 11.50%
• 6M: 13.88%
• 1Y: 20.40%
• 3Y*: 12.63%
• 5Y*: 5.75%
• 10Y*: —

WISIX

• 1D: -0.06%
• 1M: 1.28%
• YTD: 12.52%
• 6M: 15.10%
• 1Y: 12.18%
• 3Y*: 10.90%
• 5Y*: 0.48%
• 10Y*: 6.03%

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

HIISX vs. WISIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
HIISX Harbor International Small Cap Fund	11.50%	24.37%	-1.12%	8.90%	-8.70%	16.70%	7.75%	21.61%	-19.71%	37.11%
WISIX William Blair International Small Cap Growth Fund	12.52%	15.31%	0.80%	14.72%	-34.99%	11.01%	29.09%	34.22%	-24.27%	32.81%

Correlation

The correlation between HIISX and WISIX is 0.70, which is moderate. They share some common price drivers but move independently often enough to provide real diversification benefit when combined.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.70
Correlation (3Y) Calculated over the trailing 3-year period	0.75
Correlation (5Y) Calculated over the trailing 5-year period	0.78
Correlation (All Time) Calculated using the full available price history since Jan 4, 2017	0.77

The correlation between HIISX and WISIX has been stable across timeframes, ranging from 0.70 to 0.78 - a consistent structural relationship.

Return for Risk

HIISX vs. WISIX — Risk / Return Rank

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

HIISX

HIISX Risk / Return Rank: 30
HIISX Sharpe Ratio Rank: 31
HIISX Sortino Ratio Rank: 32
HIISX Omega Ratio Rank: 31
HIISX Calmar Ratio Rank: 29
HIISX Martin Ratio Rank: 27

WISIX

WISIX Risk / Return Rank: 14
WISIX Sharpe Ratio Rank: 13
WISIX Sortino Ratio Rank: 13
WISIX Omega Ratio Rank: 14
WISIX Calmar Ratio Rank: 16
WISIX Martin Ratio Rank: 13

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.

HIISX vs. WISIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Harbor International Small Cap Fund (HIISX) 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.

	HIISX	WISIX	Difference
Sharpe ratio: Return per unit of total volatility	1.55	0.98	+0.57
Sortino ratio: Return per unit of downside risk	2.29	1.45	+0.84
Omega ratio: Gain probability vs. loss probability	1.28	1.19	+0.09
Calmar ratio: Return relative to maximum drawdown	1.94	1.33	+0.61
Martin ratio: Return relative to average drawdown	6.21	3.69	+2.52
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

HIISX vs. WISIX - Sharpe Ratio Comparison

The current HIISX Sharpe Ratio is 1.55, which is higher than the WISIX Sharpe Ratio of 0.98. The chart below compares the historical Sharpe Ratios of HIISX 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

	HIISX	WISIX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.55	0.98	+0.57
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.37	0.03	+0.34
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	—	0.35	—
Sharpe Ratio (All Time) Calculated using the full available price history	0.57	0.35	+0.22

Drawdowns

HIISX vs. WISIX - Drawdown Comparison

The maximum HIISX drawdown since its inception was -42.19%, smaller than the maximum WISIX drawdown of -64.84%. Use the drawdown chart below to compare losses from any high point for HIISX and WISIX.

Drawdown Indicators

	HIISX	WISIX	Difference
Max Drawdown Largest peak-to-trough decline	-42.19%	-64.84%	+22.65%
Max Drawdown (1Y) Largest decline over 1 year	-10.93%	-10.09%	-0.84%
Max Drawdown (3Y) Largest decline over 3 years	-15.37%	-17.90%	+2.53%
Max Drawdown (5Y) Largest decline over 5 years	-26.11%	-47.76%	+21.65%
Max Drawdown (10Y) Largest decline over 10 years	—	-47.76%	—
Current Drawdown Current decline from peak	-1.76%	-9.81%	+8.05%
Average Drawdown Average peak-to-trough decline	-8.84%	-16.56%	+7.72%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.41%	3.62%	-0.21%

Volatility

HIISX vs. WISIX - Volatility Comparison

The current volatility for Harbor International Small Cap Fund (HIISX) is 3.67%, while William Blair International Small Cap Growth Fund (WISIX) has a volatility of 4.53%. This indicates that HIISX experiences smaller price fluctuations and is considered to be less risky than WISIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	HIISX	WISIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.67%	4.53%	-0.86%
Volatility (6M) Calculated over the trailing 6-month period	10.44%	11.37%	-0.93%
Volatility (1Y) Calculated over the trailing 1-year period	13.65%	13.71%	-0.06%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	15.63%	17.29%	-1.66%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	16.26%	17.35%	-1.09%

HIISX vs. WISIX - Expense Ratio Comparison

HIISX has a 1.32% expense ratio, which is higher than WISIX's 1.23% expense ratio.

Dividends

HIISX vs. WISIX - Dividend Comparison

HIISX's dividend yield for the trailing twelve months is around 7.99%, more than WISIX's 0.54% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
HIISX Harbor International Small Cap Fund	7.99%	8.91%	4.71%	1.84%	2.22%	6.97%	0.93%	2.35%	3.78%	0.99%	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 HIISX and WISIX in my portfolio?

HIISX and WISIX have a correlation of 0.70, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, HIISX or WISIX?

WISIX has higher volatility (4.53%) compared to HIISX (3.67%). In terms of maximum drawdown, HIISX dropped -42.19% vs WISIX's -64.84%.

Which has better risk-adjusted returns?

HIISX currently has the higher Sharpe Ratio (1.55 vs 0.98), 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.