Data / Investment advisers / Illinois / William Blair & Company L.L.C.
William Blair & Company L.L.C., Chicago, IL: $64.3 billion AUM, SEC registered investment adviser
Updated November 7, 2026. Source: the SEC's Form ADV data files for investment advisers.
William Blair & Company L.L.C. is an SEC registered investment adviser with its main office in Chicago, Illinois and reports $64.3 billion in regulatory assets under management in its Form ADV filed October 16, 2026. Its clients include high net worth individuals, corporations and other businesses and individuals. It is paid through a percentage of assets under management and fixed fees. It advises 21 private funds.
The request: Watch William Blair & Company L.L.C. (CRD number 1252): each new Form ADV amendment, with AUM, clients and private funds. $10 of work on sign-up, no card.
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- Registration
- SEC registered investment adviser
- CRD number
- 1252
- SEC file number
- 801-688
- SEC status
- Approved, effective December 24, 1947
- Main office
- 150 North Riverside Plaza, Chicago, IL 60606
- Phone
- (312) 236-1600
- Regulatory AUM
- $64,284,844,374 in the Form ADV filed October 16, 2026
- Discretionary AUM
- $58,076,278,078
- Non discretionary AUM
- $6,208,566,296
- Accounts
- 39,781
- Employees
- 492, of which 231 give investment advice
- Form of organization
- Limited Liability Company
- Paid through
- a percentage of assets under management, fixed fees
- Private funds
- 21: 21 private equity funds
- Gross assets of private funds
- $114,739,896
- Other offices
- 11
- Form ADV Item 11 disclosures
- Reported: SEC or CFTC regulatory actions, other federal, state or foreign regulatory actions, self-regulatory organization actions
- Latest Form ADV filing
- October 16, 2026
- SEC record
- Investment Adviser Public Disclosure
Clients
Client types the adviser reports in Form ADV item 5.D, with the AUM it attributes to each.
| Client type | Clients | AUM |
|---|---|---|
| High net worth individuals | 9,054 | $45.35 billion |
| Corporations or other businesses | 1,333 | $8.06 billion |
| Individuals (other than high net worth individuals) | 26,242 | $7.33 billion |
| Charitable organizations | 31 | $1.77 billion |
| Other investment advisers | 1,146 | $1.39 billion |
| Pension and profit sharing plans | 364 | $379.1 million |
| Pooled investment vehicles | 1 | $5.6 million |
AUM in the SEC's monthly files
Each change in the AUM the adviser reported across the monthly SEC files held here, with the first file that shows the new value.
| First in the file of | AUM | Form ADV filed |
|---|---|---|
| April 1, 2026 | $64.28 billion | March 31, 2026 |
| December 1, 2025 | $58.33 billion | August 14, 2025 |
Other advisers in Chicago
| Adviser | City | AUM | Private funds | Source |
|---|---|---|---|---|
| Blue Owl Real Estate Capital LLC | Chicago | $67.88 billion | 54 | adviserinfo.sec.gov |
| CIBC Private Wealth Advisors, Inc. | Chicago | $67.84 billion | Not listed | adviserinfo.sec.gov |
| Harbor Capital Advisors, Inc. | Chicago | $67.64 billion | 1 | adviserinfo.sec.gov |
| Adams Street Partners, LLC | Chicago | $66.49 billion | 327 | adviserinfo.sec.gov |
| William Blair Investment Management, LLC | Chicago | $65.60 billion | 9 | adviserinfo.sec.gov |
| Towers Watson Investment Services, Inc. | Chicago | $62.67 billion | 11 | adviserinfo.sec.gov |
| Valor Equity Partners | Chicago | $59.32 billion | 54 | adviserinfo.sec.gov |
| BDT Capital Partners | Chicago | $51.52 billion | 45 | adviserinfo.sec.gov |
Also on SpecStream
- Investment advisers in Chicago, IL
- Investment advisers in Illinois
- Advisers with $10 billion to $100 billion in AUM
- Advisers serving high net worth individuals
- Advisers serving corporations and other businesses
- Advisers that manage private funds
- William Blair & Company L.L.C. on the SEC's adviser search
Public data published by the US Securities and Exchange Commission (US government work). Advisers report these values themselves in Form ADV, and neither the SEC nor the states approve or guarantee them. AUM is regulatory assets under management as the adviser reported it in Form ADV item 5.F, which can differ from the AUM a firm quotes elsewhere. Exempt reporting advisers do not report AUM. Office address, phone and website are the adviser's main office as filed; a firm that files its main office as a private residence shows no street address or phone. An Item 11 disclosure is a reported event, not a finding about the firm today. Details for each firm are on the SEC's Investment Adviser Public Disclosure site. This page uses SEC data and is not endorsed or certified by the SEC. Free to reuse with credit to SpecStream under CC BY 4.0. Spot a wrong value? Write to [email protected] with the link to this page.