William Blair Investment Management, LLC holds a diversified book of 413 stocks worth $30.3B as of Q1 2026 (disclosed May 8, 2026, a ~45-day 13F lag). This quarter they opened AstraZeneca PLC and trimmed Taiwan Semiconductor-SP ADR. Their largest long position is Taiwan Semiconductor-SP ADR at 6% of the equity book.
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curl -H "Authorization: Bearer YOUR_API_KEY" \ "https://arkolith.com/api/v1/funds/1644956/holdings"
Use Arkolith to show WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC's latest holdings, largest changes, and filing provenance.
Top-heavy: diversified book
Share of the disclosed book in its largest positions. A higher top-5 share means a more concentrated, higher-conviction portfolio.
100% mapped to company sectors
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.
Estimated $ traded · quarter-end prices, no cost basis
Bars show each stock's share of the portfolio. Click a row for its position history.
| # | Security | Value | Shares | % Port | Last move | History |
|---|---|---|---|---|---|---|
| 1 | Taiwan Semiconductor Manufac SPONSORED ADS | $1.9B | 5.52M | 6.2% | ▼−7.8% Reduced · −467K sh | |
| 2 | Nvidia Corporation COM | $1.6B | 8.94M | 5.2% | ▼−16% Reduced · −1.7M sh | |
| 3 | Apple Inc COM | $1.2B | 4.81M | 4.0% | ▼−12% Reduced · −632K sh | |
| 4 | Microsoft Corp COM | $1.1B | 2.90M | 3.5% | ▼−17% Reduced · −594K sh | |
| 5 | Alphabet Inc CAP STK CL A | $720.2M | 2.50M | 2.4% | ▼−21% Reduced · −650K sh | |
| 6 | Broadcom Inc COM | $681.4M | 2.20M | 2.3% | ▼−13% Reduced · −335K sh | |
| 7 | Amazon Com Inc COM | $658.9M | 3.16M | 2.2% | ▼−28% Reduced · −1.2M sh | |
| 8 | Meta Platforms Inc CL A | $579.6M | 1.01M | 1.9% | ▼−15% Reduced · −174K sh | |
| 9 | Mastercard Incorporated CL A | $530.0M | 1.06M | 1.8% | ▼−2.2% Reduced · −24K sh | |
| 10 | AstraZeneca PLC ORD | $377.3M | 1.94M | 1.2% | ▲New New position | |
| 11 | Linde PLC SHS | $315.5M | 636.3K | 1.0% | ▼−1.1% Reduced · −7K sh | |
| 12 | Carlyle Group Inc COM | $304.9M | 6.30M | 1.0% | ▼−12% Reduced · −831K sh | |
| 13 | Costco Wholesale Corporation COM | $301.4M | 302.5K | 1.0% | ▼−7.9% Reduced · −26K sh | |
| 14 | Itau Unibanco Hldg S A SPON ADR REP PFD | $265.6M | 31.68M | 0.9% | ▼−13% Reduced · −4.9M sh | |
| 15 | Twist Bioscience Corp COM | $250.4M | 5.27M | 0.8% | ▼−11% Reduced · −685K sh | |
| 16 | Servicenow Inc COM | $248.0M | 2.37M | 0.8% | ▲+10% Added · +223K sh | |
| 17 | Primo Brands Corporation CLASS A COM SHS | $245.8M | 13.06M | 0.8% | ▲+3.4% Added · +429K sh | |
| 18 | Mueller Inds Inc COM | $233.8M | 2.11M | 0.8% | ▲+19% Added · +330K sh | |
| 19 | Intuit COM | $230.8M | 533.7K | 0.8% | ▲+21% Added · +91K sh | |
| 20 | Monster Beverage Corp New COM | $212.7M | 2.94M | 0.7% | ▼−22% Reduced · −826K sh | |
| 21 | Advanced Micro Devices Inc COM | $212.1M | 1.04M | 0.7% | ▼−22% Reduced · −297K sh | |
| 22 | Credicorp Ltd COM | $211.2M | 622.7K | 0.7% | ▼−19% Reduced · −145K sh | |
| 23 | Agilent Technologies Inc COM | $204.7M | 1.80M | 0.7% | ▼−13% Reduced · −267K sh | |
| 24 | Oreilly Automotive Inc COM | $204.0M | 2.21M | 0.7% | ▼−26% Reduced · −771K sh | |
| 25 | BWX Technologies Inc COM | $200.8M | 981.8K | 0.7% | ▼−11% Reduced · −126K sh | |
| 26 | Transunion COM | $200.0M | 2.89M | 0.7% | ▼−27% Reduced · −1.1M sh | |
| 27 | Onto Innovation Inc COM | $197.7M | 964.2K | 0.7% | ▼−44% Reduced · −762K sh | |
| 28 | Idexx Labs Inc COM | $197.6M | 351.6K | 0.7% | ▼−20% Reduced · −90K sh | |
| 29 | Nextpower Inc CLASS A COM | $195.6M | 1.62M | 0.6% | ▲+19% Added · +260K sh | |
| 30 | Argenx SE SPONSORED ADR | $194.4M | 266.1K | 0.6% | ▲+19% Added · +42K sh | |
| 31 | Cava Group Inc COM | $193.7M | 2.39M | 0.6% | ▼−1.0% Reduced · −25K sh | |
| 32 | Lattice Semiconductor Corp COM | $189.6M | 2.04M | 0.6% | ▼−3.8% Reduced · −82K sh | |
| 33 | F5 Inc COM | $188.0M | 649.9K | 0.6% | ▲+18% Added · +100K sh | |
| 34 | Akamai Technologies Inc COM | $185.9M | 1.62M | 0.6% | ▲New New position | |
| 35 | Cameco Corp COM | $182.7M | 1.68M | 0.6% | ▼−15% Reduced · −299K sh | |
| 36 | Unitedhealth Group Inc COM | $182.2M | 673.3K | 0.6% | ▼−12% Reduced · −89K sh | |
| 37 | Madrigal Pharmaceuticals Inc COM | $178.3M | 340.5K | 0.6% | ▼−3.9% Reduced · −14K sh | |
| 38 | Nu Hldgs Ltd ORD SHS CL A | $176.3M | 12.27M | 0.6% | ▼−34% Reduced · −6.4M sh | |
| 39 | Globus Med Inc CL A | $173.2M | 2.01M | 0.6% | ▼−20% Reduced · −510K sh | |
| 40 | C H Robinson Worldwide In COM NEW | $173.0M | 1.04M | 0.6% | ▲+138% Added · +604K sh | |
| 41 | Everpure Inc CL A | $170.1M | 2.88M | 0.6% | ▼−23% Reduced · −861K sh | |
| 42 | Snowflake Inc COM SHS | $170.1M | 1.13M | 0.6% | ▼−16% Reduced · −219K sh | |
| 43 | Talen Energy Corp COM | $167.7M | 525.2K | 0.6% | ▼−7.8% Reduced · −44K sh | |
| 44 | Grand Canyon Ed Inc COM | $166.6M | 979.7K | 0.6% | ▲+116% Added · +527K sh | |
| 45 | Everest Group Ltd COM | $165.4M | 506.2K | 0.5% | ▼−13% Reduced · −78K sh | |
| 46 | Halozyme Therapeutics Inc COM | $163.3M | 2.53M | 0.5% | ▲+37% Added · +683K sh | |
| 47 | Martin Marietta Matls Inc COM | $160.4M | 272.4K | 0.5% | ▲+0.8% Added · +2K sh | |
| 48 | Coherent Corp COM | $159.2M | 668.1K | 0.5% | ▼−23% Reduced · −205K sh | |
| 49 | Curtiss Wright Corp COM | $158.1M | 232.1K | 0.5% | ▼−16% Reduced · −46K sh | |
| 50 | Regal Rexnord Corporation COM | $156.8M | 837.5K | 0.5% | ▲+10% Added · +78K sh |
As-of date vs the date the SEC received each filing
| Quarter | As of | Filed | Positions | Value | Form |
|---|---|---|---|---|---|
| Q1 2026 | Mar 31, 2026 | May 8, 2026 | 413 | $30.3B | 13F-HR |
| Q4 2025 | Dec 31, 2025 | Feb 9, 2026 | 413 | $35.9B | 13F-HR |
| Q3 2025 | Sep 30, 2025 | Nov 12, 2025 | 414 | $38.7B | 13F-HR |
| Q2 2025 | Jun 30, 2025 | Jul 29, 2025 | 417 | $37.7B | 13F-HR |
| Q1 2025 | Mar 31, 2025 | May 9, 2025 | 423 | $35.6B | 13F-HR |
| Q4 2024 | Dec 31, 2024 | Feb 10, 2025 | 433 | $40.9B | 13F-HR |
| Q3 2024 | Sep 30, 2024 | Nov 8, 2024 | 412 | $40.5B | 13F-HR |
| Q2 2024 | Jun 30, 2024 | Aug 8, 2024 | 411 | $38.1B | 13F-HR |
| Q1 2024 | Mar 31, 2024 | May 8, 2024 | 410 | $38.7B | 13F-HR |
| Q4 2023 | Dec 31, 2023 | Feb 9, 2024 | 406 | $34.4B | 13F-HR |
| Q3 2023 | Sep 30, 2023 | Nov 9, 2023 | 398 | $30.1B | 13F-HR |
| Q2 2023 | Jun 30, 2023 | Aug 11, 2023 | 395 | $31.2B | 13F-HR |
| Q1 2023 | Mar 31, 2023 | May 12, 2023 | 393 | $28.7B | 13F-HR |
| Q4 2022 | Dec 31, 2022 | Feb 9, 2023 | 401 | $26.1B | 13F-HR |
| Q3 2022 | Sep 30, 2022 | Nov 9, 2022 | 387 | $25.3B | 13F-HR |
| Q2 2022 | Jun 30, 2022 | Aug 10, 2022 | 403 | $27.0B | 13F-HR |
| Q1 2022 | Mar 31, 2022 | May 11, 2022 | 441 | $33.5B | 13F-HR |
| Q4 2021 | Dec 31, 2021 | Feb 14, 2022 | 427 | $37.0B | 13F-HR |
| Q3 2021 | Sep 30, 2021 | Nov 10, 2021 | 431 | $35.5B | 13F-HR |
| Q2 2021 | Jun 30, 2021 | Aug 12, 2021 | 465 | $31.9B | 13F-HR |
| Q1 2021 | Mar 31, 2021 | May 13, 2021 | 367 | $30.9B | 13F-HR |
| Q4 2020 | Dec 31, 2020 | Feb 9, 2021 | 356 | $30.0B | 13F-HR |
| Q3 2020 | Sep 30, 2020 | Nov 6, 2020 | 343 | $25.7B | 13F-HR |
| Q2 2020 | Jun 30, 2020 | Aug 12, 2020 | 341 | $24.6B | 13F-HR |
Holdings from SEC EDGAR 13F-HR filings, updated quarterly ~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.