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WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC — 13F Holdings & Portfolio

CIK 1644956 · latest 13F-HR filed 2026-08-12

Backtest portfolio

WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC manages $33.25B in 13F-reported U.S. long-equity assets across 403 reported positions as of its 2026-06-30 13F-HR filing. Its largest disclosed positions are TSM (7.09%), NVDA (5.17%), GOOGL (3.43%). Quarter over quarter (versus its 2026-03-31 filing) the fund opened 47 new positions, exited 57, added to 162, and trimmed 141.

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.

Filer Information
Address
150 NORTH RIVERSIDE PLAZA
CHICAGO, IL 60606
Phone
(312) 236-1600
Filing Manager
WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC
CHICAGO, IL
Signatory
Telmo Martins
Chief Compliance Officer
Loading holdings…
AUM

$33.25B

Long-equity book

Holdings

403

Distinct positions

Period

2026-06-30

Filed 2026-08-12

Q/Q Activity

+47 / −57 / ↑162 / ↓141

vs 2026-03-31

Firm Profile & Key People
Name Title / Status Ownership Type

Top Adds (vs prior quarter)

  • TAIWAN SEMICONDUCTOR MANUFAC$491.9M +26.4%
  • ALPHABET INC$420.1M +58.3%
  • APPLIED MATLS INC$348.1M +2914.7%
  • ADVANCED MICRO DEVICES INC$231.4M +109.1%
  • TEVA PHARMACEUTICAL INDS LTD$180.4M +420.1%
Show all 162 →

Top Trims

  • MICROSOFT CORP-$308.1M -28.7%
  • APPLE INC-$278.1M -22.8%
  • INTUIT-$196.2M -85.0%
  • AMAZON COM INC-$185.3M -28.1%
  • DONALDSON INC-$134.0M -97.7%
Show all 141 →

New Positions

  • GE AEROSPACE$295.5M
  • CROWDSTRIKE HLDGS INC$214.8M
  • SEAGATE TECHNOLOGY HLDNGS PL$184.2M
  • CANADIAN NAT RES LTD MED TER$143.7M
  • FORGENT POWER SOLUTIONS INC$140.6M
Show all 47 →

Exited Positions

  • COHERENT CORP$159.2M
  • VEEVA SYS INC$113.0M
  • DOXIMITY INC$112.6M
  • PLANET FITNESS MASTER ISSUER$108.0M
  • POOL CORP$91.5M
Show all 57 →
All Holdings

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 $2.36B 7.09% 4,936,408 SH
2 NVIDIA CORPORATION NVDA 67066G104 $1.72B 5.17% 8,599,021 SH
3 ALPHABET INC GOOGL 02079K305 $1.14B 3.43% 3,191,012 SH
4 APPLE INC AAPL 037833100 $943.3M 2.84% 3,259,914 SH
5 BROADCOM INC AVGO 11135F101 $776.7M 2.34% 2,056,135 SH
6 MICROSOFT CORP MSFT 594918104 $764.2M 2.30% 2,048,642 SH
7 META PLATFORMS INC META 30303M102 $535.2M 1.61% 950,115 SH
8 AMAZON COM INC AMZN 023135106 $473.6M 1.42% 1,987,085 SH
9 MASTERCARD INCORPORATED MA 57636Q104 $471.5M 1.42% 918,005 SH
10 ADVANCED MICRO DEVICES INC AMD 007903107 $443.5M 1.33% 763,517 SH
11 APPLIED MATLS INC AMAT 038222105 $360.0M 1.08% 497,946 SH
12 GE AEROSPACE GE 369604301 $295.5M 0.89% 790,801 SH
13 ASTRAZENECA PLC AZN G0593M107 $283.2M 0.85% 1,514,795 SH
14 PRIMO BRANDS CORPORATION PRMB 741623102 $279.3M 0.84% 11,426,823 SH
15 EVERPURE INC P 74624M102 $272.2M 0.82% 3,455,381 SH
16 AMPHENOL CORP APH 032095101 $270.7M 0.81% 1,535,059 SH
17 LINDE PLC LIN G54950103 $262.0M 0.79% 504,953 SH
18 ONTO INNOVATION INC ONTO 683344105 $251.8M 0.76% 665,377 SH
19 BORGWARNER INC BWA 099724106 $251.3M 0.76% 3,784,707 SH
20 CARLYLE GROUP INC CG 14316J108 $249.1M 0.75% 5,914,905 SH
21 ARGENX SE ARGX 04016X101 $245.5M 0.74% 264,617 SH
22 MUELLER INDS INC MLI 624756102 $244.2M 0.73% 1,986,139 SH
23 MONSTER BEVERAGE CORP NEW MNST 61174X109 $244.0M 0.73% 2,538,136 SH
24 F5 INC FFIV 315616102 $243.9M 0.73% 586,271 SH
25 CREDICORP LTD BAP G2519Y108 $243.5M 0.73% 625,144 SH
26 CURTISS WRIGHT CORP CW 231561101 $240.4M 0.72% 317,306 SH
27 ITAU UNIBANCO HLDG S A ITUB 465562106 $231.1M 0.69% 28,283,482 SH
28 SNOWFLAKE INC SNOW 833445109 $229.3M 0.69% 901,087 SH
29 TWIST BIOSCIENCE CORP TWST 90184D100 $223.7M 0.67% 2,174,594 SH
30 TEVA PHARMACEUTICAL INDS LTD TEVA 881624209 $223.4M 0.67% 6,593,221 SH
31 UNITEDHEALTH GROUP INC UNH 91324P102 $217.5M 0.65% 523,387 SH
32 CROWDSTRIKE HLDGS INC CRWD 22788C105 $214.8M 0.65% 281,409 SH
33 REGAL REXNORD CORPORATION RRX 758750103 $212.3M 0.64% 891,139 SH
34 KRYSTAL BIOTECH INC KRYS 501147102 $211.9M 0.64% 570,153 SH
35 CARPENTER TECHNOLOGY CORP CRS 144285103 $205.2M 0.62% 332,607 SH
36 POWER INTEGRATIONS INC POWI 739276103 $199.5M 0.60% 2,382,007 SH
37 NVENT ELEC PLC NVT G6700G107 $198.1M 0.60% 1,167,763 SH
38 GUARDANT HEALTH INC GH 40131M109 $196.7M 0.59% 1,311,320 SH
39 HALOZYME THERAPEUTICS INC HALO 40637H109 $196.5M 0.59% 2,511,050 SH
40 TALEN ENERGY CORP TLN 87422Q109 $191.2M 0.58% 497,660 SH
41 TRANSUNION TRU 89400J107 $191.1M 0.57% 2,648,744 SH
42 CAMECO CORP CCJ 13321L108 $189.3M 0.57% 1,858,735 SH
43 STERLING INFRASTRUCTURE INC STRL 859241101 $187.8M 0.56% 223,697 SH
44 COSTCO WHOLESALE CORPORATION COST 22160K105 $186.5M 0.56% 199,355 SH
45 ALIGNMENT HEALTHCARE INC ALHC 01625V104 $184.8M 0.56% 7,761,403 SH
46 C H ROBINSON WORLDWIDE IN CHRW 12541W209 $184.3M 0.55% 978,297 SH
47 SEAGATE TECHNOLOGY HLDNGS PL STX G7997R103 $184.2M 0.55% 190,847 SH
48 DIODES INC DIOD 254543101 $184.2M 0.55% 1,682,686 SH
49 BWX TECHNOLOGIES INC BWXT 05605H100 $183.2M 0.55% 941,233 SH
50 AKAMAI TECHNOLOGIES INC AKAM 00971T101 $181.5M 0.55% 1,535,467 SH
Filing History
Period Filed AUM Holdings Accession
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