MWNIX vs. WISIX

Last updated Jun 5, 2026

MWNIX (MFS International New Discovery Fund) and WISIX (William Blair International Small Cap Growth Fund) are both Foreign Small & Mid Cap Equities funds. Over the past 10 years, MWNIX returned 6.25%/yr vs 6.03%/yr for WISIX. Their correlation of 0.88 suggests significant overlap in exposure. MWNIX charges 1.03%/yr vs 1.23%/yr for WISIX.

Performance

MWNIX vs. WISIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in MFS International New Discovery Fund (MWNIX) 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, MWNIX achieves a 6.00% return, which is significantly lower than WISIX's 12.52% return. Both investments have delivered pretty close results over the past 10 years, with MWNIX having a 6.25% annualized return and WISIX not far behind at 6.03%.

MWNIX

• 1D: -0.81%
• 1M: 1.25%
• YTD: 6.00%
• 6M: 6.37%
• 1Y: 9.70%
• 3Y*: 9.82%
• 5Y*: 2.67%
• 10Y*: 6.25%

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)

MWNIX vs. WISIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
MWNIX MFS International New Discovery Fund	6.00%	16.88%	0.90%	13.03%	-18.63%	5.06%	9.98%	22.85%	-10.41%	30.67%
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%	32.71%

Correlation

The correlation between MWNIX and WISIX is 0.82, 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	0.82
Correlation (3Y) Calculated over the trailing 3-year period	0.83
Correlation (5Y) Calculated over the trailing 5-year period	0.86
Correlation (10Y) Calculated over the trailing 10-year period	0.86
Correlation (All Time) Calculated using the full available price history since Nov 3, 2005	0.88

The correlation between MWNIX and WISIX has been stable across timeframes, ranging from 0.82 to 0.88 - a consistent structural relationship.

Return for Risk

MWNIX vs. WISIX — Risk / Return Rank

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

MWNIX

MWNIX Risk / Return Rank: 12
MWNIX Sharpe Ratio Rank: 12
MWNIX Sortino Ratio Rank: 12
MWNIX Omega Ratio Rank: 12
MWNIX Calmar Ratio Rank: 10
MWNIX Martin Ratio Rank: 11

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.

MWNIX vs. WISIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for MFS International New Discovery Fund (MWNIX) 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.

	MWNIX	WISIX	Difference
Sharpe ratio: Return per unit of total volatility	0.90	0.98	-0.08
Sortino ratio: Return per unit of downside risk	1.35	1.45	-0.10
Omega ratio: Gain probability vs. loss probability	1.17	1.19	-0.02
Calmar ratio: Return relative to maximum drawdown	0.88	1.33	-0.45
Martin ratio: Return relative to average drawdown	3.02	3.69	-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.

MWNIX vs. WISIX - Sharpe Ratio Comparison

The current MWNIX Sharpe Ratio is 0.90, which is comparable to the WISIX Sharpe Ratio of 0.98. The chart below compares the historical Sharpe Ratios of MWNIX 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

	MWNIX	WISIX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	0.90	0.98	-0.08
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.20	0.03	+0.18
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.45	0.35	+0.10
Sharpe Ratio (All Time) Calculated using the full available price history	0.58	0.35	+0.23

Drawdowns

MWNIX vs. WISIX - Drawdown Comparison

The maximum MWNIX drawdown since its inception was -58.38%, smaller than the maximum WISIX drawdown of -64.84%. Use the drawdown chart below to compare losses from any high point for MWNIX and WISIX.

Drawdown Indicators

	MWNIX	WISIX	Difference
Max Drawdown Largest peak-to-trough decline	-58.38%	-64.84%	+6.46%
Max Drawdown (1Y) Largest decline over 1 year	-11.78%	-10.09%	-1.69%
Max Drawdown (3Y) Largest decline over 3 years	-15.12%	-17.90%	+2.78%
Max Drawdown (5Y) Largest decline over 5 years	-33.67%	-47.76%	+14.09%
Max Drawdown (10Y) Largest decline over 10 years	-34.72%	-47.76%	+13.04%
Current Drawdown Current decline from peak	-2.49%	-9.81%	+7.32%
Average Drawdown Average peak-to-trough decline	-9.57%	-16.56%	+6.99%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.42%	3.62%	-0.20%

Volatility

MWNIX vs. WISIX - Volatility Comparison

The current volatility for MFS International New Discovery Fund (MWNIX) is 3.60%, while William Blair International Small Cap Growth Fund (WISIX) has a volatility of 4.53%. This indicates that MWNIX 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

	MWNIX	WISIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.60%	4.53%	-0.93%
Volatility (6M) Calculated over the trailing 6-month period	9.51%	11.37%	-1.86%
Volatility (1Y) Calculated over the trailing 1-year period	11.52%	13.71%	-2.19%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	13.18%	17.29%	-4.11%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	13.99%	17.35%	-3.36%

MWNIX vs. WISIX - Expense Ratio Comparison

MWNIX has a 1.03% expense ratio, which is lower than WISIX's 1.23% expense ratio.

Dividends

MWNIX vs. WISIX - Dividend Comparison

MWNIX's dividend yield for the trailing twelve months is around 3.05%, more than WISIX's 0.54% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
MWNIX MFS International New Discovery Fund	3.05%	3.24%	7.61%	4.05%	5.68%	5.06%	3.90%	2.67%	6.68%	1.63%	1.09%	1.12%
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 MWNIX and WISIX in my portfolio?

MWNIX and WISIX have a correlation of 0.82, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, MWNIX or WISIX?

WISIX has higher volatility (4.53%) compared to MWNIX (3.60%). In terms of maximum drawdown, MWNIX dropped -58.38% vs WISIX's -64.84%.

Which has better risk-adjusted returns?

WISIX currently has the higher Sharpe Ratio (0.98 vs 0.90), 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.