William Blair Small Cap Growth Fund Class I (WBSIX)

Fund Assets	1.12B
Expense Ratio	1.033%
Min. Investment	$500,000
Turnover	94.00%
Dividend (ttm)	n/a
Dividend Yield	n/a
Dividend Growth	n/a
Payout Frequency	Annual
Ex-Dividend Date	Dec 18, 2025

Previous Close	39.08
YTD Return	15.42%
1-Year Return	20.57%
5-Year Return	27.94%
52-Week Low	32.09
52-Week High	41.62
Beta (5Y)	1.10
Holdings	92
Inception Date	Dec 27, 1999

About WBSIX

William Blair Small Cap Growth Fund Class I is an actively managed mutual fund focused on delivering long-term capital appreciation by investing primarily in equity securities of small-cap U.S. companies exhibiting strong growth potential. The fund targets firms at the lower end of the market-capitalization spectrum that demonstrate accelerated earnings, sales, or cash flow growth, often operating in emerging or rapidly evolving industries. This strategy results in a portfolio that tends to emphasize innovation-driven businesses and early-stage market leaders, spanning sectors such as industrials, healthcare, technology, and consumer goods. Designed for institutional investors, the fund maintains a diversified approach to help mitigate the inherent volatility associated with smaller, high-growth companies. By carefully selecting holdings based on quality and growth prospects, the fund aims to outperform standard small-cap growth benchmarks over time. With a sizable asset base and an expense structure positioned competitively within its peer group, William Blair Small Cap Growth Fund Class I plays a significant role as a potential engine of growth within a broader diversified investment portfolio, contributing exposure to dynamic segments of the equity market.

• Fund Family: William Blair
• Category: Small Growth
• Performance Rating: Above Average
• Risk Rating: Average
• Stock Exchange: Nasdaq
• Ticker Symbol: WBSIX
• Share Class: Class I
• Index: Russell 2000 Growth TR

Performance

WBSIX had a total return of 20.57% in the past year, including dividends. Since the fund's inception, the average annual return has been 12.27%.

Equivalent Funds

These are funds that follow the same index from the other major fund companies.

Symbol	Provider	Name	Expense Ratio
VRTGX	Vanguard	Vanguard Russell 2000 Growth Index Fund Institutional Shares	0.07%

Other Share Classes

These are alternative share classes of the same fund, from the same provider.

Symbol	Share Class	Expense Ratio
WBSRX	Class R6	0.94%
WBSNX	Class N	1.24%

Top 10 Holdings

20.13% of assets

Name	Symbol	Weight
Fixed Inc Clearing Corp.Repo	n/a	3.71%
Twist Bioscience Corporation	TWST	2.41%
Merit Medical Systems, Inc.	MMSI	2.09%
Repligen Corporation	RGEN	1.77%
Diebold Nixdorf, Incorporated	DBD	1.73%
Vericel Corporation	VCEL	1.72%
Elastic N.V.	ESTC	1.70%
Grand Canyon Education, Inc.	LOPE	1.68%
BorgWarner Inc.	BWA	1.66%
Veracyte, Inc.	VCYT	1.66%

Dividend History

Ex-Dividend	Amount	Pay Date
Dec 18, 2025	$2.5351	Dec 19, 2025
Dec 19, 2024	$3.55983	Dec 20, 2024
Dec 14, 2023	$0.49993	Dec 15, 2023
Dec 15, 2022	$1.01206	Dec 16, 2022
Dec 16, 2021	$6.69889	Dec 17, 2021
Dec 17, 2020	$3.83162	Dec 18, 2020

Data Sources: Tiingo, Financial Modeling Prep, and more

Historical data is provided by Tiingo. Delayed stock pricing data is provided by Financial Modeling Prep. Several fund data points are also provided by Finnhub.

Last checked:

Nov 11, 2026

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