William Blair & Company L.L.C. 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 March 31, 2026, reports $64.3B in regulatory assets under management, 492 employees, 11 offices, and 39,781 accounts.
Assets Under Management
$64.3B
Employees
492
Offices
11 offices
Total Clients
38,171
Primary office
CHICAGO, IL
150 NORTH RIVERSIDE PLAZA, CHICAGO, IL, United States
Top client segmentIndividuals represent 68.7% of total clients.
Top client categories% of clientsClients
1
Individuals
68.7%
26,242
2
HNWI
23.7%
9,054
3
Corporations
3.5%
1,333
4
Other Advisers
3.0%
1,146
5
Pension Plans
1.0%
364
Additional categories (<0.1%)
Pooled Investment Vehicles<5 clients
Regulatory Assets Under Management Breakdown
Total regulatory assets under management$64.3Bas of March 31, 2026
Discretionary90.3%
$58.1B
90% of total RAUM90.3%
Non-discretionary9.7%
$6.2B
10% of total RAUM9.7%
Regulatory assets under management are split between discretionary and non-discretionary assets.
Assets under management Growth by Quarter
Quarterly points use the latest ADV filing or SEC roster snapshot available in each quarter.
Latest AUM$64.3B
Total Accounts39,781
10Y AUM Change+$48.1B (+296.4%)
Employee Growth by Quarter
Quarterly points use the latest ADV filing or SEC roster snapshot available in each quarter.
Total Employees492
Clients per Employee78:1
10Y Employee Change+277 (+128.8%)
* 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.