BGFIX vs. WBSIX

Last updated Jun 4, 2026

BGFIX (William Blair Growth Fund) and WBSIX (William Blair Small Cap Growth Fund) are both mutual funds - BGFIX is a Large Cap Growth Equities fund tracking the Russell 3000® Growth Index, while WBSIX is a Small Cap Growth Equities fund managed by William Blair. Over the past 10 years, BGFIX returned 15.45%/yr vs 14.81%/yr for WBSIX. Their correlation of 0.85 suggests significant overlap in exposure. BGFIX charges 0.89%/yr vs 1.25%/yr for WBSIX.

Performance

BGFIX vs. WBSIX - Performance Comparison

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

Returns By Period

In the year-to-date period, BGFIX achieves a 10.53% return, which is significantly lower than WBSIX's 16.21% return. Both investments have delivered pretty close results over the past 10 years, with BGFIX having a 15.45% annualized return and WBSIX not far behind at 14.81%.

BGFIX

• 1D: -0.25%
• 1M: 9.33%
• YTD: 10.53%
• 6M: 9.06%
• 1Y: 25.69%
• 3Y*: 19.13%
• 5Y*: 10.61%
• 10Y*: 15.45%

WBSIX

• 1D: 1.44%
• 1M: 5.64%
• YTD: 16.21%
• 6M: 16.70%
• 1Y: 31.29%
• 3Y*: 19.68%
• 5Y*: 8.35%
• 10Y*: 14.81%

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

BGFIX vs. WBSIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
BGFIX William Blair Growth Fund	10.53%	10.83%	22.26%	38.13%	-29.60%	22.24%	36.48%	32.43%	5.25%	24.53%
WBSIX William Blair Small Cap Growth Fund	16.21%	3.03%	32.88%	16.38%	-21.46%	12.64%	38.87%	22.53%	-2.08%	26.81%

Correlation

The correlation between BGFIX and WBSIX is 0.74, 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	0.75
Correlation (3Y) Calculated over the trailing 3-year period	0.78
Correlation (5Y) Calculated over the trailing 5-year period	0.84
Correlation (10Y) Calculated over the trailing 10-year period	0.83
Correlation (All Time) Calculated using the full available price history since Dec 28, 1999	0.85

The correlation between BGFIX and WBSIX shifts across timeframes, from 0.74 (1 year) to 0.85 (all time), reflecting how their relationship changes across market environments.

Return for Risk

BGFIX vs. WBSIX — Risk / Return Rank

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

BGFIX

BGFIX Risk / Return Rank: 24
BGFIX Sharpe Ratio Rank: 32
BGFIX Sortino Ratio Rank: 28
BGFIX Omega Ratio Rank: 30
BGFIX Calmar Ratio Rank: 15
BGFIX Martin Ratio Rank: 14

WBSIX

WBSIX Risk / Return Rank: 38
WBSIX Sharpe Ratio Rank: 34
WBSIX Sortino Ratio Rank: 33
WBSIX Omega Ratio Rank: 29
WBSIX Calmar Ratio Rank: 47
WBSIX Martin Ratio Rank: 45

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.

BGFIX vs. WBSIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for William Blair Growth Fund (BGFIX) and William Blair Small Cap Growth Fund (WBSIX). 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.

	BGFIX	WBSIX	Difference
Sharpe ratio: Return per unit of total volatility	1.62	1.67	-0.05
Sortino ratio: Return per unit of downside risk	2.22	2.41	-0.19
Omega ratio: Gain probability vs. loss probability	1.29	1.28	+0.01
Calmar ratio: Return relative to maximum drawdown	1.37	2.62	-1.25
Martin ratio: Return relative to average drawdown	3.90	9.46	-5.56
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

BGFIX vs. WBSIX - Sharpe Ratio Comparison

The current BGFIX Sharpe Ratio is 1.62, which is comparable to the WBSIX Sharpe Ratio of 1.67. The chart below compares the historical Sharpe Ratios of BGFIX and WBSIX, 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

	BGFIX	WBSIX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.62	1.67	-0.05
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.50	0.35	+0.14
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.75	0.65	+0.11
Sharpe Ratio (All Time) Calculated using the full available price history	0.43	0.54	-0.12

Drawdowns

BGFIX vs. WBSIX - Drawdown Comparison

The maximum BGFIX drawdown since its inception was -53.45%, smaller than the maximum WBSIX drawdown of -62.35%. Use the drawdown chart below to compare losses from any high point for BGFIX and WBSIX.

Drawdown Indicators

	BGFIX	WBSIX	Difference
Max Drawdown Largest peak-to-trough decline	-53.45%	-62.35%	+8.90%
Max Drawdown (1Y) Largest decline over 1 year	-19.83%	-12.75%	-7.08%
Max Drawdown (3Y) Largest decline over 3 years	-25.34%	-24.76%	-0.58%
Max Drawdown (5Y) Largest decline over 5 years	-36.70%	-38.13%	+1.43%
Max Drawdown (10Y) Largest decline over 10 years	-36.70%	-39.16%	+2.46%
Current Drawdown Current decline from peak	-0.25%	0.00%	-0.25%
Average Drawdown Average peak-to-trough decline	-13.41%	-11.14%	-2.27%
Ulcer Index Depth and duration of drawdowns from previous peaks	6.92%	3.51%	+3.41%

Volatility

BGFIX vs. WBSIX - Volatility Comparison

The current volatility for William Blair Growth Fund (BGFIX) is 4.55%, while William Blair Small Cap Growth Fund (WBSIX) has a volatility of 5.64%. This indicates that BGFIX experiences smaller price fluctuations and is considered to be less risky than WBSIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	BGFIX	WBSIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.55%	5.64%	-1.09%
Volatility (6M) Calculated over the trailing 6-month period	12.65%	14.48%	-1.83%
Volatility (1Y) Calculated over the trailing 1-year period	16.75%	20.00%	-3.25%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	21.52%	23.85%	-2.33%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	20.57%	23.03%	-2.46%

BGFIX vs. WBSIX - Expense Ratio Comparison

BGFIX has a 0.89% expense ratio, which is lower than WBSIX's 1.25% expense ratio.

Dividends

BGFIX vs. WBSIX - Dividend Comparison

BGFIX's dividend yield for the trailing twelve months is around 24.40%, more than WBSIX's 6.44% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
BGFIX William Blair Growth Fund	24.40%	26.97%	24.13%	9.67%	3.60%	11.74%	12.31%	8.62%	33.23%	34.05%	8.35%	12.91%
WBSIX William Blair Small Cap Growth Fund	6.44%	7.49%	20.14%	1.53%	3.55%	17.85%	9.73%	2.07%	12.60%	16.89%	5.42%	8.25%

Frequently Asked Questions

Can I hold both BGFIX and WBSIX in my portfolio?

BGFIX and WBSIX have a correlation of 0.74, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, BGFIX or WBSIX?

WBSIX has higher volatility (5.64%) compared to BGFIX (4.55%). In terms of maximum drawdown, BGFIX dropped -53.45% vs WBSIX's -62.35%.

Which has better risk-adjusted returns?

WBSIX currently has the higher Sharpe Ratio (1.67 vs 1.62), 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.