Arkolith/Funds/William Blair Investment Management, LLC

William Blair Investment Management, LLC

CIK 1644956Asset manager
Holdings as of Jun 30, 2026·disclosed Aug 12, 2026·~43-day 13F lag·13F-HR
Active Filer

William Blair Investment Management, LLC holds a diversified book of 403 stocks worth $33.3B as of Q2 2026 (disclosed Aug 12, 2026, a ~43-day 13F lag). This quarter they opened General Electric and trimmed Taiwan Semiconductor-SP ADR. Their largest long position is Taiwan Semiconductor-SP ADR at 7% of the equity book.

Opened
89
bought for the first time
Added to
119
already held, bought more
Trimmed
230
sold some, still holds it
Sold out
57
exited the position entirely

Concentration

Top-heavy: diversified book

Top 5 holdings
21%
Top 10 holdings
29%
Top 20 holdings
37%

Share of the disclosed book in its largest positions. A higher top-5 share means a more concentrated, higher-conviction portfolio.

Direct sector allocation

100% mapped to company sectors

Information Technology
43%
Health Care
13%
Industrials
13%
Financials
10%
Consumer Discretionary
8%
Materials
5%
Consumer Staples
2%
Energy
2%

Direct operating-company sectors from our SIC-based security master. ETF/fund and unclassified holdings stay visible separately; this is not ETF look-through exposure.

Biggest moves: latest quarter

Estimated $ traded · quarter-end prices, no cost basis

Bought
Trimmed / exited

Funds with the most overlap

Other tracked managers holding the same core names as William Blair Investment Management, LLC

Manager / fundShared namesTheir $ in those
BlackRock, Inc.80 / 80$1.7T
FMR LLC80 / 80$695.1B
JPMORGAN CHASE & CO80 / 80$367.7B
MORGAN STANLEY80 / 80$353.9B
NORTHERN TRUST CORP80 / 80$219.8B
BANK OF AMERICA CORP /DE/80 / 80$205.1B
GOLDMAN SACHS GROUP INC80 / 80$176.5B
Bank of New York Mellon Corp80 / 80$151.9B

Ranked by how many of William Blair Investment Management, LLC's top 80 disclosed names each fund also holds: a cross-fund conviction signal from the latest 13F of every tracked manager.

Holdings: largest first

Bars show each stock's share of the portfolio. Click a row for its position history.

403 positions
#SecurityValueShares% PortLast moveHistory
1Taiwan Semiconductor Manufac
SPONSORED ADS
$2.4B4.94M
7.1%
−11%
Reduced · −582K sh
2Nvidia Corporation
COM
$1.7B8.60M
5.2%
−3.8%
Reduced · −343K sh
3Alphabet Inc
CAP STK CL A
$1.1B3.19M
3.4%
+27%
Added · +686K sh
4Apple Inc
COM
$943.3M3.26M
2.8%
−32%
Reduced · −1.6M sh
5Broadcom Inc
COM
$776.7M2.06M
2.3%
−6.6%
Reduced · −145K sh
6Microsoft Corp
COM
$764.2M2.05M
2.3%
−29%
Reduced · −848K sh
7Meta Platforms Inc
CL A
$535.2M950.1K
1.6%
−6.2%
Reduced · −63K sh
8Amazon Com Inc
COM
$473.6M1.99M
1.4%
−37%
Reduced · −1.2M sh
9Mastercard Incorporated
CL A
$471.5M918.0K
1.4%
−13%
Reduced · −143K sh
10Advanced Micro Devices Inc
COM
$443.5M763.5K
1.3%
−27%
Reduced · −279K sh
11Applied Matls Inc
COM
$360.0M497.9K
1.1%
14×
Added · +463K sh
12Ge Aerospace
COM NEW
$295.5M790.8K
0.9%
New
New position
13AstraZeneca PLC
ORD
$283.2M1.51M
0.9%
−22%
Reduced · −427K sh
14Primo Brands Corporation
CLASS A COM SHS
$279.3M11.43M
0.8%
−12%
Reduced · −1.6M sh
15Everpure Inc
CL A
$272.2M3.46M
0.8%
+20%
Added · +574K sh
16Amphenol Corp
CL A
$270.7M1.54M
0.8%
+42%
Added · +458K sh
17Linde PLC
SHS
$262.0M505.0K
0.8%
−21%
Reduced · −131K sh
18Onto Innovation Inc
COM
$251.8M665.4K
0.8%
−31%
Reduced · −299K sh
19Borgwarner Inc
COM
$251.3M3.78M
0.8%
+31%
Added · +901K sh
20Carlyle Group Inc
COM
$249.1M5.91M
0.7%
−6.1%
Reduced · −386K sh
21Argenx SE
SPONSORED ADR
$245.5M264.6K
0.7%
−0.5%
Reduced · −1K sh
22Mueller Inds Inc
COM
$244.2M1.99M
0.7%
−5.8%
Reduced · −124K sh
23Monster Beverage Corp New
COM
$244.0M2.54M
0.7%
−14%
Reduced · −397K sh
24F5 Inc
COM
$243.9M586.3K
0.7%
−9.8%
Reduced · −64K sh
25Credicorp Ltd
COM
$243.5M625.1K
0.7%
+0.4%
Added · +2K sh
26Curtiss Wright Corp
COM
$240.4M317.3K
0.7%
+37%
Added · +85K sh
27Itau Unibanco Hldg S A
SPON ADR REP PFD
$231.1M28.28M
0.7%
−11%
Reduced · −3.4M sh
28Snowflake Inc
COM SHS
$229.3M901.1K
0.7%
−20%
Reduced · −226K sh
29Twist Bioscience Corp
COM
$223.7M2.17M
0.7%
−59%
Reduced · −3.1M sh
30Teva Pharmaceutical Inds Ltd
SPONSORED ADS
$223.4M6.59M
0.7%
+362%
Added · +5.2M sh
31Unitedhealth Group Inc
COM
$217.5M523.4K
0.7%
−22%
Reduced · −150K sh
32Crowdstrike Hldgs Inc
CL A
$214.8M281.4K
0.6%
New
New position
33Regal Rexnord Corporation
COM
$212.3M891.1K
0.6%
+6.4%
Added · +54K sh
34Krystal Biotech Inc
COM
$211.9M570.2K
0.6%
+40%
Added · +163K sh
35Carpenter Technology Corp
COM
$205.2M332.6K
0.6%
−5.2%
Reduced · −18K sh
36Power Integrations Inc
COM
$199.5M2.38M
0.6%
+0.1%
Added · +1K sh
37Nvent Elec PLC
SHS
$198.1M1.17M
0.6%
−5.3%
Reduced · −66K sh
38Guardant Health Inc
COM
$196.7M1.31M
0.6%
+38%
Added · +360K sh
39Halozyme Therapeutics Inc
COM
$196.5M2.51M
0.6%
−0.6%
Reduced · −15K sh
40Talen Energy Corp
COM
$191.2M497.7K
0.6%
−5.2%
Reduced · −28K sh
41Transunion
COM
$191.1M2.65M
0.6%
−8.4%
Reduced · −242K sh
42Cameco Corp
COM
$189.3M1.86M
0.6%
+10%
Added · +176K sh
43Sterling Infrastructure Inc
COM
$187.8M223.7K
0.6%
−31%
Reduced · −100K sh
44Costco Wholesale Corporation
COM
$186.5M199.4K
0.6%
−34%
Reduced · −103K sh
45Alignment Healthcare Inc
COM
$184.8M7.76M
0.6%
+49%
Added · +2.5M sh
46C H Robinson Worldwide In
COM NEW
$184.3M978.3K
0.6%
−6.1%
Reduced · −63K sh
47Seagate Technology HLDNGS PL
ORD SHS
$184.2M190.8K
0.6%
New
New position
48Diodes Inc
COM
$184.2M1.68M
0.6%
+281%
Added · +1.2M sh
49BWX Technologies Inc
COM
$183.2M941.2K
0.6%
−4.1%
Reduced · −41K sh
50Akamai Technologies Inc
COM
$181.5M1.54M
0.5%
−5.2%
Reduced · −84K sh
Showing 50 of 403 positions
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Filing history

As-of date vs the date the SEC received each filing

QuarterAs ofFiledPositionsValueForm
Q2 2026Jun 30, 2026Aug 12, 2026403$33.3B13F-HR
Q1 2026Mar 31, 2026May 8, 2026413$30.3B13F-HR
Q4 2025Dec 31, 2025Feb 9, 2026413$35.9B13F-HR
Q3 2025Sep 30, 2025Nov 12, 2025414$38.7B13F-HR
Q2 2025Jun 30, 2025Jul 29, 2025417$37.7B13F-HR
Q1 2025Mar 31, 2025May 9, 2025423$35.6B13F-HR
Q4 2024Dec 31, 2024Feb 10, 2025433$40.9B13F-HR
Q3 2024Sep 30, 2024Nov 8, 2024412$40.5B13F-HR
Q2 2024Jun 30, 2024Aug 8, 2024411$38.1B13F-HR
Q1 2024Mar 31, 2024May 8, 2024410$38.7B13F-HR
Q4 2023Dec 31, 2023Feb 9, 2024406$34.4B13F-HR
Q3 2023Sep 30, 2023Nov 9, 2023398$30.1B13F-HR
Q2 2023Jun 30, 2023Aug 11, 2023395$31.2B13F-HR
Q1 2023Mar 31, 2023May 12, 2023393$28.7B13F-HR
Q4 2022Dec 31, 2022Feb 9, 2023401$26.1B13F-HR
Q3 2022Sep 30, 2022Nov 9, 2022387$25.3B13F-HR
Q2 2022Jun 30, 2022Aug 10, 2022403$27.0B13F-HR
Q1 2022Mar 31, 2022May 11, 2022441$33.5B13F-HR
Q4 2021Dec 31, 2021Feb 14, 2022427$37.0B13F-HR
Q3 2021Sep 30, 2021Nov 10, 2021431$35.5B13F-HR
Q2 2021Jun 30, 2021Aug 12, 2021465$31.9B13F-HR
Q1 2021Mar 31, 2021May 13, 2021367$30.9B13F-HR
Q4 2020Dec 31, 2020Feb 9, 2021356$30.0B13F-HR
Q3 2020Sep 30, 2020Nov 6, 2020343$25.7B13F-HR

Data source

Holdings from SEC EDGAR 13F-HR filings, updated quarterly, filed up to 45 days after quarter-end. Public domain. The book and weighting are long equity only; disclosed put/call options are listed separately and excluded from those totals. Price-derived performance is withheld until the price-source policy and freshness gate are green.