# William Blair & Company L.L.C.

> William Blair & Company L.L.C. is an SEC-registered investment advisory firm in Chicago, IL, registered since 1947, reporting over $5 billion in regulatory assets under management in its Form ADV filing dated March 31, 2026.

- CRD: 1252
- Filed as: WILLIAM BLAIR & COMPANY L.L.C.
- Registration: SEC-registered investment adviser (status as filed: Approved)
- Location: Chicago, IL
- Filing period: October 2026
- Form ADV filing dated: March 31, 2026
- SEC record (IAPD): https://adviserinfo.sec.gov/firm/summary/1252
- AdvisorCensus page: https://advisorcensus.com/firm/william-blair-and-company-l-l-c-chicago-il-1252

## Quick answers

**How is William Blair & Company L.L.C. compensated?**
On its Form ADV (Item 5.E, October 2026), William Blair & Company L.L.C. reports these compensation arrangements: a percentage of assets under its management; fixed fees (other than subscription fees).

**How much does William Blair & Company L.L.C. charge?**
Its Form ADV Part 2A brochure dated March 31, 2026 states: Asset-based fee: up to 2% of assets a year (the maximum the brochure states). Fees can differ by service and may be negotiable; the brochure is the complete statement.

**Where is William Blair & Company L.L.C. located?**
William Blair & Company L.L.C.'s principal office is in Chicago, IL, according to its Form ADV; the April 2026 filing also lists 11 other offices (Schedule D, Section 1.F).

**Is William Blair & Company L.L.C. registered with the SEC or a state?**
William Blair & Company L.L.C. is an SEC-registered investment advisory firm, registered since 1947. Status as filed: Approved. CRD 1252.

**How much does William Blair & Company L.L.C. manage?**
William Blair & Company L.L.C. reports $64,284,844,374 in regulatory assets under management in its Form ADV filing dated March 31, 2026 (90% discretionary).

**How have William Blair & Company L.L.C.'s assets and staff changed since 2021?**
In the Form ADV data for William Blair & Company L.L.C.: Regulatory assets under management: $42,225,714,120 in the October 2021 data and $64,284,844,374 in the October 2026 data, up 52%. Total employees: 303 in October 2021 and 492 in October 2026. Assets under management move with markets as well as with clients coming and going.

**What types of clients does William Blair & Company L.L.C. serve?**
By number of clients on Form ADV Item 5.D: individuals (other than high net worth individuals) (26,242); high net worth individuals (9,054); corporations or other businesses not listed above (1,333).

**Which custodians does William Blair & Company L.L.C. use?**
William Blair & Company L.L.C.'s most recent Form ADV filing (Schedule D, Section 5.K(3)) lists National Financial Services LLC as a custodian holding 10% or more of its separately managed account assets.

**Does William Blair & Company L.L.C. report any disciplinary disclosures?**
Reports 6 disclosure items on Form ADV Item 11: yes answers to 11.C(1) (SEC or CFTC finding of a false statement or omission), 11.C(2) (SEC or CFTC finding of a violation), 11.C(4) (SEC or CFTC order), 11.C(5) (SEC or CFTC civil money penalty or cease-and-desist order), 11.D(2) (another regulator's finding of a violation), and 11.E(2) (self-regulatory organization's finding of a rule violation). Each question covers the firm and its advisory affiliates, and one event can produce several yes answers. The detail of any item is on the firm's SEC record: https://adviserinfo.sec.gov/firm/summary/1252

**What changed in William Blair & Company L.L.C.'s recent Form ADV filings?**
In the April 2026 filing data: Employees performing advisory functions went from 201 to 231. Regulatory assets under management went from $58,329,726,421 to $64,284,844,374 (+10%). Added an office in Conshohocken, PA. Added an office in Fort Myers, FL. Added an office in Powell, OH. No longer lists an office in Radnor, PA. No longer lists an office in Wyncote, PA.

## From the Form ADV filing

### Compensation (Item 5.E)
- A percentage of assets under your management
- Fixed fees (other than subscription fees)

### Fees and minimums (Form ADV Part 2A brochure dated March 31, 2026)

- Asset-based fee: up to 2% of assets a year (the maximum the brochure states)

> We charge up to a 2.00% fee on all assets, subject to negotiation.

As stated in the firm's brochure. Fees can differ by service and may be negotiable.

### Custodians (Schedule D, Section 5.K(3))
- National Financial Services LLC

Custodians holding 10% or more of the firm's separately managed account assets, as filed on Form ADV (Schedule D, Section 5.K(3)). A custodian holds client assets; it does not endorse or supervise the firm. AdvisorCensus has no relationship with any custodian.

### Regulatory assets under management (Item 5.F)
- Total: $64,284,844,374
- Discretionary: $58,076,278,078
- Non-discretionary: $6,208,566,296

### Clients (Item 5.D)

| Client type | Clients | Assets |
| --- | --- | --- |
| Individuals (other than high net worth individuals) | 26,242 | $7,326,873,678 |
| High net worth individuals | 9,054 | $45,350,562,302 |
| Banking or thrift institutions | 0 | $0 |
| Investment companies | 0 | $0 |
| Business development companies | 0 | $0 |
| Pooled investment vehicles (other than investment companies and business development companies) | 1 | $5,616,826 |
| Pension and profit sharing plans (but not the plan participants or government pension plans) | 364 | $379,121,552 |
| Charitable organizations | 31 | $1,771,479,072 |
| State or municipal government entities (including government pension plans) | 0 | $0 |
| Other investment advisers | 1,146 | $1,393,987,774 |
| Insurance companies | 0 | $0 |
| Sovereign wealth funds and foreign official institutions | 0 | $0 |
| Corporations or other businesses not listed above | 1,333 | $8,057,203,170 |
| Other | 0 | $0 |

### Advisory services (Item 5.G)
- Financial planning services
- Portfolio management for individuals and/or small businesses
- Portfolio management for pooled investment vehicles (other than investment companies)
- Portfolio management for businesses (other than small businesses) or institutional clients
- Selection of other advisers (including private fund managers)
- Other

### Firm details
- Registered since: 1947 (78 years)
- Employees: 492 total, 231 performing advisory functions
- Wrap fee program participation: Yes
- States registered or notice-filed: AK, AL, AR, AZ, CA, CO, CT, DC, DE, FL, GA, HI, IA, ID, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MS, MT, NC, ND, NE, NH, NJ, NM, NV, NY, OH, OK, OR, PA, PR, RI, SC, SD, TN, TX, UT, VA, VI, VT, WA, WI, WV, WY
- Disclosures (Item 11): Reports 6 disclosure items on Form ADV Item 11.

### Item 11 questions answered yes
- 11.C(1): Has the SEC or the CFTC ever found that the firm or an advisory affiliate made a false statement or omission?
- 11.C(2): Has the SEC or the CFTC ever found that the firm or an advisory affiliate was involved in a violation of SEC or CFTC regulations or statutes?
- 11.C(4): Has the SEC or the CFTC ever entered an order against the firm or an advisory affiliate in connection with investment-related activity?
- 11.C(5): Has the SEC or the CFTC ever imposed a civil money penalty on the firm or an advisory affiliate, or ordered the firm or an advisory affiliate to cease and desist from an activity?
- 11.D(2): Has another federal regulator, a state regulator, or a foreign financial regulator ever found that the firm or an advisory affiliate was involved in a violation of investment-related regulations or statutes?
- 11.E(2): Has a self-regulatory organization or a commodities exchange ever found that the firm or an advisory affiliate was involved in a violation of its rules, other than a minor rule violation under a plan the SEC approved?

Each question covers the firm and its advisory affiliates: its current employees other than clerical staff, its officers, partners, and directors, and anyone who controls the firm or is controlled by it. One event can produce yes answers to several questions. SEC-registered advisers and exempt reporting advisers may leave out events more than ten years old, and may answer 11.A(2) and 11.B(2) for pending charges only. The detail of each yes answer is on the firm's SEC record: https://adviserinfo.sec.gov/firm/summary/1252

### Other offices (Schedule D, Section 1.F), as of the April 2026 filing
- Atlanta, GA
- Baltimore, MD
- Boston, MA
- Conshohocken, PA
- Denver, CO
- Fort Myers, FL
- Los Angeles, CA
- New York, NY
- Powell, OH
- San Francisco, CA
- Stamford, CT

### Websites listed on Form ADV (Item 1.I)
- [williamblair.com](https://williamblair.com)
- Facebook @WilliamBlairCo
- Instagram @williamblaircompany
- LinkedIn @william-blair-&-company
- LinkedIn @william-blair-private-wealth-management
- X @williamblair

## Assets and staff over time

| Data period | Regulatory assets under management | Employees | Filing dated |
| --- | --- | --- | --- |
| October 2021 | $42,225,714,120 | 303 | September 15, 2021 |
| October 2022 | $49,965,190,648 | 326 | September 26, 2022 |
| October 2023 | $41,721,600,830 | 459 | August 1, 2023 |
| October 2024 | $49,981,350,919 | 440 | May 14, 2024 |
| October 2025 | $58,329,726,421 | 469 | March 31, 2025 |
| October 2026 | $64,284,844,374 | 492 | March 31, 2026 |

Regulatory assets under management: $42,225,714,120 in the October 2021 data and $64,284,844,374 in the October 2026 data, up 52%.
Total employees: 303 in October 2021 and 492 in October 2026.

## Changes in the filing (last 12 months)

### April 2026
- Employees performing advisory functions went from 201 to 231.
- Regulatory assets under management went from $58,329,726,421 to $64,284,844,374 (+10%).
- Added an office in Conshohocken, PA.
- Added an office in Fort Myers, FL.
- Added an office in Powell, OH.
- No longer lists an office in Radnor, PA.
- No longer lists an office in Wyncote, PA.

### March 2026
- Updated its list of owners and control persons (Schedule A).

## Source

Form ADV as filed, October 2026. Values appear as filed. Cite as: AdvisorCensus. William Blair & Company L.L.C. (CRD 1252): Form ADV filing data as of October 2026.