Morningstar

William Blair International Growth Fund Class I BIGIX

Medalist Rating as of Sep 30, 2026 See William Blair Investment Hub

Strategy

The investment seeks long-term capital appreciation. The fund normally invests at least 80% of its total assets in a diversified portfolio of equity securities, including common stocks and other forms of equity investments, issued by companies of all sizes domiciled outside the U.S. that the adviser believes have above-average growth, profitability and quality characteristics. Its investments are normally allocated among at least six different countries and no more than 50% of the fund's equity holdings may be invested in securities of issuers in one country at any given time.

Ticker	Name	Share Class Type	Investment Status	Morningstar Rating for Funds Overall	Medalist Rating Overall	Inception Date	Total Net Assets for Share Class	Adjusted Expense Ratio	Fee Level Distribution	Minimum Initial Investment	1-Year Net Flow
WBIGX	William Blair International Growth Fund Class N	No Load	Open			Oct 1, 1992	$204.87M	1.150%	High	$2,500	−$59.27M
BIGIX	William Blair International Growth Fund Class I	Institutional	Open			Oct 1, 1999	$681.47M	0.900%	Above Average	$500,000	−$242.30M
WBIRX	William Blair International Growth Fund Class R6	Retirement, Large	Open			May 2, 2019	$90.41M	0.850%	Above Average	$1M	−$13.46M

Sponsor Center

Transparency is our policy. Learn how it impacts everything we do

Transparency is how we protect the integrity of our work and keep empowering investors to achieve their goals and dreams. And we have unwavering standards for how we keep that integrity intact, from our research and data to our policies on content and your personal data.

We’d like to share more about how we work and what drives our day-to-day business.

How we make money

We sell different types of products and services to both investment professionals and individual investors. These products and services are usually sold through license agreements or subscriptions. Our investment management business generates asset-based fees, which are calculated as a percentage of assets under management. We also sell both admissions and sponsorship packages for our investment conferences and advertising on our websites and newsletters.

How we use your personal data

How we use your information depends on the product and service that you use and your relationship with us. We may use it to:

Verify your identity, personalize the content you receive, or create and administer your account.
Provide specific products and services to you, such as portfolio management or data aggregation.
Develop and improve features of our offerings.
Gear advertisements and other marketing efforts towards your interests.

To learn more about how we handle and protect your data, visit our privacy center.

How we approach editorial content

Maintaining independence and editorial freedom is essential to our mission of empowering investor success. We provide a platform for our authors to report on investments fairly, accurately, and from the investor’s point of view. We also respect individual opinions––they represent the unvarnished thinking of our people and exacting analysis of our research processes. Our authors can publish views that we may or may not agree with, but they show their work, distinguish facts from opinions, and make sure their analysis is clear and in no way misleading or deceptive.

To further protect the integrity of our editorial content, we keep a strict separation between our sales teams and authors to remove any pressure or influence on our analyses and research.

Read our editorial policy to learn more about our process.

© Copyright 2026 Morningstar, Inc. All rights reserved. Dow Jones Industrial Average, S&P 500, Nasdaq, and Morningstar Index (Market Barometer) quotes are real-time.