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13F holdings

BLAIR WILLIAM & CO/IL portfolio

Managed by . 1,922 reported positions worth $34.9B as of 2026-03-31, filed with the SEC on 2026-05-08. Parsed from the filing itself, not a reseller.

$34.9B
Book value
1,922
Positions
26%
Top 10 weight
+155
New this quarter
-100
Exited
134 days
Age today
How old this actually is

Every position on this page is a snapshot of 2026-03-31. It was already 38 days old on 2026-05-08, the day it first became public. Today it is 134 days old.

That lag is the law, not a service level — Rule 13f-1 gives managers 45 days after quarter end to file, and no product can shorten it. A fund can have sold every share below before you read this sentence. Treat it as a record of what happened, never as a position you can follow.

What changed

Positions opened and closed

Against its 2025-12-31 filing. This is the part worth reading — the holdings table below is mostly years old.

New positions (155)
TickerIssuerValueShares% of book
AZNASTRAZENECA PLC$19.8M100,6220.06%
SIMOSILICON MOTION TECHNOLOGY CO$11.6M103,1790.03%
GHGUARDANT HEALTH INC$9.6M103,6440.03%
SLDBSOLID BIOSCIENCES INC$4.7M651,2160.01%
RYNRAYONIER INC$2.7M130,9390.01%
EXPOEXPONENT INC$1.9M28,8060.01%
RLIRLI CORP$1.8M31,5730.01%
ICFIICF INTL INC$1.6M23,7840.00%
BLDRBUILDERS FIRSTSOURCE INC$1.1M13,4500.00%
SUNBSUNBELT RENTALS HOLDINGS INC$1.1M16,2000.00%
PINEALPINE INCOME PPTY TR INC$1.0M57,5150.00%
DFTXDEFINIUM THERAPEUTICS INC$1.0M53,6950.00%
AOMISHARES TR$993,87020,9810.00%
MANUMANCHESTER UTD PLC NEW$966,41057,4560.00%
DIODDIODES INC$955,98114,0050.00%
BATRAATLANTA BRAVES HLDGS INC$924,32919,6040.00%
MNRMACH NATURAL RESOURCES LP$874,00662,4290.00%
ARANTERO RESOURCES CORP$807,20219,0200.00%
NOGNORTHERN OIL & GAS INC$800,31727,3800.00%
CRLCHARLES RIV LABS INTL INC$789,1074,5750.00%
ALHCALIGNMENT HEALTHCARE INC$747,96942,4500.00%
TRPTC ENERGY CORP$675,76210,7950.00%
HALOHALOZYME THERAPEUTICS INC$659,42010,2030.00%
USOUNITED STS OIL FD LP$639,9405,0290.00%
MBWMMERCANTILE BK CORP$615,54512,1890.00%
Closed out (100)
TickerIssuerWas worthShares% of book
DVAXDYNAVAX TECHNOLOGIES CORP$27.4M1,781,4420.00%
AZNNASTRAZENECA PLC$19.4M211,1840.00%
CYBRCYBERARK SOFTWARE LTD$14.5M32,5920.00%
EXKEXACT SCIENCES CORP$13.1M128,5170.00%
QLYSQUALYS INC$6.4M47,9580.00%
GXOGXO LOGISTICS INCORPORATED$4.8M91,7910.00%
8QRCONFLUENT INC$4.8M159,2900.00%
DSGRDISTRIBUTION SOLUTIONS GRP I$3.1M112,8700.00%
8TGTHERMON GROUP HLDGS INC$2.3M61,0650.00%
BRSPBRIGHTSPIRE CAPITAL INC$2.1M370,5640.00%
MRCCMONROE CAP CORP$2.0M309,7500.00%
BROBROWN & BROWN INC$1.9M23,5450.00%
HO1HOLOGIC INC$1.5M20,0730.00%
BKVBKV CORP$1.1M42,3450.00%
CRKCOMSTOCK RES INC$940,45940,5720.00%
JAMFJAMF HLDG CORP$937,43672,0550.00%
CWENCLEARWAY ENERGY INC$792,24923,8200.00%
SDASEALED AIR CORP NEW$696,75916,8180.00%
FLYWFLYWIRE CORPORATION$580,85741,0210.00%
TWFGTWFG INC$572,40819,8960.00%
RVTYREVVITY INC$568,5035,8760.00%
SMWBSIMILARWEB LTD$532,12071,0440.00%
ACMAECOM$491,1975,1530.00%
PDDPDD HOLDINGS INC$462,5474,0790.00%
BCSBARCLAYS PLC$436,66917,1580.00%
Added to (657)
TickerIssuerValueShares% of bookShares Δ
GEVGE VERNOVA INC$580.1M664,6031.66%+2%
FASTFASTENAL CO$342.1M7,373,7070.98%+5%
RSPINVESCO EXCHANGE TRADED FD T$322.5M1,680,6040.92%+206%
VEUVANGUARD INTL EQUITY INDEX F$313.1M4,168,6250.90%+54%
AVGOBROADCOM INC$284.2M918,3280.81%+2%
VEAVANGUARD TAX-MANAGED FDS$247.5M3,862,0860.71%+23%
VOOVANGUARD INDEX FDS$237.5M397,3800.68%+6%
BRK/BBERKSHIRE HATHAWAY INC DEL$237.4M495,3220.68%+11%
VTVVANGUARD INDEX FDS$228.8M1,165,9120.66%+30%
PANWPALO ALTO NETWORKS INC$209.2M1,304,8580.60%+4%
BABOEING CO$183.5M922,1020.53%+36%
QQQINVESCO QQQ TR$179.5M311,0160.51%+11%
NFLXNETFLIX INC.$169.6M1,763,4510.49%+18%
GLDSPDR GOLD TR$166.4M386,7350.48%+52%
IWMISHARES TR$155.8M628,2280.45%+12%
Trimmed (647)
TickerIssuerValueShares% of bookShares Δ
MCHIISHARES TR$995180.00%-99%
STKLSUNOPTA INC$92,90414,3370.00%-99%
CWANCLEARWATER ANALYTICS HLDGS I$1.8M77,5820.01%-98%
VCLTVANGUARD SCOTTSDALE FDS$897120.00%-97%
TRUTRANSUNION$789,66511,4130.00%-96%
BILLBILL HOLDINGS INC$475,60812,4180.00%-95%
WINGWINGSTOP INC$1.0M6,7370.00%-93%
ONONON HLDG AG$776,84722,8350.00%-91%
ZNOVINNOVATOR ETFS TRUST$211,5507,9680.00%-90%
XTISHARES TR$70,8071,0390.00%-89%
IOTSAMSARA INC$4.7M149,7380.01%-89%
ITGARTNER INC$2.3M14,5060.01%-88%
IETCISHARES U S ETF TR$42,3344790.00%-88%
BLBLACKLINE INC$391,20110,5730.00%-88%
DSGXDESCARTES SYS GROUP INC$2.1M29,3600.01%-87%
The book

Largest 150 of 1,922 holdings

TickerIssuerValueShares% of bookShares Δ
AAPLAPPLE INC$1.5B5,930,9144.31%
MSFTMICROSOFT CORP$1.3B3,498,1103.71%
AMZNAMAZON COM INC$1.3B6,057,9383.62%
NVDANVIDIA CORPORATION$946.6M5,427,8752.71%
GOOGALPHABET INC$870.8M3,035,7652.50%
GOOGLALPHABET INC$700.5M2,436,1172.01%
JPMJPMORGAN CHASE & CO$678.7M2,307,2531.94%
GEVGE VERNOVA INC$580.1M664,6031.66%
VVISA INC$557.5M1,844,5831.60%
SPYSTATE STR SPDR S&P 500 ETF T$549.7M845,2941.58%
IDXXIDEXX LABS INC$531.7M946,3361.52%
COSTCOSTCO WHOLESALE CORPORATION$519.4M521,2771.49%
MAMASTERCARD INCORPORATED$461.4M923,4051.32%
METAMETA PLATFORMS INC$412.9M721,7201.18%
FASTFASTENAL CO$342.1M7,373,7070.98%
RSPINVESCO EXCHANGE TRADED FD T$322.5M1,680,6040.92%
APHAMPHENOL CORP$318.4M2,520,3190.91%
IVVISHARES TR$317.4M485,8390.91%
VEUVANGUARD INTL EQUITY INDEX F$313.1M4,168,6250.90%
LLYELI LILLY & CO$298.0M324,0180.85%
WMTWALMART INC$295.1M2,374,2820.85%
BWXTBWX TECHNOLOGIES INC$294.1M1,438,1250.84%
ABBVABBVIE INC$290.2M1,334,1090.83%
AVGOBROADCOM INC$284.2M918,3280.81%
SYKSTRYKER CORPORATION$278.5M847,7010.80%
ICEINTERCONTINENTAL EXCHANGE IN$250.6M1,593,6280.72%
HDHOME DEPOT INC$250.4M761,4190.72%
VEAVANGUARD TAX-MANAGED FDS$247.5M3,862,0860.71%
DHRDANAHER CORP DEL$245.9M1,296,8040.70%
PGRPROGRESSIVE CORP$241.8M1,219,7490.69%
VOOVANGUARD INDEX FDS$237.5M397,3800.68%
BRK/BBERKSHIRE HATHAWAY INC DEL$237.4M495,3220.68%
UBERUBER TECHNOLOGIES INC$237.3M3,299,5960.68%
JNJJOHNSON & JOHNSON$233.6M955,6320.67%
ECLECOLAB INC$230.5M866,4110.66%
VTVVANGUARD INDEX FDS$228.8M1,165,9120.66%
WSOWATSCO INC$212.0M582,7000.61%
AXPAMERICAN EXPRESS CO$209.9M693,7670.60%
PANWPALO ALTO NETWORKS INC$209.2M1,304,8580.60%
ISRGINTUITIVE SURGICAL INC$196.0M425,2280.56%
TDGTRANSDIGM GROUP INC$192.7M166,2480.55%
NOWSERVICENOW INC$188.3M1,800,9880.54%
VEEVVEEVA SYS INC$187.5M1,067,5760.54%
BABOEING CO$183.5M922,1020.53%
QQQINVESCO QQQ TR$179.5M311,0160.51%
PEVERPURE INC$172.3M2,918,0460.49%
NFLXNETFLIX INC.$169.6M1,763,4510.49%
GLDSPDR GOLD TR$166.4M386,7350.48%
CTASCINTAS CORP$164.7M973,5530.47%
EXMOCEXXON MOBIL CORP$160.6M946,3860.46%
IWMISHARES TR$155.8M628,2280.45%
CVXCHEVRON CORPORATION$148.1M715,9860.42%
VIGVANGUARD SPECIALIZED FUNDS$147.9M687,7710.42%
GWREGUIDEWIRE SOFTWARE INC$145.9M975,2960.42%
ANETARISTA NETWORKS INC$141.3M1,151,2270.41%
ABTABBOTT LABORATORIES$136.3M1,327,7610.39%
AONAON PLC$136.1M421,6050.39%
BXBLACKSTONE INC$135.5M1,178,6120.39%
CPRTCOPART INC$135.2M4,070,9900.39%
AAONAAON INC$134.2M1,622,2030.38%
GSGOLDMAN SACHS GROUP INC$132.2M156,2650.38%
PGPROCTER & GAMBLE CO$129.1M893,9330.37%
IBMINTERNATIONAL BUSINESS MACHS$125.7M518,4570.36%
UNPUNION PAC CORP$124.9M514,8290.36%
PWRQUANTA SVCS INC$124.0M225,8500.36%
DXCMDEXCOM INC$121.0M1,927,3870.35%
ROLROLLINS INC$121.0M2,265,0130.35%
VTIVANGUARD INDEX FDS$119.5M372,3710.34%
IUSVISHARES TR$119.2M1,165,9520.34%
RBCRBC BEARINGS INC$118.3M217,8330.34%
LINLINDE PLC$115.6M233,1820.33%
CWCURTISS WRIGHT CORP$113.8M167,0270.33%
IWFISHARES TR$113.4M266,0260.33%
MUMICRON TECHNOLOGY INC$112.3M332,3110.32%
WMWASTE MGMT INC DEL$111.3M484,3030.32%
TSLATESLA INC$110.1M296,0410.32%
VUGVANGUARD INDEX FDS$109.4M250,4300.31%
MRKMERCK & CO INC$108.5M901,7890.31%
MCDMCDONALDS CORP$108.2M348,2430.31%
KOCOCA COLA CO$107.7M1,415,7350.31%
JLLJONES LANG LASALLE INC$102.7M337,4170.29%
ORLYOREILLY AUTOMOTIVE INC$101.9M1,104,4000.29%
ROKROCKWELL AUTOMATION INC$101.9M284,0670.29%
LYVLIVE NATION ENTERTAINMENT IN$101.0M662,0810.29%
GDGENERAL DYNAMICS CORP$100.2M292,0350.29%
CRWDCROWDSTRIKE HLDGS INC$98.5M252,3790.28%
AMEAMETEK INC$98.1M457,4470.28%
ZTSZOETIS INC$94.0M795,2970.27%
ITWILLINOIS TOOL WKS INC$93.8M360,3200.27%
EFAISHARES TR$93.1M958,8050.27%
HEIHEICO CORP NEW$92.4M336,7990.26%
FANGDIAMONDBACK ENERGY INC$88.1M445,3380.25%
NDAQNASDAQ INC$87.1M1,026,0100.25%
TMOTHERMO FISHER SCIENTIFIC INC$85.0M172,9530.24%
PEPPEPSICO INC$84.9M546,5660.24%
SBUXSTARBUCKS CORP$84.1M938,5480.24%
CATCATERPILLAR INC$84.0M118,5010.24%
SCHWSCHWAB CHARLES CORP$83.7M890,3450.24%
IEFAISHARES TR$83.6M922,9760.24%
DEDEERE & CO$83.2M147,6230.24%
ITOTISHARES TR$82.3M577,4960.24%
AMTAMERICAN TOWER CORP$81.1M470,1280.23%
TYLTYLER TECHNOLOGIES INC$77.8M227,3780.22%
SHOPSHOPIFY INC$74.4M627,4240.21%
RTXRTX CORPORATION$74.2M384,6270.21%
IUSGISHARES TR$74.2M478,2780.21%
IRTCIRHYTHM HOLDINGS INC$74.2M628,3850.21%
CRMSALESFORCE INC$72.6M389,0080.21%
VRSKVERISK ANALYTICS INC$72.1M380,1060.21%
IWVISHARES TR$72.0M194,2400.21%
MRVLMARVELL TECHNOLOGY INC$71.7M723,9760.21%
WABWABTEC$70.9M283,8590.20%
MCKMCKESSON CORP$69.3M80,0420.20%
GNRCGENERAC HLDGS INC$67.7M346,8300.19%
HONGBPHONEYWELL INTL INC$66.9M295,8310.19%
MDBMONGODB INC$66.3M270,9820.19%
INTUINTUIT$66.0M152,5540.19%
ACNACCENTURE PLC IRELAND$64.7M326,0730.19%
CSCOCISCO SYS INC$63.9M823,8010.18%
TJXTJX COS INC NEW$63.0M394,6460.18%
QCOMQUALCOMM INC$62.7M486,9690.18%
ULSUL SOLUTIONS INC$62.2M725,6720.18%
SPGIS&P GLOBAL INC$60.9M143,2230.17%
LOWLOWES COS INC$60.6M256,4140.17%
CMECME GROUP INC$60.4M204,5340.17%
RDVYFIRST TR EXCHANGE TRADED FD$60.1M880,8230.17%
GWWWW GRAINGER INC$59.4M54,4180.17%
SDVYFIRST TR EXCHANGE TRADED FD$58.4M1,480,5580.17%
GEGE AEROSPACE$57.2M201,5090.16%
BLKBLACKROCK INC$57.0M59,2880.16%
APPAPPLOVIN CORP$55.7M139,9510.16%
IWDISHARES TR$55.5M259,6480.16%
RYANRYAN SPECIALTY HOLDINGS INC$55.4M1,641,5800.16%
EPDENTERPRISE PRODS PARTNERS L$55.0M1,454,3570.16%
AMGNAMGEN INC$54.9M155,9980.16%
RBARB GLOBAL INC$54.7M570,3870.16%
ALLALLSTATE CORP$53.7M258,7790.15%
MSIMOTOROLA SOLUTIONS INC$53.3M122,7430.15%
MDLNMEDLINE INC$51.9M1,165,4300.15%
ORCLORACLE CORP$51.7M351,1040.15%
EMREMERSON ELEC CO$51.1M389,9900.15%
BACBANK AMERICA CORP$50.8M1,042,1030.15%
IJRISHARES TR$50.1M402,7920.14%
COINCOINBASE GLOBAL INC$49.7M284,7900.14%
SPMDSPDR SERIES TRUST$49.7M838,8050.14%
GILDGILEAD SCIENCES INC$47.4M340,3450.14%
KLACKLA CORP$47.2M32,0800.14%
IAUISHARES GOLD TR$46.7M530,1610.13%
MDYSTATE STR SPDR S&P MIDCAP 40$46.7M75,6770.13%
TSMTAIWAN SEMICONDUCTOR MANUFAC$46.6M137,7550.13%

This table is the 150 largest positions by value, out of 1,922 reported. The search box only searches what is on this page — a name absent from it may still be in the filing further down the book. The full info table is here.

Rows are aggregated by CUSIP — a manager files the same security multiple times when different internal desks hold it. Tickers link to our own backtest of that asset where we cover it.

Read the original

This page was built from one document: the 2026-03-31 Form 13F info table filed by BLAIR WILLIAM & CO/IL (CIK 902367, accession 0001104659-26-057897). Every other 13F site is reading the same file.

If anything here disagrees with it, the filing wins — and we would want to know. All 13F filings by this manager

What a 13F cannot show you

A 13F is a long-only equity snapshot, and the holes in it are structural. Anyone selling you this data as "what the smart money is doing" is selling you one leg of a position:

  • No short positions. None, ever. A fund shown here as bullish may be net short the same name through a book you cannot see.
  • No cash, bonds, FX, commodities or non-US listings. A macro fund's entire thesis can be invisible.
  • No intra-quarter round trips. Bought and sold inside the same quarter means it never appears at all.
  • Options are notional, not ownership. We keep puts and calls in a separate bucket rather than adding their notional into a fund's book size, which is how a $2B fund gets reported as a $20B one.
  • Confidential treatment. Managers can ask the SEC to withhold a position while they build it. Those holdings are legally absent from the filing, so a "new" position may be months old.

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