No commissions, no ads, no advice. This William Blair profile draws only on public records, each linked so you can confirm it yourself.
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Check the SEC adviser record. Open the SEC's IAPD record for William Blair (CRD #1252) and confirm its registration.
Read the filings. Review the Form ADV / Form CRS and any disclosure section linked from the IAPD page.
Confirm the entity. Match CRD #1252 / William Blair so you're reading the right firm.
The short answer: is William Blair a fiduciary?
Yes. William Blair is a fiduciary when it acts as your investment adviser, and with $64.3 billion in client assets it is among the larger SEC-registered investment advisers. Publicly, it files with the SEC as William Blair & Company, L.L.C. (CRD #1252). As of its latest Form ADV (filed March 31, 2026), the firm reported $64.3 billion in regulatory assets under management (a firm-reported figure). Its Form ADV (Item 5.E) lists how it is paid: a percentage of assets under management and fixed fees. Every line here traces to a public filing you can pull yourself in a few minutes.
Its Form ADV also reports that the firm itself is registered as a broker-dealer, and brokerage accounts fall under Regulation Best Interest instead. Ask which capacity covers each of your accounts. The firm must tell you.
What "fiduciary" means: a fiduciary is legally bound to place a client's interests above its own. (More on fiduciary duty)
William Blair at a glance
✅ Verified from public filings, last checked October 5, 2026. William Blair (SEC CRD #1252) is a fiduciary when acting as your adviser, on an advisory-fee basis, with $64.3 billion in regulatory assets under management. Every figure below links to its primary source.
What | William Blair | Source |
|---|---|---|
SEC CRD | #1252 | |
Registration | Investment adviser and broker-dealer | |
Registered since | December 24, 1947 (SEC) | |
Fiduciary? | Yes, when acting as your adviser | |
Fee model | Advisory fees (no commissions reported in Item 5.E) | Form ADV Item 5.E |
How it's paid | A percentage of assets under management and fixed fees | Form ADV Item 5.E |
Regulatory Assets Under Management | $64.3 billion (Form ADV filed March 31, 2026) | |
Client accounts | 39,781 (38,800 discretionary) | |
Employees | 492 (231 in advisory roles) | |
Ownership | Parent-owned | |
Disclosures | Form ADV answers Yes to one or more disciplinary questions. Read them on IAPD | |
HQ | Chicago, IL |
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William Blair fees: what you'll pay
How William Blair gets paid is the story behind what you pay. Here's the structure. William Blair charges advisory fees: its Form ADV (Item 5.E) reports no commissions for its advisory services. Its filing also reports broker-dealer, insurance or other sales activity by the firm or a related company, business that can be paid by commissions. Ask how each part of the relationship is paid. The details are in its Form ADV Part 2A.
Advisory fees are what clients pay the adviser directly. Commissions earned through a related broker-dealer or insurance business are a separate source of pay.
Who owns William Blair, and what conflicts does it disclose?
Who stands behind William Blair is documented in its SEC filings, not left to guesswork. William Blair is owned by WBC Holdings, L.P., as listed in Schedule A of its Form ADV. (Form ADV Schedule A)
Its Form ADV Part 2A describes the firm's conflicts of interest, including how it and its advisers are paid.
William Blair SEC record: disclosures
To check William Blair's regulatory record, start with the firm's own filings. William Blair's Form ADV answers Yes to one or more disciplinary-history questions. A disclosure can be a regulatory, civil or criminal matter involving the firm or a related person. Read each item in context on IAPD before drawing conclusions. Whatever William Blair disclosures exist live on the public record. Read them there, in context, rather than secondhand.
On the record, the firm has been registered with the SEC since December 24, 1947, makes notice filings in 53 jurisdictions, and reports 492 employees, 231 of them in investment advisory roles. If you're asking "is William Blair legit?", start with registration: a public CRD and filings anyone can pull. That confirms it's a real, regulated adviser. Whether it's right for you is a separate question.
Reading William Blair reviews against the public record
Star ratings and client comments describe what working with a firm felt like. They usually don't show what the firm reports to regulators. Before you weigh William Blair reviews, check three things this profile takes from the public record. First, how the firm is paid: it reports advisory fees and no commissions, but it has a broker-dealer or insurance connection. Second, who owns it and what conflicts it discloses. Third, whether its Form ADV reports any disciplinary history. Read reviews alongside the record, not instead of it.
How to verify William Blair yourself
To check every line yourself, follow these three steps:
SEC adviser record (IAPD): https://adviserinfo.sec.gov/firm/summary/1252.
Form ADV / CRS: linked from the IAPD page.
Confirm the entity: match William Blair (CRD #1252) so you're reading the right firm.
What William Blair does and who it serves
On its Form ADV, William Blair reports providing financial planning, portfolio management for individuals and small businesses, portfolio management (pooled vehicles), portfolio management for businesses and institutions, and selection of other advisers.
It reports providing financial planning to about 2,700 clients in its last fiscal year (Form ADV Item 5.H), a count the form keeps separate from the client totals below.
Its Form ADV (Item 5.D) breaks its clients down by type, about 38,171 in all:
Client type | Clients | Assets managed |
|---|---|---|
Individuals | 26,242 | $7.33 billion |
High-net-worth individuals | 9,054 | $45.35 billion |
Pooled investment vehicles | 1 | $5.6 million |
Pension and profit-sharing plans | 364 | $379.1 million |
Charities | 31 | $1.77 billion |
Other investment advisers | 1,146 | $1.39 billion |
Corporations or other businesses | 1,333 | $8.06 billion |
It reports 39,781 client accounts, 38,800 discretionary (the firm can trade without seeking your approval first) and 981 non-discretionary (Item 5.F). Its main office is in Chicago, IL.
It reports that it or a related person has custody of certain client assets, which brings extra safeguards such as surprise examinations. The specifics are in its Form ADV.
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Vetting the firm is quick. Seeing your whole financial picture is the part that pays off.
Confirming William Blair is registered takes a few minutes. Even a seasoned advisor works from what reaches their desk, and that's rarely the whole picture. A rollover left behind or a partner's accounts often arrive separately, in clashing formats. This is where Truthifi comes in.
How Truthifi can help
Truthifi links your accounts read-only and shows what you own, how it's allocated, how it's performing and where the risk sits, including single-stock exposure, returns next to a benchmark, a fee breakdown of the fees on each account, by type, and your Truthifi Score. You can share the accounts you choose with your advisor at William Blair.
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Ask AI about your William Blair accounts
Once your accounts are connected read-only, you can ask in plain English:
"What do I own across my William Blair accounts and everything else, and how is it allocated?"
"What am I really paying in fees across all of these accounts?"
Try it with Truthifi: start for free at app.truthifi.com and run a Monitoring Checkup (limits apply).
No commissions, no ads, no advice: Truthifi is not an investment adviser and doesn't give investment, tax or legal advice. Its access to your bank and brokerage accounts is read-only. Start free (limits apply). Monitoring Checkup is free. Link up to 10 connections. Plans and limits are on the pricing page → truthifi.com.
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FAQ
Is William Blair a fiduciary? Yes, when acting as your adviser. Its Form ADV reports that it is also a broker-dealer, and brokerage accounts fall under Regulation Best Interest instead. Ask which capacity covers each of your accounts.
Is William Blair fee-only? Not necessarily. Its Form ADV (Item 5.E) reports no commissions for advisory services, but the filing also reports broker-dealer, insurance or other sales activity by the firm or a related company, which can be paid differently. Ask how everyone you deal with is paid. The details are in its Form ADV Part 2A.
Who owns William Blair? William Blair is owned by WBC Holdings, L.P., as listed in Schedule A of its Form ADV.
Does William Blair have complaints or disclosures? Yes. Its Form ADV answers Yes to one or more disciplinary-history questions. Read each item on IAPD, in context. A disclosure is not by itself proof of current wrongdoing.
Is William Blair legit? William Blair is registered with the SEC (CRD #1252) and its filings are public on the SEC's IAPD site, which confirms it is a real, regulated firm. Registration doesn't tell you whether it's the right fit or what you'll pay, so read the fee and conflict sections of its Form ADV.
Can AI help me check whether I'm getting good value? Yes. Start free (limits apply): Monitoring Checkup is free and lets you link up to 10 connections. You can also connect an AI assistant you already use (such as Claude). On Monitoring or Monitoring Plus+ you can ask it, in plain English, about the fees on each of your accounts. Truthifi is not an investment adviser and doesn't give investment, tax or legal advice.
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About this profile
Truthifi built this profile from the firm's own SEC filings (Form ADV and, where filed, Form CRS). Every page is reviewed by the Truthifi Team before publishing. The Truthifi advisor fact packs are an ongoing series checking U.S. investment advisers against their public filings, one firm at a time.
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A note on sources. The facts on this page come from publicly available documents, William Blair's SEC and FINRA filings, each linked inline so you can verify it yourself (SEC data current as of October 5, 2026). This is general information, not financial or legal advice, and Truthifi is not affiliated with William Blair. Regulatory records change, so always confirm against the official sources linked above. Spot something that should be corrected? Email us at support@truthifi.com.
Disclaimer: This article is for educational purposes only and does not constitute financial, tax, or legal advice. It should not be construed as a personalized recommendation regarding any investment, financial advisor, or financial product. All calculations use hypothetical scenarios and historical return assumptions; actual results will vary. Past performance does not guarantee future results. Consult a qualified financial professional for guidance specific to your situation. Truthifi is an investment monitoring platform — not a financial advisor, broker-dealer, or tax professional. Truthifi does not manage assets, recommend investments, sell financial products, or provide personalized financial advice. Truthifi earns no revenue from advisor referrals, product commissions, or AUM fees. Statistics and data cited reflect publicly available sources current as of the article’s publication date. Sources are linked throughout.