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William Blair & Company

William Blair & Company Portfolio holdings

AUM $34.9B
1-Year Est. Return 18.88%
This Fund
S&P 500
This Quarter Est. Return
+1.73%
1 Year Est. Return
+18.88%
3 Year Est. Return
+73.84%
5 Year Est. Return
+90.13%
10 Year Est. Return
+563.35%
AUM
$37.3B
AUM Growth
-$310M
Cap. Flow
-$212M
Cap. Flow %
-0.57%
Top 10 Hldgs %
27.41%
Holding
1,963
New
120
Increased
759
Reduced
753
Closed
96

Top Buys

Rank Stock Value
1
BWXT icon
BWX Technologies
BWXT
+$46.6M
2
META icon
Meta Platforms (Facebook)
META
+$38.3M
3
NOW icon
ServiceNow
NOW
+$37.6M
4
VEU icon
Vanguard FTSE All-World ex-US ETF
VEU
+$32.4M
5
GLD icon
SPDR Gold Trust
GLD
+$29.4M

Top Sells

Rank Stock Value
1
FISV
Fiserv Inc
FISV
+$114M
2
CSGP icon
CoStar Group
CSGP
+$78.3M
3
CWAN
Clearwater Analytics
CWAN
+$75.3M
4
POOL icon
Pool Corp
POOL
+$54M
5
ZTS icon
Zoetis
ZTS
+$51.3M

Sector Composition

Rank Sector Weight
1 Technology 25.8%
2 Financials 13.4%
3 Industrials 12.04%
4 Healthcare 11.22%
5 Communication Services 7.63%
Name Market Value Portfolio Weight Shares or Principal Change
in Stake 		Capital Flow
CPRT icon
51
Copart
CPRT
$27.5B
$173M 0.46%
4,414,974
-323,592
-7% -$13.4M
QQQ icon
52
Invesco QQQ Trust
QQQ
$481B
$173M 0.46%
281,300
+15,715
+6% +$9.64M
VTV icon
53
Vanguard Morningstar Value ETF
VTV
$192B
$172M 0.46%
898,024
+93,718
+12% +$17.6M
INTU icon
54
Intuit
INTU
$89B
$162M 0.43%
243,875
-6,411
-3% -$4.24M
VIG icon
55
Vanguard Dividend Appreciation ETF
VIG
$114B
$148M 0.4%
673,554
+6,943
+1% +$1.52M
ANET icon
56
Arista Networks
ANET
$238B
$147M 0.4%
1,124,560
+11,992
+1% +$1.65M
BA icon
57
Boeing
BA
$185B
$147M 0.4%
678,587
+13,581
+2% +$2.79M
CRM icon
58
Salesforce
CRM
$158B
$146M 0.39%
552,086
-62,609
-10% -$15.6M
NFLX icon
59
Netflix
NFLX
$309B
$140M 0.38%
1,495,695
+3,375
+0.2% +$364K
IBM icon
60
IBM
IBM
$224B
$140M 0.37%
471,447
+11,707
+3% +$3.51M
IWM icon
61
iShares Russell 2000 ETF
IWM
$81.9B
$138M 0.37%
558,738
+58,277
+12% +$14.3M
GS icon
62
Goldman Sachs
GS
$303B
$136M 0.37%
155,003
+1,797
+1% +$1.47M
CSGP icon
63
CoStar Group
CSGP
$12.3B
$136M 0.37%
2,023,523
-1,104,950
-35% -$78.3M
ROL icon
64
Rollins
ROL
$18.2B
$136M 0.36%
2,260,758
+136,269
+6% +$8M
DXCM icon
65
DexCom
DXCM
$32B
$132M 0.35%
1,988,841
-120,502
-6% -$7.79M
TSLA icon
66
Tesla
TSLA
$1.3T
$132M 0.35%
293,483
+25,468
+10% +$11.3M
RYAN icon
67
Ryan Specialty Holdings
RYAN
$11B
$130M 0.35%
2,522,471
-138,320
-5% -$7.59M
AAON icon
68
Aaon
AAON
$7.77B
$128M 0.34%
1,679,025
-140,267
-8% -$13M
IRTC icon
69
iRhythm Holdings
IRTC
$4.2B
$128M 0.34%
718,797
-21,924
-3% -$3.89M
PG icon
70
Procter & Gamble
PG
$339B
$125M 0.33%
868,968
-59,429
-6% -$8.76M
IWF icon
71
iShares Russell 1000 Growth ETF
IWF
$128B
$124M 0.33%
1,052,072
+48,880
+5% +$5.79M
MDB icon
72
MongoDB
MDB
$32.1B
$123M 0.33%
293,886
-6,124
-2% -$2.23M
ZTS icon
73
Zoetis
ZTS
$30B
$122M 0.33%
969,963
-393,192
-29% -$51.3M
VUG icon
74
Vanguard Morningstar Growth ETF
VUG
$230B
$122M 0.33%
1,499,376
+286,020
+24% +$23.2M
AMT icon
75
American Tower
AMT
$80.4B
$119M 0.32%
678,244
-103,804
-13% -$18.9M
1 2
3
4 5

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William Blair & Company's Q4 2025 Portfolio in Review

As of Q4 2025, William Blair & Company held 1,963 positions worth $37.3B, down 0.82% from $37.6B the previous quarter. Its ten largest holdings account for 27% of the portfolio.

William Blair & Company's Q4 2025 filing shows 120 new, 759 increased, 753 reduced and 96 closed positions. Its largest new stake was Wingstop: 90,773 shares worth $21.6M. The largest sale was Fiserv Inc, an estimated $114M.

By sector, the portfolio is most concentrated in Technology at 26% of assets, down from 27% a quarter earlier, followed by Financials and Industrials.

  • William Blair & Company's largest Q4 2025 buy was Wingstop: 90,773 shares worth $21.6M.
  • William Blair & Company added most to BWX Technologies in Q4 2025, an estimated $46.6M increase.
  • William Blair & Company's biggest Q4 2025 reduction was Fiserv Inc, cutting an estimated $114M.
  • William Blair & Company fully exited SAP in Q4 2025, selling an estimated $9.19M.
  • William Blair & Company's ten largest holdings make up 27% of its $37.3B portfolio in Q4 2025.
  • William Blair & Company opened 120 new positions and closed 96 in Q4 2025.
  • William Blair & Company's portfolio value fell 0.82% quarter-over-quarter to $37.3B.

Based on William Blair & Company's 13F filing for Q4 2025, filed 17 Feb 2026.