We are live on ! Find out more
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
CACI icon
301
CACI
CACI
$14.3B
$13.4M 0.04%
25,234
+6,000
+31% +$3.39M
MMM icon
302
3M
MMM
$93.7B
$13.3M 0.04%
82,906
-4,378
-5% -$716K
BKNG icon
303
Booking.com
BKNG
$159B
$13.2M 0.04%
61,700
-4,975
-7% -$1.02M
MGK icon
304
Vanguard Morningstar Mega Cap Growth ETF
MGK
$33.9B
$13.2M 0.04%
159,870
+26,685
+20% +$2.19M
SBAC icon
305
SBA Communications
SBAC
$19.2B
$13.2M 0.04%
68,211
-3,561
-5% -$688K
ASML icon
306
ASML
ASML
$674B
$13.1M 0.04%
12,271
+8
+0.1% +$8.35K
FIS icon
307
Fidelity National Information Services
FIS
$21.9B
$13.1M 0.04%
196,910
-91,712
-32% -$6.05M
EXAS
308
DELISTED
Exact Sciences
EXAS
$13.1M 0.04%
128,517
-10,977
-8% -$882K
MCO icon
309
Moody's
MCO
$83.1B
$13M 0.03%
25,354
-219
-0.9% -$107K
WPM icon
310
Wheaton Precious Metals
WPM
$60.2B
$12.8M 0.03%
108,843
+251
+0.2% +$26.9K
EFV icon
311
iShares MSCI EAFE Value ETF
EFV
$30B
$12.8M 0.03%
179,104
+9,587
+6% +$666K
FTNT icon
312
Fortinet
FTNT
$120B
$12.8M 0.03%
160,633
-26,212
-14% -$2.17M
VXUS icon
313
Vanguard Total International Stock ETF
VXUS
$162B
$12.7M 0.03%
168,572
+16,015
+10% +$1.2M
ABNB icon
314
Airbnb
ABNB
$110B
$12.6M 0.03%
92,708
-4,536
-5% -$565K
YETI icon
315
Yeti Holdings
YETI
$3.93B
$12.6M 0.03%
284,362
-62,330
-18% -$2.4M
XBI icon
316
State Street SPDR S&P Biotech ETF
XBI
$10.3B
$12.5M 0.03%
102,867
+1,057
+1% +$121K
APPF icon
317
AppFolio
APPF
$7.06B
$12.5M 0.03%
53,626
-634
-1% -$151K
VBR icon
318
Vanguard Morningstar Small-Cap Value ETF
VBR
$37.9B
$12.4M 0.03%
58,483
+6,262
+12% +$1.31M
MPWR icon
319
Monolithic Power Systems
MPWR
$68.4B
$12.4M 0.03%
13,647
+3,465
+34% +$3.33M
ADI icon
320
Analog Devices
ADI
$189B
$12.2M 0.03%
45,133
+712
+2% +$179K
NSC icon
321
Norfolk Southern
NSC
$75.5B
$12.2M 0.03%
42,242
-446
-1% -$129K
IWO icon
322
iShares Russell 2000 Growth ETF
IWO
$14.9B
$12.2M 0.03%
37,644
-1,511
-4% -$491K
STWD icon
323
Starwood Property Trust
STWD
$6.06B
$12.1M 0.03%
674,462
+27,438
+4% +$505K
DOCU
324
DocuSign
DOCU
$11.5B
$12M 0.03%
175,214
-98,526
-36% -$6.81M
VNQ icon
325
Vanguard Real Estate ETF
VNQ
$38.5B
$11.9M 0.03%
134,460
-12,044
-8% -$1.08M
11 12
13
14 15

Similar funds

SAM
Storebrand Asset Management Lysaker, Norway $34.8B AUM 25.49% 1-Year Est. Return
Chevy Chase Trust
Chevy Chase Trust Bethesda, Maryland $34.7B AUM 29.45% 1-Year Est. Return
VIA
Vanguard Investments Australia Victoria, Australia $34.6B AUM
Alyeska Investment Group
Alyeska Investment Group Chicago, Illinois $35.4B AUM 33.54% 1-Year Est. Return
Pacer Advisors
Pacer Advisors Malvern, Pennsylvania $35.6B AUM 18.19% 1-Year Est. Return
Kayne Anderson Rudnick Investment Management
Kayne Anderson Rudnick Investment Management Los Angeles, California $34B AUM 6.31% 1-Year Est. Return
Viking Global Investors
Viking Global Investors Stamford, Connecticut $35.7B AUM 21.3% 1-Year Est. Return
First Manhattan
First Manhattan New York $36.1B AUM 11.5% 1-Year Est. Return

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.