William Blair Investment Management, LLC
In its 13F for Q1 2026 (holdings as of March 31, 2026, filed May 8, 2026), William Blair Investment Management, LLC reported 413 stock positions worth $30.3 billion. Its top holding was Taiwan Semiconductor-SP ADR (TSM) at 6.2% of the portfolio, followed by Nvidia (NVDA, 5.2%) and Apple (AAPL, 4.0%). Compared with Q4 2025, it opened 46 new positions, sold out of 46, added to 157 and reduced 205. The biggest buy was Astrazeneca (AZN, shares +8154%) and the biggest sale Microsoft (MSFT, shares −17%).
- Most Recent 13F
- Q2 2026
- Location
- CHICAGO, IL
- CIK
- 0001644956
- Portfolio Value
- $30.3B (Q1 2026)
- SEC Filing
- 0001644956-26-000021 ↗ filed May 8, 2026
Holdings Value
Holdings 413 stocks · $30.3B
| TSM Taiwan Semiconductor-SP ADR | 6.16% | 5,518,260 | $1.9B | Reduce -7.8% |
| NVDA Nvidia Corp. | 5.15% | 8,941,756 | $1.6B | Reduce -15.9% |
| AAPL Apple Inc. | 4.04% | 4,812,433 | $1.2B | Reduce -11.6% |
| MSFT Microsoft Corp. | 3.54% | 2,896,782 | $1.1B | Reduce -17.0% |
| GOOGL Alphabet Inc. Class A | 2.38% | 2,504,605 | $720.2M | Reduce -20.6% |
| AVGO Broadcom Inc. | 2.25% | 2,201,558 | $681.4M | Reduce -13.2% |
| AMZN Amazon.com Inc. | 2.18% | 3,163,629 | $658.9M | Reduce -27.9% |
| META Meta Platforms Inc. Class A | 1.92% | 1,013,122 | $579.6M | Reduce -14.6% |
| MA Mastercard Inc. Class A | 1.75% | 1,060,651 | $530.0M | Reduce -2.2% |
| AZN Astrazeneca PLC | 1.25% | 1,942,155 | $377.3M | Add +8154.1% |
| LIN Linde PLC | 1.04% | 636,338 | $315.5M | Reduce -1.1% |
| CG The Carlyle Group Inc. | 1.01% | 6,301,109 | $304.9M | Reduce -11.7% |
| COST Costco Wholesale Corp. | 1.00% | 302,468 | $301.4M | Reduce -7.9% |
| ITUB Itau Unibanco H-Spon PRF ADR | 0.88% | 31,684,708 | $265.6M | Reduce -13.3% |
| TWST Twist Bioscience Corp. | 0.83% | 5,269,718 | $250.4M | Reduce -11.5% |
| NOW ServiceNow Inc. | 0.82% | 2,371,614 | $248.0M | Add +10.4% |
| PRMB Primo Brands Corp. | 0.81% | 13,056,192 | $245.8M | Add +3.4% |
| MLI Mueller Industries Inc. | 0.77% | 2,109,729 | $233.8M | Add +18.5% |
| INTU Intuit Inc. | 0.76% | 533,736 | $230.8M | Add +20.6% |
| MNST Monster Beverage Corp. | 0.70% | 2,935,247 | $212.7M | Reduce -22.0% |
| AMD Advanced Micro Devices | 0.70% | 1,042,594 | $212.1M | Reduce -22.2% |
| BAP Credicorp Ltd. | 0.70% | 622,690 | $211.2M | Reduce -18.9% |
| A Agilent Technologies Inc. | 0.68% | 1,795,764 | $204.7M | Reduce -12.9% |
| ORLY O'reilly Automotive Inc. | 0.67% | 2,210,034 | $204.0M | Reduce -25.9% |
| BWXT BWX Technologies Inc. | 0.66% | 981,782 | $200.8M | Reduce -11.4% |
| TRU Transunion | 0.66% | 2,891,187 | $200.0M | Reduce -27.1% |
| ONTO Onto Innovation Inc. | 0.65% | 964,213 | $197.7M | Reduce -44.1% |
| IDXX Idexx Laboratories Inc. | 0.65% | 351,621 | $197.6M | Reduce -20.3% |
| NXT Nextpower Inc. | 0.65% | 1,622,489 | $195.6M | Add +19.1% |
| ARGX Argenx SE - ADR | 0.64% | 266,067 | $194.4M | Add +19.0% |
| CAVA Cava Group Inc. | 0.64% | 2,393,971 | $193.7M | Reduce -1.0% |
| LSCC Lattice Semiconductor Corp. | 0.63% | 2,043,720 | $189.6M | Reduce -3.8% |
| FFIV F5 Inc. | 0.62% | 649,948 | $188.0M | Add +18.1% |
| AKAM Akamai Technologies Inc. | 0.61% | 1,619,060 | $185.9M | New |
| CCJ Cameco Corp. | 0.60% | 1,682,303 | $182.7M | Reduce -15.1% |
| UNH Unitedhealth Group Inc. | 0.60% | 673,263 | $182.2M | Reduce -11.7% |
| MDGL Madrigal Pharmaceuticals Inc. | 0.59% | 340,519 | $178.3M | Reduce -3.9% |
| NU Nu Holdings Ltd./Cayman Isl-A filed as NU HLDGS LTD | 0.58% | 12,267,600 | $176.3M | Reduce -34.4% |
| GMED Globus Medical Inc. Class A | 0.57% | 2,009,763 | $173.2M | Reduce -20.2% |
| CHRW C.H. Robinson Worldwide Inc. | 0.57% | 1,041,658 | $173.0M | Add +138.1% |
| P Everpure Inc. Class A | 0.56% | 2,881,481 | $170.1M | Reduce -23.0% |
| SNOW Snowflake Inc. | 0.56% | 1,127,525 | $170.1M | Reduce -16.3% |
| TLN Talen Energy Corp. | 0.55% | 525,214 | $167.7M | Reduce -7.8% |
| LOPE Grand Canyon Education Inc. | 0.55% | 979,734 | $166.6M | Add +116.2% |
| EG Everest Group Ltd. | 0.55% | 506,166 | $165.4M | Reduce -13.4% |
| HALO Halozyme Therapeutics Inc. | 0.54% | 2,525,975 | $163.3M | Add +37.1% |
| MLM Martin Marietta Materials | 0.53% | 272,392 | $160.4M | Add +0.8% |
| COHR Coherent Corp. | 0.53% | 668,137 | $159.2M | Reduce -23.5% |
| CW Curtiss-Wright Corp. | 0.52% | 232,069 | $158.1M | Reduce -16.5% |
| RRX Regal Rexnord Corp. | 0.52% | 837,493 | $156.8M | Add +10.3% |
| BWA Borgwarner Inc. | 0.52% | 2,884,062 | $156.5M | New |
| CIEN Ciena Corp. | 0.51% | 398,579 | $154.7M | Reduce -63.7% |
| BWIN Baldwin Insurance Group Inc./ filed as THE BALDWIN INSURANCE GRP IN | 0.49% | 6,794,492 | $149.1M | Reduce -9.9% |
| INSM Insmed Inc. | 0.49% | 902,666 | $147.6M | Reduce -26.1% |
| NVT Nvent Electric PLC | 0.48% | 1,233,874 | $145.9M | Reduce -10.3% |
| CPRT Copart Inc. | 0.48% | 4,394,187 | $145.9M | Reduce -4.2% |
| HQY Healthequity Inc. | 0.46% | 1,659,616 | $138.7M | Reduce -10.5% |
| CRS Carpenter Technology | 0.46% | 350,896 | $138.3M | Reduce -16.0% |
| DCI Donaldson Co. Inc. | 0.45% | 1,615,349 | $137.1M | Reduce -5.4% |
| APH Amphenol Corp. Class A | 0.45% | 1,077,434 | $136.1M | New |
| LECO Lincoln Electric Holdings | 0.44% | 534,851 | $133.2M | Reduce -12.3% |
| STRL Sterling Infrastructure Inc. | 0.44% | 323,421 | $131.7M | Add +684.0% |
| MELI MercadoLibre Inc. | 0.43% | 74,849 | $129.4M | Reduce -54.8% |
| TECH Bio-Techne Corp. | 0.43% | 2,462,487 | $128.7M | Add +2.7% |
| CLH Clean Harbors Inc. | 0.42% | 443,098 | $127.0M | Add +30.6% |
| CMG Chipotle Mexican Grill Inc. | 0.41% | 3,910,673 | $125.2M | Add +18.0% |
| RS Reliance Inc. | 0.41% | 403,487 | $122.6M | Add +43.9% |
| POWI Power Integrations Inc. | 0.40% | 2,380,677 | $121.9M | New |
| EXP Eagle Materials Inc. | 0.39% | 630,392 | $119.4M | Add +12.8% |
| DT Dynatrace Inc. | 0.39% | 3,229,051 | $119.4M | Add +0.4% |
| BSY Bentley Systems Inc. Class B | 0.39% | 3,322,723 | $116.7M | Add +27.1% |
| GKOS Glaukos Corp. | 0.38% | 1,073,819 | $115.6M | Reduce -3.0% |
| FHN First Horizon Corp. | 0.38% | 5,058,092 | $115.1M | Reduce -5.2% |
| SN Sharkninja Inc. | 0.38% | 1,073,384 | $113.7M | Reduce -13.2% |
| VEEV Veeva Systems Inc. Class A | 0.37% | 643,325 | $113.0M | Reduce -27.0% |
| DOCS Doximity Inc. Class A | 0.37% | 4,834,220 | $112.6M | Reduce -11.4% |
| SYNA Synaptics Inc. | 0.37% | 1,586,244 | $111.1M | New |
| EYE National Vision Holdings Inc. | 0.36% | 4,225,766 | $109.4M | Reduce -6.3% |
| PLNT Planet Fitness Inc. Class A | 0.36% | 1,452,642 | $108.0M | Reduce -0.5% |
| DBD Diebold Nixdorf Inc. | 0.36% | 1,426,464 | $107.6M | Reduce -20.9% |
| FRPT Freshpet Inc. | 0.35% | 1,813,185 | $106.9M | Reduce -7.2% |
| TIGO Millicom Intl Cellular S.A. | 0.35% | 1,405,608 | $105.3M | Add +1022.9% |
| KRYS Krystal Biotech Inc. | 0.35% | 407,178 | $105.2M | Add +8.2% |
| GTX Garrett Motion Inc. | 0.35% | 5,762,697 | $104.7M | Reduce -4.9% |
| VRSK Verisk Analytics Inc. | 0.34% | 547,504 | $103.9M | Add +37.0% |
| LFUS Littelfuse Inc. | 0.34% | 304,575 | $103.4M | New |
| APPF Appfolio Inc. Class A | 0.34% | 643,231 | $101.5M | Add +0.8% |
| CWST Casella Waste Systems Inc. Class A | 0.33% | 1,257,092 | $99.7M | Reduce -14.4% |
| CHDN Churchill Downs Inc. | 0.32% | 1,093,389 | $98.2M | Reduce -4.5% |
| NBHC National Bank Hold Class A | 0.32% | 2,474,861 | $96.9M | New |
| NOVT Novanta Inc. | 0.31% | 783,084 | $92.5M | Reduce -13.8% |
| BIRK Birkenstock Holding PLC | 0.30% | 2,575,402 | $92.3M | New |
| ALHC Alignment Healthcare Inc. | 0.30% | 5,214,614 | $91.9M | Add +126.2% |
| POOL Pool Corp. | 0.30% | 452,273 | $91.5M | Reduce -13.0% |
| STEP Stepstone Group Inc. Class A | 0.30% | 1,914,477 | $91.4M | Add +185.7% |
| WMS Advanced Drainage Systems Inc. | 0.30% | 655,684 | $89.9M | Reduce -4.7% |
| KMT Kennametal Inc. | 0.30% | 2,482,535 | $89.7M | New |
| GH Guardant Health Inc. | 0.29% | 951,114 | $87.9M | New |
| ONB Old National Bancorp | 0.28% | 3,894,798 | $86.1M | Reduce -34.6% |
| FN Fabrinet | 0.28% | 164,830 | $86.0M | Reduce -17.7% |
Portfolio Sells Q4 2025 → Q1 2026
| MSFT Microsoft Corp. | Reduce -17.0% | 3.54% | −1.16 |
| SE Sea Ltd.-ADR | Sold out | 0.00% | −0.84 |
| ORCL Oracle Corp. | Reduce -95.6% | 0.03% | −0.66 |
| AMZN Amazon.com Inc. | Reduce -27.9% | 2.18% | −0.65 |
| MELI MercadoLibre Inc. | Reduce -54.8% | 0.43% | −0.50 |
| QTWO Q2 Holdings Inc. | Reduce -88.8% | 0.05% | −0.50 |
| WAY Waystar Holding Corp. | Sold out | 0.00% | −0.48 |
| FOLD Amicus Therapeutics Inc. | Sold out | 0.00% | −0.42 |
| CHE Chemed Corp. | Reduce -99.8% | 0.00% | −0.41 |
| WAL Western Alliance Bancorp | Sold out | 0.00% | −0.40 |
| CWAN Clearwater Analytics HDS-A | Sold out | 0.00% | −0.40 |
| BCO The Brink's Co. | Reduce -78.4% | 0.11% | −0.39 |
| TYL Tyler Technologies Inc. | Reduce -56.4% | 0.24% | −0.38 |
| NVDA Nvidia Corp. | Reduce -15.9% | 5.15% | −0.38 |
| GOOGL Alphabet Inc. Class A | Reduce -20.6% | 2.38% | −0.37 |
| TER Teradyne Inc. | Sold out | 0.00% | −0.37 |
| OWL Blue Owl Capital Inc. | Sold out | 0.00% | −0.32 |
| EXLS Exlservice Holdings Inc. | Sold out | 0.00% | −0.31 |
| DOCS Doximity Inc. Class A | Reduce -11.4% | 0.37% | −0.30 |
| PEN Penumbra Inc. | Sold out | 0.00% | −0.30 |
| NU Nu Holdings Ltd./Cayman Isl-A | Reduce -34.4% | 0.58% | −0.29 |
| TRU Transunion | Reduce -27.1% | 0.66% | −0.29 |
| GRAB Grab Holdings Ltd. Class A | Reduce -83.7% | 0.04% | −0.27 |
| META Meta Platforms Inc. Class A | Reduce -14.6% | 1.92% | −0.27 |
| BAM Brookfield Asset Mgmt-A | Sold out | 0.00% | −0.27 |
| SNOW Snowflake Inc. | Reduce -16.3% | 0.56% | −0.26 |
| CADE Cadence Bank | Sold out | 0.00% | −0.26 |
| MZTI The Marzetti Company | Sold out | 0.00% | −0.25 |
| CIEN Ciena Corp. | Reduce -63.7% | 0.51% | −0.21 |
| AVGO Broadcom Inc. | Reduce -13.2% | 2.25% | −0.20 |
| VRRM Verra Mobility Corp. | Reduce -88.7% | 0.02% | −0.20 |
| SPOT Spotify Technology SA | Reduce -51.8% | 0.17% | −0.19 |
| IDXX Idexx Laboratories Inc. | Reduce -20.3% | 0.65% | −0.18 |
| TME Tencent Music Entertainm-ADR | Sold out | 0.00% | −0.18 |
| VEEV Veeva Systems Inc. Class A | Reduce -27.0% | 0.37% | −0.18 |
| CG The Carlyle Group Inc. | Reduce -11.7% | 1.01% | −0.17 |
| ACGL Arch Capital Group Ltd. | Reduce -98.8% | 0.00% | −0.16 |
| ACVA Acv Auctions Inc. Class A | Reduce -33.8% | 0.10% | −0.14 |
| P Everpure Inc. Class A | Reduce -23.0% | 0.56% | −0.14 |
| WGS Genedx Holdings Corp. | Reduce -4.2% | 0.16% | −0.13 |
| MRCY Mercury Systems Inc. | Reduce -66.8% | 0.08% | −0.12 |
| CECO Ceco Environmental Corp. | Sold out | 0.00% | −0.12 |
| CACI Caci International Inc. Class A | Reduce -99.0% | 0.00% | −0.11 |
| ONTO Onto Innovation Inc. | Reduce -44.1% | 0.65% | −0.11 |
| TPG TPG Inc. | Reduce -22.5% | 0.15% | −0.11 |
| A Agilent Technologies Inc. | Reduce -12.9% | 0.68% | −0.11 |
| INSM Insmed Inc. | Reduce -26.1% | 0.49% | −0.10 |
| INSP Inspire Medical Systems Inc. | Reduce -2.1% | 0.19% | −0.10 |
| MNST Monster Beverage Corp. | Reduce -22.0% | 0.70% | −0.10 |
| UNH Unitedhealth Group Inc. | Reduce -11.7% | 0.60% | −0.10 |
Portfolio Buys Q4 2025 → Q1 2026
| AZN Astrazeneca PLC | Add +8154.1% | 1.25% | +1.23 |
| AKAM Akamai Technologies Inc. | New | 0.61% | +0.61 |
| BWA Borgwarner Inc. | New | 0.52% | +0.52 |
| APH Amphenol Corp. Class A | New | 0.45% | +0.45 |
| POWI Power Integrations Inc. | New | 0.40% | +0.40 |
| STRL Sterling Infrastructure Inc. | Add +684.0% | 0.44% | +0.40 |
| CHRW C.H. Robinson Worldwide Inc. | Add +138.1% | 0.57% | +0.38 |
| SYNA Synaptics Inc. | New | 0.37% | +0.37 |
| LFUS Littelfuse Inc. | New | 0.34% | +0.34 |
| LOPE Grand Canyon Education Inc. | Add +116.2% | 0.55% | +0.34 |
| TIGO Millicom Intl Cellular S.A. | Add +1022.9% | 0.35% | +0.33 |
| NBHC National Bank Hold Class A | New | 0.32% | +0.32 |
| NXT Nextpower Inc. | Add +19.1% | 0.65% | +0.32 |
| BIRK Birkenstock Holding PLC | New | 0.30% | +0.30 |
| KMT Kennametal Inc. | New | 0.30% | +0.30 |
| GH Guardant Health Inc. | New | 0.29% | +0.29 |
| CASY Casey's General Stores Inc. | New | 0.28% | +0.28 |
| CFR Cullen/Frost Bankers Inc. | New | 0.28% | +0.28 |
| TXN Texas Instruments Inc. | New | 0.27% | +0.27 |
| CYTK Cytokinetics Inc. | New | 0.24% | +0.24 |
| PRMB Primo Brands Corp. | Add +3.4% | 0.81% | +0.24 |
| TTE Totalenergies SE | Add +417.8% | 0.26% | +0.23 |
| APG Api Group Corp. | New | 0.23% | +0.23 |
| FFIV F5 Inc. | Add +18.1% | 0.62% | +0.23 |
| RRX Regal Rexnord Corp. | Add +10.3% | 0.52% | +0.22 |
| SCCO Southern Copper Corp. | New | 0.21% | +0.21 |
| MLI Mueller Industries Inc. | Add +18.5% | 0.77% | +0.20 |
| CLH Clean Harbors Inc. | Add +30.6% | 0.42% | +0.20 |
| SAIA Saia Inc. | New | 0.20% | +0.20 |
| HALO Halozyme Therapeutics Inc. | Add +37.1% | 0.54% | +0.19 |
| STEP Stepstone Group Inc. Class A | Add +185.7% | 0.30% | +0.18 |
| RS Reliance Inc. | Add +43.9% | 0.41% | +0.18 |
| ALHC Alignment Healthcare Inc. | Add +126.2% | 0.30% | +0.18 |
| TEX Terex Corp. | New | 0.17% | +0.17 |
| GFI Gold Fields Ltd.-Spons ADR | Add +3891.4% | 0.15% | +0.15 |
| TEVA Teva Pharmaceutical-SP ADR | New | 0.14% | +0.14 |
| VIST Vista Energy Sab DE CV | New | 0.14% | +0.14 |
| ARGX Argenx SE - ADR | Add +19.0% | 0.64% | +0.12 |
| HLIO Helios Technologies Inc. | Add +58.5% | 0.20% | +0.11 |
| LB Landbridge Co. LLC-A | Add +28.6% | 0.20% | +0.11 |
| BSY Bentley Systems Inc. Class B | Add +27.1% | 0.39% | +0.11 |
| KNX Knight-Swift Transportation | Add +73.3% | 0.18% | +0.10 |
| VRSK Verisk Analytics Inc. | Add +37.0% | 0.34% | +0.09 |
| MAR Marriott International Class A | New | 0.09% | +0.09 |
| KRYS Krystal Biotech Inc. | Add +8.2% | 0.35% | +0.09 |
| CATY Cathay General Bancorp | New | 0.09% | +0.09 |
| MTDR Matador Resources Co. | Add +49.6% | 0.13% | +0.08 |
| MDA Mda Space Ltd. | New | 0.08% | +0.08 |
| MGRC McGrath Rentcorp | New | 0.08% | +0.08 |
| TREX Trex Company Inc. | New | 0.08% | +0.08 |
All Filings
| Quarter | Positions | 13F Reported Value | Top Holdings |
|---|---|---|---|
| Q2 2026 | 403 | $33.3B | TSM, NVDA, GOOGL, AAPL, AVGO |
| Q1 2026 | 413 | $30.3B | TSM, NVDA, AAPL, MSFT, GOOGL |
| Q4 2025 | 413 | $35.9B | NVDA, TSM, MSFT, AAPL, AMZN |
| Q3 2025 | 414 | $38.7B | NVDA, MSFT, TSM, AAPL, AMZN |
| Q2 2025 | 417 | $37.7B | MSFT, NVDA, TSM, AMZN, AAPL |
| Q1 2025 | 423 | $35.6B | MSFT, NVDA, TSM, AMZN, AAPL |
| Q4 2024 | 433 | $40.9B | MSFT, NVDA, TSM, AMZN, AAPL |
| Q3 2024 | 412 | $40.5B | MSFT, NVDA, TSM, AAPL, AMZN |
| Q2 2024 | 411 | $38.1B | MSFT, NVDA, TSM, GOOGL, AMZN |
| Q1 2024 | 410 | $38.7B | MSFT, TSM, GOOGL, AMZN, NVDA |