WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC
Long book
$30.26B
Q1 2026
Positions
413
Top-10 weight
31%
concentration
Last quarter
+16.6%
SPY +14.8%
Turnover
20%
of book per quarter
Strategy in plain words
auto-generated from filingsWILLIAM BLAIR INVESTMENT MANAGEMENT, LLC is an institutional manager, running a $30.26B US long book across 413 positions.
The portfolio is moderately concentrated (top 10 ≈ 31% of the book). Turnover is modest: positions are typically held for years. Current anchor positions: TAIWAN SEMICONDUCTOR-SP ADR, NVIDIA CORP, APPLE INC, MICROSOFT CORP, ALPHABET INC-CL A.
Over the last 9 quarters its long book ran on average 1.3pp per quarter behind the S&P 500, beating the index in 2 of 9 quarters. Signal value of individual moves is limited — treat changes as weak evidence.
Implied long-book return vs S&P 500
methodology: positions priced quarterly, no shorts/options Fund long book S&P 500
Q1 2024
-0.8%
Q2 2024
+5.7%
Q3 2024
+1.0%
Q4 2024
-8.5%
Q1 2025
+12.8%
Q2 2025
+6.9%
Q3 2025
+0.0%
Q4 2025
-5.6%
Q1 2026
+16.6%
Sector allocation
Technology 36%
Industrials 12%
Financials 10%
Healthcare 10%
Services media 8%
Consumer discretionary 8%
Materials 4%
Other 4%
Long book by quarter
What does WILLIAM BLAIR own?
Q1 2026 13F| Company | Sector | Shares | Value | % of book | Change |
|---|---|---|---|---|---|
| NVDA NVIDIA CORP | Technology | 8.9M | $1.56B | 5.2% | -15.9% |
| AAPL APPLE INC | Technology | 4.8M | $1.22B | 4.0% | -11.6% |
| MSFT MICROSOFT CORP | Technology | 2.9M | $1.07B | 3.5% | -17.0% |
| GOOGL ALPHABET INC-CL A | Technology | 2.5M | $720.2M | 2.4% | -20.6% |
| AVGO BROADCOM INC | Technology | 2.2M | $681.4M | 2.3% | -13.2% |
| AMZN AMAZON.COM INC | Consumer discretionary | 3.2M | $658.9M | 2.2% | -27.9% |
| META META PLATFORMS INC-CLASS A | Technology | 1.0M | $579.6M | 1.9% | -14.6% |
| MA MASTERCARD INC - A | Services media | 1.1M | $530.0M | 1.8% | -2.2% |
| AZN ASTRAZENECA PLC | Healthcare | 1.9M | $377.3M | 1.2% | New |
| LIN LINDE PLC | Materials | 636.3K | $315.5M | 1.0% | -1.1% |
| CG CARLYLE GROUP INC/THE | Financials | 6.3M | $304.9M | 1.0% | -11.6% |
| COST COSTCO WHOLESALE CORP | Consumer discretionary | 302.5K | $301.4M | 1.0% | -7.9% |
| TWST TWIST BIOSCIENCE CORP | Healthcare | 5.3M | $250.4M | 0.8% | -11.5% |
| NOW SERVICENOW INC | Technology | 2.4M | $248.0M | 0.8% | +10.4% |
| PRMB PRIMO BRANDS CORP | Consumer staples | 13.1M | $245.8M | 0.8% | +3.4% |
| MLI MUELLER INDUSTRIES INC | Industrials | 2.1M | $233.8M | 0.8% | +18.5% |
| INTU INTUIT INC | Technology | 533.7K | $230.8M | 0.8% | +20.6% |
| MNST MONSTER BEVERAGE CORP | Consumer staples | 2.9M | $212.7M | 0.7% | -22.0% |
| AMD ADVANCED MICRO DEVICES | Technology | 1.0M | $212.1M | 0.7% | -22.2% |
| BAP CREDICORP LTD | Financials | 622.7K | $211.2M | 0.7% | -18.9% |
| A AGILENT TECHNOLOGIES INC | Healthcare | 1.8M | $204.7M | 0.7% | -13.0% |
| ORLY O'REILLY AUTOMOTIVE INC | Consumer discretionary | 2.2M | $204.0M | 0.7% | -25.9% |
| BWXT BWX TECHNOLOGIES INC | Industrials | 981.8K | $200.8M | 0.7% | -11.4% |
| TRU TRANSUNION | Services media | 2.9M | $200.0M | 0.7% | -27.1% |
| ONTO ONTO INNOVATION INC | Other | 964.2K | $197.7M | 0.7% | -44.2% |
| IDXX IDEXX LABORATORIES INC | Materials | 351.6K | $197.6M | 0.7% | -20.3% |
| NXT NEXTPOWER INC-CL A | Technology | 1.6M | $195.6M | 0.6% | +19.1% |
| CAVA CAVA GROUP INC | Consumer discretionary | 2.4M | $193.7M | 0.6% | -1.0% |
| LSCC LATTICE SEMICONDUCTOR CORP | Technology | 2.0M | $189.6M | 0.6% | -3.8% |
| FFIV F5 INC | Technology | 649.9K | $188.0M | 0.6% | +18.1% |
| AKAM AKAMAI TECHNOLOGIES INC | Services media | 1.6M | $185.9M | 0.6% | New |
| CCJ CAMECO CORP | Materials | 1.7M | $182.7M | 0.6% | -15.1% |
| UNH UNITEDHEALTH GROUP INC | Financials | 673.3K | $182.2M | 0.6% | -11.7% |
| MDGL MADRIGAL PHARMACEUTICALS INC | Healthcare | 340.5K | $178.3M | 0.6% | -3.9% |
| NU NU HOLDINGS LTD/CAYMAN ISL-A | Financials | 12.3M | $176.3M | 0.6% | -34.4% |
| GMED GLOBUS MEDICAL INC - A | Healthcare | 2.0M | $173.2M | 0.6% | -20.2% |
| CHRW C.H. ROBINSON WORLDWIDE INC | Industrials | 1.0M | $173.0M | 0.6% | +138.1% |
| P EVERPURE INC-A | Technology | 2.9M | $170.1M | 0.6% | -23.0% |
| SNOW SNOWFLAKE INC | Technology | 1.1M | $170.1M | 0.6% | -16.3% |
| TLN TALEN ENERGY CORP | Utilities | 525.2K | $167.7M | 0.6% | -7.8% |
| LOPE GRAND CANYON EDUCATION INC | Services media | 979.7K | $166.6M | 0.6% | +116.2% |
| EG EVEREST GROUP LTD | Financials | 506.2K | $165.4M | 0.5% | -13.4% |
| HALO HALOZYME THERAPEUTICS INC | Healthcare | 2.5M | $163.3M | 0.5% | +37.1% |
| MLM MARTIN MARIETTA MATERIALS | Materials | 272.4K | $160.4M | 0.5% | +0.8% |
| COHR COHERENT CORP | Other | 668.1K | $159.2M | 0.5% | -23.5% |
| CW CURTISS-WRIGHT CORP | Industrials | 232.1K | $158.1M | 0.5% | -16.5% |
| RRX REGAL REXNORD CORP | Industrials | 837.5K | $156.8M | 0.5% | +10.3% |
| BWA BORGWARNER INC | Industrials | 2.9M | $156.5M | 0.5% | New |
| CIEN CIENA CORP | Technology | 398.6K | $154.7M | 0.5% | -63.7% |
| BWIN BALDWIN INSURANCE GROUP INC/ | Financials | 6.8M | $149.1M | 0.5% | -9.9% |
13F filing history
| Period | Form | Filed | Entries | Reported value | Flags | Source |
|---|---|---|---|---|---|---|
| Q1 2026 | 13F-HR | May 8, 2026 | 413 | $30.26B | canonical | SEC ↗ |
| Q4 2025 | 13F-HR | Feb 9, 2026 | 413 | $35.85B | canonical | SEC ↗ |
| Q3 2025 | 13F-HR | Nov 12, 2025 | 414 | $38.67B | canonical | SEC ↗ |
| Q2 2025 | 13F-HR | Jul 29, 2025 | 417 | $37.68B | canonical | SEC ↗ |
| Q1 2025 | 13F-HR | May 9, 2025 | 423 | $35.62B | canonical | SEC ↗ |
| Q4 2024 | 13F-HR | Feb 10, 2025 | 433 | $40.94B | canonical | SEC ↗ |
| Q3 2024 | 13F-HR | Nov 8, 2024 | 412 | $40.53B | canonical | SEC ↗ |
| Q2 2024 | 13F-HR | Aug 8, 2024 | 411 | $38.12B | canonical | SEC ↗ |
| Q1 2024 | 13F-HR | May 8, 2024 | 410 | $38.69B | canonical | SEC ↗ |
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