William Blair Investment Management, LLC is an SEC registered investment adviser organized as a limited liability company with a primary office location in Chicago, IL. Its latest Form ADV filing, dated April 9, 2026, reports $65.6B in regulatory assets under management, 388 employees, 3 offices, and 682 accounts.
Assets Under Management
$65.6B
Employees
388
Offices
3 offices
Total Clients
682
Primary office
CHICAGO, IL
150 NORTH RIVERSIDE PLAZA, CHICAGO, IL, United States
Portfolio management for individuals and small businesses
Portfolio management for investment companies
Fee models offered
2 types reported
Asset based fees
Performance-based fees
Sources checked May 16, 2026
Client Coverage Demographics
Top client segmentWRAP CLIENTS represent 56.6% of total clients.
Top client categories% of clientsClients
1
WRAP CLIENTS
56.6%
386
2
Pension Plans
10.7%
73
3
Charitable
10.0%
68
4
Government
7.9%
54
5
Pooled Investment Vehicles
7.5%
51
Categories with <5 clients
Banking or thrift institutions<5 clients
Individuals (other than high net worth individuals)<5 clients
Regulatory Assets Under Management Breakdown
Total regulatory assets under management$65.6Bas of April 9, 2026
Discretionary100.0%
$65.6B
100% of total RAUM100.0%
Non-discretionary0.0%
$0
0% of total RAUM0.0%
All regulatory assets under management are discretionary.
Assets under management Growth by Quarter
Quarterly points use the latest ADV filing or SEC roster snapshot available in each quarter.
Total AUM$65.6B
Total Accounts682
10Y AUM Change+$8.6B (+15.0%)
Employee Growth by Quarter
Quarterly points use the latest ADV filing or SEC roster snapshot available in each quarter.
Total Employees388
Clients per Employee2:1
10Y Employee Change+36 (+10.2%)
* Metrics are based on the latest available data, including Form ADV filings, brochures, and relationship summaries pulled from the SEC IAPD, and may be subject to change. Learn what is included in the Rialytix data. Please refer to the firm's official disclosures for the most accurate information using their CRD number. This is not investment advice.