VIEIX vs. WSMDX

Last updated Jun 4, 2026

VIEIX (Vanguard Extended Market Index Fund Institutional Shares) and WSMDX (William Blair Small-Mid Cap Growth Fund) are both mutual funds - VIEIX is a Mid Cap Blend Equities fund managed by Vanguard, while WSMDX is a Mid Cap Growth Equities fund managed by William Blair. Over the past 10 years, VIEIX returned 12.20%/yr vs 12.53%/yr for WSMDX. Their correlation of 0.95 suggests significant overlap in exposure. VIEIX charges 0.05%/yr vs 1.10%/yr for WSMDX.

Performance

VIEIX vs. WSMDX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Vanguard Extended Market Index Fund Institutional Shares (VIEIX) and William Blair Small-Mid Cap Growth Fund (WSMDX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, VIEIX achieves a 14.93% return, which is significantly higher than WSMDX's 12.98% return. Both investments have delivered pretty close results over the past 10 years, with VIEIX having a 12.20% annualized return and WSMDX not far ahead at 12.53%.

VIEIX

• 1D: 1.07%
• 1M: 5.81%
• YTD: 14.93%
• 6M: 13.66%
• 1Y: 30.15%
• 3Y*: 20.15%
• 5Y*: 6.92%
• 10Y*: 12.20%

WSMDX

• 1D: 1.08%
• 1M: 5.09%
• YTD: 12.98%
• 6M: 12.13%
• 1Y: 25.70%
• 3Y*: 16.93%
• 5Y*: 6.76%
• 10Y*: 12.53%

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

VIEIX vs. WSMDX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
VIEIX Vanguard Extended Market Index Fund Institutional Shares	14.93%	11.42%	15.49%	26.97%	-26.46%	12.46%	32.24%	28.05%	-9.36%	18.12%
WSMDX William Blair Small-Mid Cap Growth Fund	12.98%	0.63%	27.55%	18.14%	-22.98%	8.28%	32.38%	30.81%	-2.18%	28.85%

Correlation

The correlation between VIEIX and WSMDX is 0.94, 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	0.94
Correlation (3Y) Calculated over the trailing 3-year period	0.94
Correlation (5Y) Calculated over the trailing 5-year period	0.96
Correlation (10Y) Calculated over the trailing 10-year period	0.94
Correlation (All Time) Calculated using the full available price history since Dec 31, 2003	0.95

The correlation between VIEIX and WSMDX has been stable across timeframes, ranging from 0.94 to 0.96 - a consistent structural relationship.

Return for Risk

VIEIX vs. WSMDX — Risk / Return Rank

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

VIEIX

VIEIX Risk / Return Rank: 47
VIEIX Sharpe Ratio Rank: 41
VIEIX Sortino Ratio Rank: 39
VIEIX Omega Ratio Rank: 36
VIEIX Calmar Ratio Rank: 66
VIEIX Martin Ratio Rank: 55

WSMDX

WSMDX Risk / Return Rank: 32
WSMDX Sharpe Ratio Rank: 28
WSMDX Sortino Ratio Rank: 27
WSMDX Omega Ratio Rank: 25
WSMDX Calmar Ratio Rank: 40
WSMDX Martin Ratio Rank: 41

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.

VIEIX vs. WSMDX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Vanguard Extended Market Index Fund Institutional Shares (VIEIX) and William Blair Small-Mid Cap Growth Fund (WSMDX). 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.

	VIEIX	WSMDX	Difference
Sharpe ratio: Return per unit of total volatility	1.87	1.51	+0.36
Sortino ratio: Return per unit of downside risk	2.61	2.18	+0.43
Omega ratio: Gain probability vs. loss probability	1.32	1.26	+0.06
Calmar ratio: Return relative to maximum drawdown	3.13	2.39	+0.74
Martin ratio: Return relative to average drawdown	11.08	8.82	+2.27
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

VIEIX vs. WSMDX - Sharpe Ratio Comparison

The current VIEIX Sharpe Ratio is 1.87, which is comparable to the WSMDX Sharpe Ratio of 1.51. The chart below compares the historical Sharpe Ratios of VIEIX and WSMDX, 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

	VIEIX	WSMDX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.87	1.51	+0.36
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.31	0.30	+0.02
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.55	0.57	-0.03
Sharpe Ratio (All Time) Calculated using the full available price history	0.40	0.54	-0.14

Drawdowns

VIEIX vs. WSMDX - Drawdown Comparison

The maximum VIEIX drawdown since its inception was -58.03%, which is greater than WSMDX's maximum drawdown of -50.33%. Use the drawdown chart below to compare losses from any high point for VIEIX and WSMDX.

Drawdown Indicators

	VIEIX	WSMDX	Difference
Max Drawdown Largest peak-to-trough decline	-58.03%	-50.33%	-7.70%
Max Drawdown (1Y) Largest decline over 1 year	-10.25%	-11.50%	+1.25%
Max Drawdown (3Y) Largest decline over 3 years	-26.84%	-25.63%	-1.21%
Max Drawdown (5Y) Largest decline over 5 years	-36.32%	-36.89%	+0.57%
Max Drawdown (10Y) Largest decline over 10 years	-41.62%	-36.89%	-4.73%
Current Drawdown Current decline from peak	0.00%	0.00%	0.00%
Average Drawdown Average peak-to-trough decline	-13.84%	-8.46%	-5.38%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.89%	3.11%	-0.22%

Volatility

VIEIX vs. WSMDX - Volatility Comparison

The current volatility for Vanguard Extended Market Index Fund Institutional Shares (VIEIX) is 4.69%, while William Blair Small-Mid Cap Growth Fund (WSMDX) has a volatility of 5.52%. This indicates that VIEIX experiences smaller price fluctuations and is considered to be less risky than WSMDX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	VIEIX	WSMDX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.69%	5.52%	-0.83%
Volatility (6M) Calculated over the trailing 6-month period	12.46%	14.15%	-1.69%
Volatility (1Y) Calculated over the trailing 1-year period	17.17%	18.26%	-1.09%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	22.34%	23.05%	-0.71%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	22.36%	21.94%	+0.42%

VIEIX vs. WSMDX - Expense Ratio Comparison

VIEIX has a 0.05% expense ratio, which is lower than WSMDX's 1.10% expense ratio.

Dividends

VIEIX vs. WSMDX - Dividend Comparison

VIEIX's dividend yield for the trailing twelve months is around 1.01%, less than WSMDX's 2.49% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
VIEIX Vanguard Extended Market Index Fund Institutional Shares	1.01%	1.14%	1.10%	1.26%	1.16%	1.14%	1.08%	1.31%	1.67%	1.27%	1.45%	1.37%
WSMDX William Blair Small-Mid Cap Growth Fund	2.49%	2.81%	24.90%	7.89%	3.34%	9.30%	1.66%	7.13%	8.88%	5.33%	2.64%	5.31%

Frequently Asked Questions

Can I hold both VIEIX and WSMDX in my portfolio?

With a correlation of 0.94, VIEIX and WSMDX 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, VIEIX or WSMDX?

WSMDX has higher volatility (5.52%) compared to VIEIX (4.69%). In terms of maximum drawdown, VIEIX dropped -58.03% vs WSMDX's -50.33%.

Which has better risk-adjusted returns?

VIEIX currently has the higher Sharpe Ratio (1.87 vs 1.51), 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.