{
  "crd_number": 173961,
  "slug": "william-blair-investment-management-llc-chicago-il-173961",
  "primary_business_name": "WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC",
  "legal_name": "WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC",
  "dbas": [],
  "city": "Chicago",
  "state": "IL",
  "country": "United States",
  "cbsa_code": "16980",
  "metro": {
    "cbsa_code": "16980",
    "common_name": "Chicago",
    "msa_name": "Chicago-Naperville-Elgin, IL-IN",
    "path": "/advisors/il/chicago"
  },
  "registration_type": "sec",
  "registration_status": "Approved",
  "registration_date": "2014-12-04",
  "years_registered": 11,
  "period": "2026-10-01",
  "filing_date": "2026-04-09",
  "carried_forward": false,
  "raum_total": 65596131787.0,
  "raum_discretionary": 65596131787.0,
  "raum_non_discretionary": 0.0,
  "raum_band": "over_5b",
  "raum_band_label": "Over $5 billion",
  "total_employees": 388,
  "advisory_employees": 142,
  "client_count_bucket": "fewer_than_5_in_some_types",
  "clients_by_type": {
    "other": {
      "raum": 192736293.0,
      "count": 386,
      "description": "WRAP CLIENTS"
    },
    "charitable": {
      "raum": 2337130386.0,
      "count": 68
    },
    "individuals": {
      "raum": 0.0,
      "count": 0,
      "fewer_than_5": true
    },
    "banking_thrift": {
      "raum": 0.0,
      "count": 0,
      "fewer_than_5": true
    },
    "state_municipal": {
      "raum": 11930157073.0,
      "count": 54
    },
    "insurance_companies": {
      "raum": 23539301.0,
      "count": 4
    },
    "investment_companies": {
      "raum": 15843070677.0,
      "count": 29
    },
    "pension_profit_sharing": {
      "raum": 11851584002.0,
      "count": 73
    },
    "other_investment_advisers": {
      "raum": 320704865.0,
      "count": 1
    },
    "high_net_worth_individuals": {
      "raum": 18307395.0,
      "count": 2
    },
    "pooled_investment_vehicles": {
      "raum": 22147916513.0,
      "count": 51
    },
    "corporations_other_businesses": {
      "raum": 209518216.0,
      "count": 10
    },
    "business_development_companies": {
      "raum": 0.0,
      "count": 0
    },
    "sovereign_wealth_foreign_official": {
      "raum": 721467066.0,
      "count": 4
    }
  },
  "compensation_types": [
    "percentage_of_aum",
    "performance_based"
  ],
  "advisory_activities": [
    "portfolio_management_businesses_institutional",
    "portfolio_management_individuals",
    "portfolio_management_investment_companies",
    "portfolio_management_pooled_vehicles"
  ],
  "wrap_fee_participant": true,
  "disclosure_yes_count": 3,
  "states_registered": [
    "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"
  ],
  "websites": [
    "https://facebook.com/WilliamBlairIM",
    "https://im.williamblair.com",
    "https://instagram.com/williamblairim",
    "https://linkedin.com/showcase/william-blair-investment-management",
    "https://open.spotify.com/show/7cd8ano4miwMxS7VTsuaAL",
    "https://podcasts.apple.com/us/podcast/the-active-share/id1473139558",
    "https://tunein.com/podcasts/Business--Economics-Podcasts/The-Active-Share-p1234306",
    "https://twitter.com/williamblairim",
    "https://williamblair.com",
    "https://youtube.com/user/WilliamBlairInvMgmt"
  ],
  "iapd_url": "https://adviserinfo.sec.gov/firm/summary/173961",
  "disclosure_items": [
    {
      "item": "11.C(2)",
      "question": "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?"
    },
    {
      "item": "11.C(4)",
      "question": "Has the SEC or the CFTC ever entered an order against the firm or an advisory affiliate in connection with investment-related activity?"
    },
    {
      "item": "11.C(5)",
      "question": "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?"
    }
  ],
  "city_as_filed": "CHICAGO",
  "url": "https://advisorcensus.com/firm/william-blair-investment-management-llc-chicago-il-173961",
  "display_name": "William Blair Investment Management, LLC",
  "summary": "William Blair Investment Management, LLC is an SEC-registered investment advisory firm in Chicago, IL, registered since 2014, reporting over $5 billion in regulatory assets under management in its Form ADV filing dated April 9, 2026.",
  "citation": "AdvisorCensus. William Blair Investment Management, LLC (CRD 173961): Form ADV filing data as of October 2026.",
  "registration_type_label": "SEC-registered investment adviser",
  "compensation_labels": [
    "A percentage of assets under your management",
    "Performance-based fees"
  ],
  "advisory_activity_labels": [
    "Portfolio management for individuals and/or small businesses",
    "Portfolio management for investment companies (and business development companies)",
    "Portfolio management for pooled investment vehicles (other than investment companies)",
    "Portfolio management for businesses (other than small businesses) or institutional clients"
  ],
  "quick_answers": [
    {
      "q": "How is William Blair Investment Management, LLC compensated?",
      "a": "On its Form ADV (Item 5.E, October 2026), William Blair Investment Management, LLC reports these compensation arrangements: a percentage of assets under its management; performance-based fees. The amounts are in Item 5 of its Form ADV Part 2A brochure."
    },
    {
      "q": "Where is William Blair Investment Management, LLC located?",
      "a": "William Blair Investment Management, LLC's principal office is in Chicago, IL, according to its Form ADV; the May 2026 filing also lists 3 other offices (Schedule D, Section 1.F)."
    },
    {
      "q": "Is William Blair Investment Management, LLC registered with the SEC or a state?",
      "a": "William Blair Investment Management, LLC is an SEC-registered investment advisory firm, registered since 2014. Status as filed: Approved. CRD 173961."
    },
    {
      "q": "How much does William Blair Investment Management, LLC manage?",
      "a": "William Blair Investment Management, LLC reports $65,596,131,787 in regulatory assets under management in its Form ADV filing dated April 9, 2026 (100% discretionary)."
    },
    {
      "q": "How have William Blair Investment Management, LLC's assets and staff changed since 2021?",
      "a": "In the Form ADV data for William Blair Investment Management, LLC: Regulatory assets under management: $69,739,613,957 in the October 2021 data and $65,596,131,787 in the October 2026 data, down 6%. Total employees: 345 in October 2021 and 388 in October 2026. Assets under management move with markets as well as with clients coming and going."
    },
    {
      "q": "What types of clients does William Blair Investment Management, LLC serve?",
      "a": "By number of clients on Form ADV Item 5.D: other (386); pension and profit sharing plans (but not the plan participants or government pension plans) (73); charitable organizations (68)."
    },
    {
      "q": "Which custodians does William Blair Investment Management, LLC use?",
      "a": "William Blair Investment Management, LLC's most recent Form ADV filing (Schedule D, Section 5.K(3)) lists Bank of New York Mellon, State Street Bank and Trust Company and The Northern Trust Company as custodians holding 10% or more of its separately managed account assets."
    },
    {
      "q": "Does William Blair Investment Management, LLC report any disciplinary disclosures?",
      "a": "Reports 3 disclosure items on Form ADV Item 11: yes answers to 11.C(2) (SEC or CFTC finding of a violation), 11.C(4) (SEC or CFTC order), and 11.C(5) (SEC or CFTC civil money penalty or cease-and-desist order). 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/173961"
    },
    {
      "q": "What changed in William Blair Investment Management, LLC's recent Form ADV filings?",
      "a": "In the April 2026 filing data: Employees performing advisory functions went from 152 to 142."
    }
  ],
  "filing_history": [
    {
      "period": "2021-10-01",
      "regulatory_assets_under_management": 69739613957.0,
      "total_employees": 345,
      "filing_date": "2021-07-19"
    },
    {
      "period": "2022-10-01",
      "regulatory_assets_under_management": 79683544422.0,
      "total_employees": 389,
      "filing_date": "2022-09-15"
    },
    {
      "period": "2023-10-01",
      "regulatory_assets_under_management": 56044084183.0,
      "total_employees": 377,
      "filing_date": "2023-07-14"
    },
    {
      "period": "2024-10-01",
      "regulatory_assets_under_management": 67246025476.0,
      "total_employees": 372,
      "filing_date": "2024-03-28"
    },
    {
      "period": "2025-10-01",
      "regulatory_assets_under_management": 71590158244.0,
      "total_employees": 378,
      "filing_date": "2025-07-16"
    },
    {
      "period": "2026-10-01",
      "regulatory_assets_under_management": 65596131787.0,
      "total_employees": 388,
      "filing_date": "2026-04-09"
    }
  ],
  "recent_changes": [
    {
      "period": "2026-04-01",
      "period_label": "April 2026",
      "notes": [
        "Employees performing advisory functions went from 152 to 142."
      ]
    },
    {
      "period": "2026-03-01",
      "period_label": "March 2026",
      "notes": [
        "Updated its list of owners and control persons (Schedule A)."
      ]
    },
    {
      "period": "2026-02-01",
      "period_label": "February 2026",
      "notes": [
        "Updated its list of owners and control persons (Schedule A)."
      ]
    }
  ],
  "fees_from_brochure": null,
  "custodians": [
    {
      "name": "Bank of New York Mellon",
      "name_as_filed": "BANK OF NEW YORK MELLON",
      "affiliated": false
    },
    {
      "name": "State Street Bank and Trust Company",
      "name_as_filed": "STATE STREET BANK AND TRUST COMPANY",
      "affiliated": false
    },
    {
      "name": "The Northern Trust Company",
      "name_as_filed": "THE NORTHERN TRUST COMPANY",
      "affiliated": false
    }
  ],
  "custodians_note": "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.",
  "markdown_url": "https://advisorcensus.com/firm/william-blair-investment-management-llc-chicago-il-173961.md",
  "clients": [
    {
      "type": "individuals",
      "label": "Individuals (other than high net worth individuals)",
      "count": 0,
      "fewer_than_5": true,
      "raum": 0.0
    },
    {
      "type": "high_net_worth_individuals",
      "label": "High net worth individuals",
      "count": 2,
      "fewer_than_5": false,
      "raum": 18307395.0
    },
    {
      "type": "banking_thrift",
      "label": "Banking or thrift institutions",
      "count": 0,
      "fewer_than_5": true,
      "raum": 0.0
    },
    {
      "type": "investment_companies",
      "label": "Investment companies",
      "count": 29,
      "fewer_than_5": false,
      "raum": 15843070677.0
    },
    {
      "type": "business_development_companies",
      "label": "Business development companies",
      "count": 0,
      "fewer_than_5": false,
      "raum": 0.0
    },
    {
      "type": "pooled_investment_vehicles",
      "label": "Pooled investment vehicles (other than investment companies and business development companies)",
      "count": 51,
      "fewer_than_5": false,
      "raum": 22147916513.0
    },
    {
      "type": "pension_profit_sharing",
      "label": "Pension and profit sharing plans (but not the plan participants or government pension plans)",
      "count": 73,
      "fewer_than_5": false,
      "raum": 11851584002.0
    },
    {
      "type": "charitable",
      "label": "Charitable organizations",
      "count": 68,
      "fewer_than_5": false,
      "raum": 2337130386.0
    },
    {
      "type": "state_municipal",
      "label": "State or municipal government entities (including government pension plans)",
      "count": 54,
      "fewer_than_5": false,
      "raum": 11930157073.0
    },
    {
      "type": "other_investment_advisers",
      "label": "Other investment advisers",
      "count": 1,
      "fewer_than_5": false,
      "raum": 320704865.0
    },
    {
      "type": "insurance_companies",
      "label": "Insurance companies",
      "count": 4,
      "fewer_than_5": false,
      "raum": 23539301.0
    },
    {
      "type": "sovereign_wealth_foreign_official",
      "label": "Sovereign wealth funds and foreign official institutions",
      "count": 4,
      "fewer_than_5": false,
      "raum": 721467066.0
    },
    {
      "type": "corporations_other_businesses",
      "label": "Corporations or other businesses not listed above",
      "count": 10,
      "fewer_than_5": false,
      "raum": 209518216.0
    },
    {
      "type": "other",
      "label": "Other",
      "count": 386,
      "fewer_than_5": false,
      "raum": 192736293.0
    }
  ],
  "disclosure_line": "Reports 3 disclosure items on Form ADV Item 11.",
  "indexable": true,
  "suppressed": false,
  "claimed": false,
  "enhanced": false,
  "provided_by_the_firm": null,
  "source": {
    "name": "Form ADV",
    "as_of": "2026-10-01",
    "iapd_url": "https://adviserinfo.sec.gov/firm/summary/173961",
    "operator": "BH Monitor Services, LLC",
    "license": "https://creativecommons.org/licenses/by/4.0/",
    "credit": "AdvisorCensus (advisorcensus.com), from SEC Form ADV data"
  }
}