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WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC

Institutional InvestorSimilar funds →SEC EDGAR: CIK 1644956
Institutional-grade research for retail investors

Sector Allocation

  • Technology42.5%$14.1B
  • Healthcare13.9%$4.6B
  • Industrials12.7%$4.2B
  • Financials10.4%$3.5B
  • Consumer Discretionary6.2%$2.0B
  • Materials4.7%$1.6B
  • Consumer Staples3.0%$1.0B
  • Energy2.7%$891.5M
  • Utilities1.2%$400.1M
  • Communication Services1.0%$340.8M

AUM History

13fpro.ai/research/fund/william-blair-investment-management-llc-1644956

Conviction and streaks

Diversifying · top 10 = 28.9%

From the fund's last 12 quarters of 13F filings: positions held longest at size, and names it added to or trimmed several quarters running.

TSM$TSMConviction hold7.1% weight · held 10 quartersNVDA$NVDAConviction hold5.2% weight · held 10 quartersGOOG$GOOGConviction hold3.4% weight · held 10 quartersAAPL$AAPLConviction hold2.8% weight · held 9 quartersAVGO$AVGOConviction hold2.3% weight · held 9 quartersDFIN$DFINAccumulating+98% shares · 8 quarters runningSTEP$STEPAccumulating+358% shares · 7 quarters runningPWP$PWPAccumulating+264% shares · 7 quarters runningPRCT$PRCTAccumulating+234% shares · 7 quarters runningBKV$BKVAccumulating+41% shares · 5 quarters runningTSM$TSMTrimming-48% shares · 9 quarters runningBDC$BDCTrimming-58% shares · 9 quarters runningMSFT$MSFTTrimming-55% shares · 7 quarters runningAMZN$AMZNTrimming-71% shares · 7 quarters runningASR$ASRTrimming-33% shares · 7 quarters running

Largest positions — Q2 2026

Top 20 stock positions. Options are left out: 13F reports them at the underlying's value.

13fpro.ai/research/fund/william-blair-investment-management-llc-1644956

WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC 13F holdings — Q2 2026

$33.3B portfolio (+9.9% QoQ) · 403 holdings · Q2 2026 13F · top 10 are 29% of the stock portfolio

All holdings — WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC (Q2 2026)

403 disclosed positions from the Form 13F-HR on SEC EDGAR, with quarter-over-quarter share changes. Largest by value first; the ten above are not repeated.

Company
AMAT$AMATAPPLIED MATERIALS INC /DE$360.0M+1325%
GE$GEGENERAL ELECTRIC CO$295.5MNew
AZN$AZNASTRAZENECA PLC$283.2M-22%
PRMB$PRMBPrimo Brands Corp$279.3M-12%
— EVERPURE INC - CL A$272.2M+20%
APH$APHAMPHENOL CORP /DE/$270.7M+42%
LIN$LINLINDE PLC$262.0M-21%
ONTO$ONTOONTO INNOVATION INC.$251.8M-31%
BWA$BWABORGWARNER INC$251.3M+31%
CG$CGCarlyle Group Inc.$249.1M-6%
ARGX$ARGXARGENX SEadr$245.5M-0.5%
MLI$MLIMUELLER INDUSTRIES INC$244.2M-6%
MNST$MNSTMonster Beverage Corp$244.0M-14%
FFIV$FFIVF5, INC.$243.9M-10%
BAP$BAPCREDICORP LTD$243.5M+0.4%

What changed in Q2 2026

Against the previous quarter's 13F: 46 new, 119 added to, 231 trimmed, 56 sold out. Share-count changes; largest moves by dollar size first.

New positions (46)

  • GE$GEGENERAL ELECTRIC CO$295.5M

    first bought this quarter

  • CRWD$CRWDCrowdStrike Holdings, Inc.$214.8M

    first bought this quarter

  • STX$STXSeagate Technology Holdings plc$184.2M

    first bought this quarter

  • CNQ$CNQCANADIAN NATURAL RESOURCES Ltd$143.7M

    first bought this quarter

  • FPS$FPSForgent Power Solutions, Inc.$140.6M

    first bought this quarter

  • PTCT$PTCTPTC THERAPEUTICS, INC.$140.5M

    first bought this quarter

+40 more in the Excel export

Added to (119)

  • AMAT$AMATAPPLIED MATERIALS INC /DE+1325%

    now $360.0M · held 6+ qtrs

  • GOOGL$GOOGLAlphabet Inc.+27%

    now $1.1B · held 6+ qtrs

  • TEVA$TEVATEVA PHARMACEUTICAL INDUSTRIES LTD+362%

    now $223.4M · held 2 qtrs, 2 adds in a row

  • DIOD$DIODDIODES INC /DEL/+281%

    now $184.2M · held 6+ qtrs

  • WST$WSTWEST PHARMACEUTICAL SERVICES INC+950%

    now $149.8M · held 6+ qtrs

  • MIRM$MIRMMirum Pharmaceuticals, Inc.+318%

    now $164.5M · held 4 qtrs

+113 more in the Excel export

Trimmed (231)

  • AAPL$AAPLApple Inc.-32%

    now $943.3M · held 6+ qtrs, 3 trims in a row

  • TWST$TWSTTwist Bioscience Corp-59%

    now $223.7M · held 6+ qtrs, 2 trims in a row

  • MSFT$MSFTMICROSOFT CORP-29%

    now $764.2M · held 6+ qtrs, 5 trims in a row

  • AMZN$AMZNAMAZON COM INC-37%

    now $473.6M · held 6+ qtrs, 2 trims in a row

  • TSM$TSMTAIWAN SEMICONDUCTOR MANUFACTURING CO LTD-11%

    now $2.4B · held 6+ qtrs, 5 trims in a row

  • TECH$TECHBIO-TECHNE Corp-100%

    now $287K

+225 more in the Excel export

Sold out (56)

  • COHR$COHRCOHERENT CORP.was $159.2M

    held 4 qtrs

  • VEEV$VEEVVEEVA SYSTEMS INCwas $113.0M

    held 9+ qtrs

  • DOCS$DOCSDoximity, Inc.was $112.6M

    held 9+ qtrs

  • PLNT$PLNTPlanet Fitness, Inc.was $108.0M

    held 8+ qtrs

  • POOL$POOLPOOL CORPwas $91.5M

    held 9+ qtrs

  • WMS$WMSADVANCED DRAINAGE SYSTEMS, INC.was $89.9M

+50 more in the Excel export

Firm AUM (Form ADV): $65.6B as of 2025-12-31 · SEC IAPD

Share

Holdings by quarter

Every 13F WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC has filed, 40 earlier quarters. Pick one to see what it held then.

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Is it too late to follow WILLIAM BLAIR INVESTMENT MANAGEMENT?

Q2 2026 13F filed with the SEC on Aug 12, 2026. Prices are closing prices as of Oct 26, 2026.

Average quality of WILLIAM BLAIR INVESTMENT MANAGEMENT's top 20 holdings: 77/100 (our AI quality score, weighted by position size; 16 of the 20 are scored)

Top 10 since filing

-0.5%

Value-weighted move of the 10 largest stock positions

Turnover

17%

Last quarter; 49% over the last 4

Top 10 weight

29%

Share of the stock portfolio in its 10 largest positions

Held 4+ quarters

77%

Share of portfolio value in positions held a year or more

Highest-quality names it owns(among its 100 largest positions)

The 8 highest-scoring companies in this portfolio are a Pro feature.

How these are measured
  • Moves since the quarter-end and since the filing date use our own daily closing prices, from the close on (or just before) each date to the latest close.
  • Turnover is the lesser of shares bought or sold in a quarter, valued at the quarter-end prices in the 13F, divided by the average of the two quarters' stock portfolio values.
  • Quarters held and add/trim streaks count back only through quarters whose filed holdings add up to the filing's own cover-page total (back to Q1 2025 for this fund). A change counts as an add or a trim when the split-adjusted share count moves by more than 1%.
  • Estimate, not the fund's reported cost. For each quarter in the current holding period in which the fund's share count rose (split-adjusted), we take that quarter's average daily close and weight it by the shares added; sales do not change an average cost. Quarters where the stock's price history and the 13F's own implied price disagree by more than 2x are left out.
  • Put and call option rows report the value of the underlying shares, not a position the fund paid for, so they are left out of all of the above.

Portfolio Overview

WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC disclosed 403 positions worth $33.3B in its Form 13F-HR for Q2 2026, led by $TSM (TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD) at 7.1% of the equity portfolio, followed by $NVDA and $GOOGL. During the quarter the fund opened 46 new positions and exited 56 — including a new stake in $GE and a full exit from $COHR. The portfolio is most concentrated in Technology (42.5% of disclosed assets). All figures are sourced directly from WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC’s Form 13F-HR filing with the SEC under CIK 1644956.

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AI-Powered Hedge Fund Analysis: WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC

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Every holding in WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC's portfolio is scored on an AI quality ranking built from its SEC filings (ROIC, FCF margin, revenue growth, institutional flow, earnings quality, shareholder dilution, and more). Track accumulation and distribution quarter over quarter, identify conviction positions, and see AI stock analysis for each position — alongside 8,700+ other institutional filers and 2,800+ AI-ranked companies.