WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC — 13F Holdings & Portfolio
CIK 1644956 · latest 13F-HR filed 2026-11-06
WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC manages $30.83B in 13F-reported U.S. long-equity assets across 399 reported positions as of its 2026-09-30 13F-HR filing. Its largest disclosed positions are TSM (6.79%), NVDA (6.02%), GOOGL (4.03%). Quarter over quarter (versus its 2026-06-30 filing) the fund opened 46 new positions and exited 50; 89 existing positions rose in reported value and 221 fell.
AUM is the long-equity portion reported on Form 13F-HR. Excludes short positions, cash, foreign holdings, and non-13F assets. For informational purposes only — not investment advice.
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AUM
$30.83B
Long-equity book
Holdings
399
Distinct positions
Period
2026-09-30
Filed 2026-11-06
Q/Q Activity
+46 / −50 / ↑89 / ↓221
vs 2026-06-30
Portfolio charts
Latest quarter's book, what changed, and how the portfolio has evolved across filings.
Portfolio map
Q3 26TSM6.8% · -7%NVDA6.0% · -6%GOOGL4.0% · +13%AAPL3.3% · -7%MSFT2.8% · -16%AVGO2.3% · -4%META1.9% · -15%AMD1.6% · +3%MA1.3% · -23%P1.1% · -26%AMZN1.1% · -33%AMAT1.0% · +22%TWST0.9% · -33%CG0.9% · +15%GE0.9% · +8%BAP0.9% · +12%SNOW0.9% · -13%APH0.8% · +101%STX0.8% · +45%MLI0.8% · +105%FFIV0.8% · -7%TEVA0.8% · -7%RGEN0.8% · +58%MU0.8% · +1496%ARGX0.8% · -6%CRWD0.8% · +216%DT0.7% · +0%BWA0.7% · -2%PRMB0.7% · -2%ESTC0.7% · newTLN0.7% · +36%A0.7% · -5%LIN0.7% · -14%ONTO0.7% · -2%ITUB0.6% · -25%HALO0.6% · -36%UNH0.6% · -7%NOW0.6% · -15%KRYS0.6% · -9%EG0.6% · -2%MDGL0.6% · +4%MANH0.5% · +26%APPF0.5% · +16%GH0.5% · -28%VSH0.5% · +248%CW0.5% · -4%COST0.5% · -10%IDXX0.5% · +3%CNQ0.5% · -8%AKAM0.5% · -5%LOPE0.5% · -2%NVT0.5% · -17%HQY0.5% · -2%TRU0.5% · -7%WST0.5% · -4%TXN0.5% · +4%CCJ0.5% · -10%DIOD0.5% · -11%LSCC0.5% · -2%TTE0.5% · -8%
Box size = position value; colour = change in share count vs the prior quarter (green added, red trimmed, blue new). Rows split across managers or share classes are combined. Click a box for the stock.
Sector mix
% of 13F valueSectors from each company's SIC code; funds and ETFs grouped separately.
Biggest buys and sells
Q2 26 → Q3 26Estimated from the change in shares held × the quarter-end price, so price moves alone don't count as buying. New and exited positions are included.
13F assets and positions
4 quartersTotal reported 13F value (bars) and number of positions (line) each quarter. Value changes include market moves.
Top positions over time
reported valueThe eight largest current positions, valued at each quarter end.
Concentration
top 10 = 31%Cumulative share of the portfolio held in the largest N positions.
Firm Profile & Key People
As of the firm’s regulatory filing dated Apr 9, 2026.
Assets Under Management
$65.60B
Discretionary
$65.60B
Employees
388
Accounts
682
Address
150 NORTH RIVERSIDE PLAZA
CHICAGO, IL 60606-1598
CHICAGO, IL 60606-1598
Phone
(312) 236-1600
This firm reports 3 disclosure items on its registration.
| Name | Title / Status | Ownership | Type |
|---|---|---|---|
| ANDERSON, LISA, DAWN Control | DIRECTOR OF OPERATIONS since Dec 2017 | Less than 5% | Individual |
| CITARDI, CISSIE Control | GENERAL COUNSEL, EXECUTIVE COMMITTEE MEMBER since Jan 2021 | Less than 5% | Individual |
| DEVORE, RYAN, JACOB Control | EXECUTIVE COMMITTEE MEMBER since Nov 2017 | Less than 5% | Individual |
| GLEDHILL, BRENT, WALKER Control | PRESIDENT, CHIEF EXECUTIVE OFFICER, EXECUTIVE COMMITTEE MEMBER since Oct 2014 | Less than 5% | Individual |
| KENDALL, ROBERT, DANIEL Control | GLOBAL HEAD OF INVESTMENT MANAGEMENT, EXECUTIVE COMMITTEE MEMBER since Jul 2025 | Less than 5% | Individual |
| MARTINS, TELMO, R Control | CHIEF COMPLIANCE OFFICER since Jan 2026 | Less than 5% | Individual |
| MCLAUGHLIN, SCOTT, THOMAS Control | EXECUTIVE COMMITTEE MEMBER since Jan 2024 | Less than 5% | Individual |
| SATTERFIELD, BETH, A Control | CHIEF OPERATING OFFICER, EXECUTIVE COMMITTEE MEMBER since Jan 2023 | Less than 5% | Individual |
| TOLE, STEVEN, ROBERT Control | EXECUTIVE COMMITTEE MEMBER since Jan 2025 | Less than 5% | Individual |
| TRIMBERGER, MICHAEL, WILLIAM Control | CHIEF FINANCIAL OFFICER, EXECUTIVE COMMITTEE MEMBER since Jul 2023 | Less than 5% | Individual |
| WBC HOLDINGS, L.P. Control | HOLDING COMPANY since Oct 2014 | 75% or more | Domestic Entity |
| ZIMMER, MATTHEW, MONTGOMERY Control | EXECUTIVE COMMITTEE MEMBER since Feb 2022 | Less than 5% | Individual |
| WBC GP L.L.C. Control Indirect owner via WBC HOLDINGS, L.P. | GENERAL PARTNER since Oct 2014 | General partner, trustee or manager | Domestic Entity |
Ownership & leadership changes · 17 filings with changes since Nov 18, 2014
From the firm’s regulatory filings, newest first. Dates are filing dates: a filing that no longer lists someone does not say when they left.
Feb 3, 2026 filing
- No longer listedDUWA, ROBERT, J · EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person · listed since Jan 2024
- No longer listedQUINN, MICHAEL, PATRICK · EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person · listed since Jan 2024
- ChangedKENDALL, ROBERT, DANIEL · title GLOBAL HEAD OF INVESTMENT MANAGEMENT → GLOBAL HEAD OF INVESTMENT MANAGEMENT, EXECUTIVE COMMITTEE MEMBER
- ChangedTRIMBERGER, MICHAEL, WILLIAM · title CHIEF FINANCIAL OFFICER → CHIEF FINANCIAL OFFICER, EXECUTIVE COMMITTEE MEMBER
Jan 2, 2026 filing
- No longer listedRANDALL, WALTER, RAMSAY · CHIEF COMPLIANCE OFFICER · Less than 5% · control person · listed since Oct 2014
- AddedMARTINS, TELMO, R · CHIEF COMPLIANCE OFFICER · Less than 5% · control person
Aug 7, 2025 filing
- No longer listedBRAMING, STEPHANIE, GRIESER · EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person · listed since Oct 2017
Jul 16, 2025 filing
- AddedKENDALL, ROBERT, DANIEL · GLOBAL HEAD OF INVESTMENT MANAGEMENT · Less than 5% · control person
- ChangedBRAMING, STEPHANIE, GRIESER · title GLOBAL HEAD OF INVESTMENT MANAGEMENT, EXECUTIVE COMMITTEE MEMBER → EXECUTIVE COMMITTEE MEMBER
Feb 5, 2025 filing
- ChangedTOLE, STEVEN, ROBERT · now a control person
Jan 30, 2025 filing
- No longer listedDALRYMPLE, PETER, PLENK · EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person · listed since Feb 2022
- No longer listedSHARMA, ANURAG · MANAGING DIRECTOR, EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person · listed since Jan 2023
- AddedTOLE, STEVEN, ROBERT · EXECUTIVE COMMITTEE MEMBER · Less than 5%
Jan 24, 2024 filing
- AddedDUWA, ROBERT, J · EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person
- AddedMCLAUGHLIN, SCOTT, THOMAS · EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person
- AddedQUINN, MICHAEL, PATRICK · EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person
Jul 14, 2023 filing
- No longer listedZINDEL, JON, WALTER · CHIEF FINANCIAL OFFICER, EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person · listed since Oct 2014
- AddedTRIMBERGER, MICHAEL, WILLIAM · CHIEF FINANCIAL OFFICER · Less than 5% · control person
Mar 29, 2023 filing
- ChangedBRAMING, STEPHANIE, GRIESER · title EXECUTIVE COMMITTEE MEMBER → GLOBAL HEAD OF INVESTMENT MANAGEMENT, EXECUTIVE COMMITTEE MEMBER
Jan 19, 2023 filing
- No longer listedETTELSON, JOHN, ROGER · CHAIRMAN, EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person · listed since Oct 2014
- AddedSATTERFIELD, BETH, A · CHIEF OPERATING OFFICER, EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person
- AddedSHARMA, ANURAG · MANAGING DIRECTOR, EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person
- ChangedGLEDHILL, BRENT, WALKER · title PRESIDENT, CEO, EXECUTIVE COMMITTEE MEMBER → PRESIDENT, CHIEF EXECUTIVE OFFICER, EXECUTIVE COMMITTEE MEMBER
Older changes (8 more filings)
Feb 3, 2022 filing
- No longer listedCOOLIDGE, EDGAR, DAVID · VICE CHAIRMAN · Less than 5% · control person · listed since Oct 2014
- No longer listedMOORE, JOHN, CARROLL · EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person · listed since Oct 2014
- AddedDALRYMPLE, PETER, PLENK · EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person
- AddedZIMMER, MATTHEW, MONTGOMERY · EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person
- ChangedCITARDI, CISSIE · title GENERAL COUNSEL → GENERAL COUNSEL, EXECUTIVE COMMITTEE MEMBER
- ChangedETTELSON, JOHN, ROGER · title PRESIDENT, CEO, EXECUTIVE COMMITTEE MEMBER → CHAIRMAN, EXECUTIVE COMMITTEE MEMBER
- ChangedGLEDHILL, BRENT, WALKER · title EXECUTIVE COMMITTEE MEMBER → PRESIDENT, CEO, EXECUTIVE COMMITTEE MEMBER
Jan 19, 2021 filing
- No longer listedSIMON, ARTHUR, JOSEPH · GENERAL COUNSEL, EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person · listed since Oct 2014
- AddedCITARDI, CISSIE · GENERAL COUNSEL · Less than 5% · control person
Jan 2, 2020 filing
- No longer listedURBINA, JEFFREY, ALAN · EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person · listed since Oct 2014
Jan 31, 2018 filing
- No longer listedSMIRL, RICHARD, WILLIAM · CHIEF OPERATING OFFICER · Less than 5% · control person · listed since Oct 2014
- AddedANDERSON, LISA, DAWN · DIRECTOR OF OPERATIONS · Less than 5% · control person
Nov 9, 2017 filing
- AddedBRAMING, STEPHANIE, GRIESER · EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person
- AddedDEVORE, RYAN, JACOB · EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person
Sep 6, 2017 filing
- No longer listedSEITZ, MICHELLE, RENAE · EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person · listed since Oct 2014
Mar 30, 2016 filing
- No longer listedKIPHART, RICHARD, PAUL · EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person · listed since Oct 2014
Nov 18, 2014 filing (earliest on record)
- ListedCOOLIDGE, EDGAR, DAVID · VICE CHAIRMAN · Less than 5% · control person
- ListedETTELSON, JOHN, ROGER · PRESIDENT, CEO, EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person
- ListedGLEDHILL, BRENT, WALKER · EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person
- ListedKIPHART, RICHARD, PAUL · EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person
- ListedMOORE, JOHN, CARROLL · EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person
- ListedRANDALL, WALTER, RAMSAY · CHIEF COMPLIANCE OFFICER · Less than 5% · control person
- ListedSEITZ, MICHELLE, RENAE · EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person
- ListedSIMON, ARTHUR, JOSEPH · GENERAL COUNSEL, EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person
- ListedSMIRL, RICHARD, WILLIAM · CHIEF OPERATING OFFICER · Less than 5% · control person
- ListedURBINA, JEFFREY, ALAN · EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person
- ListedWBC GP L.L.C. · GENERAL PARTNER · General partner, trustee or manager · indirect via WBC HOLDINGS, L.P. · control person
- ListedWBC HOLDINGS, L.P. · HOLDING COMPANY · 75% or more · control person
- ListedZINDEL, JON, WALTER · CHIEF FINANCIAL OFFICER, EXECUTIVE COMMITTEE MEMBER · Less than 5% · control person
Quarter-over-quarter changes
Changes in reported position value vs the prior 13F, so price moves count too, not just shares bought or sold.
Top Adds (vs prior quarter)
- MICRON TECHNOLOGY INC$222.8M +1372.7%
- NVIDIA CORPORATION$134.7M +7.8%
- REPLIGEN CORP$131.4M +122.2%
- MICROSOFT CORP$113.6M +14.9%
- ALPHABET INC$101.1M +8.9%
Top Trims
- TAIWAN SEMICONDUCTOR MANUFAC-$265.2M -11.3%
- ASTRAZENECA PLC-$192.4M -67.9%
- POWER INTEGRATIONS INC-$188.7M -94.6%
- AMAZON COM INC-$141.5M -29.9%
- ALIGNMENT HEALTHCARE INC-$133.8M -72.4%
New Positions
- TEVA PHARMACEUTICAL INDS LTD$242.3M
- ELASTIC N V$212.3M
- MOBILITY GLOBAL INC$90.7M
- PROCORE TECHNOLOGIES INC$86.9M
- SOMNIGROUP INTERNATIONAL INC$70.0M
Exited Positions
- TEVA PHARMACEUTICAL INDS LTD$223.4M
- THE BALDWIN INSURANCE GRP IN$179.0M
- SYNAPTICS INC$154.0M
- SHARKNINJA INC$150.3M
- GARRETT MOTION INC$117.1M
WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC Holdings (2026-09-30)
Rows tagged Call or Put are options positions, not stock. Per SEC Form 13F-HR, Value shows the notional value of the underlying (shares covered × underlying price), not the option premium. Shares is the number of underlying shares covered (divide by 100 for contract count).
| # | Issuer | Symbol | CUSIP | Value | Weight | Shares | Type |
|---|---|---|---|---|---|---|---|
| 1 | TAIWAN SEMICONDUCTOR MANUFAC | TSM | 874039100 | $2.09B | 6.79% | 4,586,962 | SH |
| 2 | NVIDIA CORPORATION | NVDA | 67066G104 | $1.86B | 6.02% | 8,123,638 | SH |
| 3 | ALPHABET INC | GOOGL | 02079K305 | $1.24B | 4.03% | 3,608,059 | SH |
| 4 | APPLE INC | AAPL | 037833100 | $1.01B | 3.27% | 3,022,828 | SH |
| 5 | MICROSOFT CORP | MSFT | 594918104 | $877.8M | 2.85% | 1,711,417 | SH |
| 6 | BROADCOM INC | AVGO | 11135F101 | $696.5M | 2.26% | 1,983,340 | SH |
| 7 | META PLATFORMS INC | META | 30303M102 | $585.1M | 1.90% | 806,777 | SH |
| 8 | ADVANCED MICRO DEVICES INC | AMD | 007903107 | $479.1M | 1.55% | 783,197 | SH |
| 9 | MASTERCARD INCORPORATED | MA | 57636Q104 | $390.2M | 1.27% | 707,647 | SH |
| 10 | EVERPURE INC | P | 74624M102 | $333.4M | 1.08% | 2,549,694 | SH |
| 11 | AMAZON COM INC | AMZN | 023135106 | $332.1M | 1.08% | 1,332,803 | SH |
| 12 | APPLIED MATLS INC | AMAT | 038222105 | $310.1M | 1.01% | 606,347 | SH |
| 13 | TWIST BIOSCIENCE CORP | TWST | 90184D100 | $281.0M | 0.91% | 1,454,117 | SH |
| 14 | CARLYLE GROUP INC | CG | 14316J108 | $270.5M | 0.88% | 6,821,563 | SH |
| 15 | GE AEROSPACE | GE | 369604301 | $267.0M | 0.87% | 854,907 | SH |
| 16 | CREDICORP LTD | BAP | G2519Y108 | $265.7M | 0.86% | 699,385 | SH |
| 17 | SNOWFLAKE INC | SNOW | 833445109 | $265.3M | 0.86% | 781,249 | SH |
| 18 | AMPHENOL CORP | APH | 032095101 | $260.3M | 0.84% | 3,087,928 | SH |
| 19 | SEAGATE TECHNOLOGY HLDNGS PL | STX | G7997R103 | $255.5M | 0.83% | 276,990 | SH |
| 20 | MUELLER INDS INC | MLI | 624756102 | $246.8M | 0.80% | 4,072,710 | SH |
| 21 | F5 INC | FFIV | 315616102 | $243.5M | 0.79% | 546,951 | SH |
| 22 | TEVA PHARMACEUTICAL INDS LTD | TEVA | M8769Q102 | $242.3M | 0.79% | 6,118,972 | SH |
| 23 | REPLIGEN CORP | RGEN | 759916109 | $239.0M | 0.78% | 1,243,415 | SH |
| 24 | MICRON TECHNOLOGY INC | MU | 595112103 | $239.0M | 0.78% | 224,405 | SH |
| 25 | ARGENX SE | ARGX | 04016X101 | $237.2M | 0.77% | 247,401 | SH |
| 26 | CROWDSTRIKE HLDGS INC | CRWD | 22788C105 | $235.8M | 0.77% | 890,794 | SH |
| 27 | DYNATRACE INC | DT | 268150109 | $223.7M | 0.73% | 3,873,980 | SH |
| 28 | BORGWARNER INC | BWA | 099724106 | $223.2M | 0.72% | 3,712,405 | SH |
| 29 | PRIMO BRANDS CORPORATION | PRMB | 741623102 | $213.9M | 0.69% | 11,230,798 | SH |
| 30 | ELASTIC N V | ESTC | N14506104 | $212.3M | 0.69% | 2,315,469 | SH |
| 31 | TALEN ENERGY CORP | TLN | 87422Q109 | $211.9M | 0.69% | 677,759 | SH |
| 32 | AGILENT TECHNOLOGIES INC | A | 00846U101 | $211.2M | 0.69% | 1,225,480 | SH |
| 33 | LINDE PLC | LIN | G54950103 | $207.4M | 0.67% | 437,021 | SH |
| 34 | ONTO INNOVATION INC | ONTO | 683344105 | $200.8M | 0.65% | 652,188 | SH |
| 35 | ITAU UNIBANCO HLDG S A | ITUB | 465562106 | $181.4M | 0.59% | 21,269,537 | SH |
| 36 | HALOZYME THERAPEUTICS INC | HALO | 40637H109 | $178.5M | 0.58% | 1,616,472 | SH |
| 37 | UNITEDHEALTH GROUP INC | UNH | 91324P102 | $177.8M | 0.58% | 484,420 | SH |
| 38 | SERVICENOW INC | NOW | 81762P102 | $176.5M | 0.57% | 1,316,931 | SH |
| 39 | KRYSTAL BIOTECH INC | KRYS | 501147102 | $173.2M | 0.56% | 520,925 | SH |
| 40 | EVEREST GROUP LTD | EG | G3223R108 | $172.1M | 0.56% | 471,187 | SH |
| 41 | MADRIGAL PHARMACEUTICALS INC | MDGL | 558868105 | $169.9M | 0.55% | 337,035 | SH |
| 42 | MANHATTAN ASSOCIATES INC | MANH | 562750109 | $168.4M | 0.55% | 847,546 | SH |
| 43 | APPFOLIO INC | APPF | 03783C100 | $167.7M | 0.54% | 836,167 | SH |
| 44 | GUARDANT HEALTH INC | GH | 40131M109 | $167.3M | 0.54% | 937,974 | SH |
| 45 | VISHAY INTERTECHNOLOGY INC | VSH | 928298108 | $166.8M | 0.54% | 5,124,041 | SH |
| 46 | CURTISS WRIGHT CORP | CW | 231561101 | $166.3M | 0.54% | 305,868 | SH |
| 47 | COSTCO WHOLESALE CORPORATION | COST | 22160K105 | $163.5M | 0.53% | 179,618 | SH |
| 48 | IDEXX LABS INC | IDXX | 45168D104 | $159.8M | 0.52% | 306,107 | SH |
| 49 | CANADIAN NAT RES LTD MED TER | CNQ | 136385101 | $157.7M | 0.51% | 3,352,895 | SH |
| 50 | AKAMAI TECHNOLOGIES INC | AKAM | 00971T101 | $155.5M | 0.50% | 1,462,172 | SH |
Filing History
| Period | Filed | AUM | Holdings | Accession |
|---|---|---|---|---|
| 2026-09-30 | 2026-11-06 | $30.83B | 399 | 0001644956-26-000031 |
| 2026-06-30 | 2026-08-12 | $33.25B | 403 | 0001644956-26-000023 |
| 2026-03-31 | 2026-05-08 | $30.26B | 413 | 0001644956-26-000021 |
| 2025-12-31 | 2026-02-09 | $35.85B | 413 | 0001644956-26-000007 |
Filer Information
Address
150 NORTH RIVERSIDE PLAZACHICAGO, IL 60606
Phone
(312) 236-1600
Filing Manager
WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC
CHICAGO, IL
Signatory
Telmo Martins
Chief Compliance Officer