Who We Are

AT A GLANCE

$71.7 billion

total assets under management¹

29% of our AUM

is from clients with multiple strategies

26 of 79

portfolio managers/analysts are partners

29

countries in which we have clients

26 years

average industry experience for portfolio managers

10.0 years

average client tenure

All data as of 06/30/2026

¹Total assets and total strategy assets are inclusive of total discretionary assets under management (AUM) as well as non-discretionary assets under advisement (AUA), as indicated. AUA generally consists of non-discretionary advisory assets managed by third parties in accordance with investment model portfolios provided by William Blair Investment Management, LLC (William Blair). William Blair receives an asset-based fee on AUA but does not exercise investment discretion or trading authority over such assets. All AUA data is reported on a one-month lag.

William Blair’s measure of AUM/AUA for these purposes may differ from the calculations employed by other investment managers and, as a result, may not be directly comparable. This measure also differs from the manner in which William Blair is required to report assets under management in certain regulatory filings.

Who We Are

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Learn more about what makes William Blair Investment Management unique.

A Recognized Workplace

Lewis Jones, Marcelo Assalin, and Marco Ruijer Named to Euro Stars 2026

Lewis Jones, CFA, FRM, local currency portfolio manager; Marcelo Assalin, CFA, partner, head of the emerging markets debt team, and portfolio manager; and Marco Ruijer, CFA, partner and portfolio manager—have been named to Citywire’s Euro Stars 2026 list.

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William Blair Investment Management Named a Best Place to Work in Money Management

For the 13th year, WBIM has been named a 2025 Best Place to Work in Money Management by Pensions & Investments.

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WBIM Recognized by Citywire Asia as the Best EM Local Currency Fixed Income Manager

William Blair Investment Management has been recognized as the Best Emerging Markets Local Currency Fixed Income Manager by Citywire Asia.

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William Blair Named One of the Top Workplaces in Chicago for 2025

William Blair was named one of Chicago’s Top Workplaces for 2025 by the Chicago Tribune on November 5.

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Vivian Lin Thurston Named a P&I Most Influential Woman in Institutional Investing

Vivian Lin Thurston, CFA, partner, portfolio manager, has been named a Pensions & Investments 2024 Most Influential Women in Institutional Investing.

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Ward Sexton and Dan Crowe Named to Euro Stars 2024

Ward Sexton, CFA, partner, and Dan Crowe, CFA, partner, both portfolio managers, have been listed among Europe’s top fund managers in Citywire’s Euro Stars 2024 list.

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Connecting Clients to Opportunities

Our investment teams are committed to delivering results across strategies such as global equity, U.S. growth and core equity, U.S. value equity, and emerging markets debt.

We provide access through multiple vehicles, including separately managed accounts, collective investment trusts, mutual funds, and Luxembourg-domiciled UCITS funds.

Global Equity

U.S. Growth and Core Equity

U.S. Value Equity

Emerging Markets Debt

Connecting Clients to Opportunities

Our investment teams are focused on active management across a wide range of strategies: global equity, growth and core equity, value equity, and emerging markets debt.

We offer a range of vehicles, including separately managed accounts, collective investment trusts, mutual funds, and Luxembourg-domiciled UCITS funds.

Global Equity

U.S. Growth and Core Equity

U.S. Value Equity

Emerging Markets Debt

A Trusted Partner

We serve consultants, foundations and endowments, public funds, corporations, Taft-Hartley plans, financial institutions, and financial advisors.

Download Taft-Hartley Plan Brochure

Institutional Client Breakdown

All data as of December 31, 2025. Numbers may not equal 100% due to rounding.

Why We Invest Shapes How We Invest

Culture is more than the ethos that characterizes our organization; it’s the engine that guides our practices. Our people are defined by their shared values and curiosity. Our approach is defined by teamwork; a disciplined, proven methodology; and technology-enhanced collaboration. Our purpose is defined by a focus on our clients and communities. But don’t take our word for it. See what culture means to our colleagues.

Our People

Our Approach

Our Purpose

Our History

Year	Milestones
1935	William McCormick Blair founds firm as Blair, Bonner & Company.
1941	The firm is renamed William Blair & Company and converted to a private partnership. The Chicago Historical Society becomes our first institutional client and is still with us today.
1946	Our first U.S. equity mutual fund launches.
1947	We register under the U.S. Investment Advisors Act of 1940.
1992	Our first international equity mutual fund launches and we begin investing in emerging markets through it.
1995	We develop a presence in William Blair’s Zurich office.
1998	We pioneered a new asset class with the launch of a small-mid-cap strategy.
2004	Our first Luxembourg-domiciled SICAV product launches.
2007	We develop a presence in William Blair’s London office.
2010	We launch our first collective investment trust (CIT).
2020	We lift out an emerging markets debt (EMD) team and launch hard, local, and blend strategies. We develop a presence in Singapore.
2021	We expand our U.S. value equity team through the acquisition of Investment Counselors of Maryland (ICM) in July 2021.
2026	We have 28 institutional strategies, 18 mutual funds, 12 SICAV funds, and $71.7 billion in AUM.

As of 6/30/2026

Any investment or strategy mentioned herein may not be appropriate for every investor. There can be no assurance that investment objectives will be met. Products and services listed are available only to residents of this jurisdiction and may only be available to certain categories of investors. The information on this website does not constitute an offer for products or services, or a solicitation of an offer to any persons outside of this jurisdiction who are prohibited from receiving such information under applicable laws and regulations. Nothing on this webpage should be construed as advice and is therefore not a recommendation to buy or sell shares.

Please carefully consider the William Blair Funds’ investment objectives, risks, charges, and expenses before investing. This and other information is contained in the Funds’ prospectus and summary prospectus, which you may obtain by calling 1-800-742-7272. Read the prospectus and summary prospectus carefully before investing. Investing includes the risk of loss.

The William Blair Funds are distributed by William Blair & Company, L.L.C., member FINRA/SIPC.

The William Blair SICAV is a Luxembourg investment company with variable capital registered with the Commission de Surveillance du Secteur Financier (“CSSF”) which qualifies as an undertaking for collective investment in transferable securities (“UCITS”). The Management Company of the SICAV has appointed William Blair Investment Management, LLC as the investment manager for the fund.

Please carefully consider the investment objectives, risks, charges, and expenses of the William Blair SICAV. This and other important information is contained in the prospectus and Key Investor Information Document (KIID). Read these documents carefully before investing. The information contained on this website is not a substitute for those documents or for professional external advice.

William Blair Investment Management, LLC is an investment adviser registered with the U.S. Securities and Exchange Commission.

Issued in the United Kingdom by William Blair International, Ltd., authorized and regulated by the Financial Conduct Authority (FCA), and is only directed at and is only made available to persons falling within articles 19, 38, 47, and 49 of the Financial Services and Markets Act of 2000 (Financial Promotion) Order 2005 (all such persons being referred to as "relevant persons").

Issued in the European Economic Area (EEA) by William Blair B.V., authorized and supervised by the Dutch Authority for the Financial Markets (AFM) under license number 14006134 and also supervised by the Dutch Central Bank (DNB), registered at the Dutch Chamber of Commerce under number 82375682 and has its statutory seat in Amsterdam, the Netherlands. This material is only intended for eligible counterparties and professional clients.

Issued in Switzerland by William Blair Investment Services (Zurich) GmbH, Talstrasse 65, 8001 Zurich, Switzerland ("WBIS"). WBIS is engaged in the offering of collective investment schemes and renders further, non-regulated services in the financial sector. WBIS is affiliated with FINOS Finanzomubdsstelle Schweiz, a recognized ombudsman office where clients may initiate mediation proceedings pursuant to articles 74 et seq. of the Swiss Financial Services Act ("FinSA"). The client advisers of WBIS are registered with regservices.ch by BX Swiss AG, a client adviser registration body authorized by the Swiss Financial Market Supervisory Authority ("FINMA"). WBIS is not supervised by FINMA or any other supervisory authority or self-regulatory organization. This material is only intended for institutional and professional clients pursuant to article 4(3) to (5) FinSA.

Issued in Australia by William Blair Investment Management, LLC (“William Blair”), which is exempt from the requirement to hold an Australian financial services license under Australia's Corporations Act 2001 (Cth). William Blair is registered as an investment advisor with the U.S. Securities and Exchange Commission (“SEC”) and regulated by the SEC under the U.S. Investment Advisers Act of 1940, which differs from Australian laws. This material is intended only for wholesale clients.

Issued in Singapore by William Blair International (Singapore) Pte. Ltd. (Registration Number 201943312R), which is regulated by the Monetary Authority of Singapore under a Capital Markets Services License to conduct fund management activities. This material is intended only for institutional investors and may not be distributed to retail investors.

Issued in Canada by William Blair Investment Management, LLC, which relies on the international adviser exemption, pursuant to section 8.26 of National Instrument 31-103 in Canada.

Investments

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Who We Are

Active Is More Than Just an Investment Approach

$71.7 billion

29% of our AUM

26 of 79

29

26 years

10.0 years

A Recognized Workplace

Institutional Client Breakdown

Premier Global Partnership

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Investments

Insights

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Institutional Client Breakdown

Premier Global Partnership

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