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WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC
CRD 173961File 801-80640
APPROVED
Retail clients
Custody
Disclosure events
Filing as of Apr 9, 2026
Feed vintage Oct 1, 2026
Regulatory AUM
$65.60B
Top 10% of cohort (national)
Discretionary AUM
$65.60B
Clients
296
682 accounts
Employees
388
Top 10% of cohort in IL
Identity & registration
ADV Item 1- Organization form
- Limited Liability Company
- Firm type
- Registered
- SEC region
- CHRO
- Registration date
- Dec 4, 2014
- Principal office
- 150 NORTH RIVERSIDE PLAZA, CHICAGO, IL, 60606-1598
- Phone
- 312-236-1600
Assets & accounts
ADV Item 5F- Total regulatory AUM
- $65.60B
- Discretionary AUM
- $65.60B
- Non-discretionary AUM
- $0
- Discretionary accounts
- 682
- Non-discretionary accounts
- 0
- Total accounts
- 682
- AUM per client
- $221.6M
Clients by type
ADV Item 5D| Client type | Clients | AUM |
|---|---|---|
| Other | 10 | $209.5M |
| Non-U.S. persons | 4 | $721.5M |
| Insurance companies | 4 | $23.5M |
| Investment companies | 29 | $15.84B |
| Charitable organizations | 68 | $2.34B |
| Other investment advisers | 1 | $320.7M |
| High net worth individuals | 2 | $18.3M |
| Pooled investment vehicles | 51 | $22.15B |
| Banking or thrift institutions | Fewer than 5 | $0 |
| Pension and profit sharing plans | 73 | $11.85B |
| State or municipal government entities | 54 | $11.93B |
| Individuals (other than high net worth individuals) | Fewer than 5 | $0 |
Compensation & activities
ADV Items 5E, 5GCompensation
- Performance-based fees
- A percentage of assets under your management
Advisory activities
- Portfolio management for businesses
- Portfolio management for investment companies
- Portfolio management for pooled investment vehicles
- Portfolio management for individuals and/or small businesses
Custody
ADV Item 9- Firm Custody Cash
- Yes
- Firm Custody Assets
- Yes
- Firm Custody Clients
- Yes
- Firm Custody Securities
- Yes
- Related Person Custody Cash
- No
- Related Person Custody Assets
- No
- Related Person Custody Clients
- No
- Related Person Custody Securities
- Yes
Disclosure events
ADV Item 11- Q11
- Q11C2
- Q11C4
- Q11C5
Filed changes
| Date | Field | From | To | Change |
|---|---|---|---|---|
| Aug 17, 2026 | Clients | 682 | 296 | decreased by386 |
| Apr 1, 2026 | Employees | 378 | 388 | increased by10 |
| Apr 1, 2026 | Clients | 1,047 | 682 | decreased by365 |
| Apr 1, 2026 | AUM | $71,590,158,244 | $65,596,131,787 | decreased by$5,994,026,457 |
| Apr 1, 2026 | Accounts | 1,047 | 682 | decreased by365 |
| May 1, 2025 vs Oct 1, 2022 | Employees | 389 | 378 | decreased by11 |
| May 1, 2025 vs Oct 1, 2022 | Disclosures | No | Yes | |
| May 1, 2025 vs Oct 1, 2022 | Clients | 1,054 | 1,047 | decreased by7 |
| May 1, 2025 vs Oct 1, 2022 | AUM | $79,683,544,422 | $71,590,158,244 | decreased by$8,093,386,178 |
| May 1, 2025 vs Oct 1, 2022 | Accounts | 940 | 1,047 | increased by107 |
| Apr 1, 2022 | Employees | 345 | 389 | increased by44 |
| Apr 1, 2022 | Clients | 605 | 1,054 | increased by449 |
| Apr 1, 2022 | AUM | $69,739,613,957 | $79,683,544,422 | increased by$9,943,930,465 |
| Apr 1, 2022 | Accounts | 498 | 940 | increased by442 |
| Apr 1, 2021 | Registration | — | APPROVED |
On Form 5500, an adviser usually appears as a plan service provider (Schedule C), not the plan sponsor.
See plans that list “WILLIAM BLAIR” as a service provider on 5500mcp →Matched by name only — Form ADV and Form 5500 share no identifier, and names are searched loosely (“WILLIAM BLAIR” may also match similarly-named firms). Confirm identity against each filing.
Every value above is reproduced from this firm's Form ADV filing. Fields the firm left blank are shown as “Not reported” rather than filled in from other sources.