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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
VB icon
276
Vanguard Morningstar Small-Cap ETF
VB
$82.5B
$15.7M 0.04%
60,762
+1,162
+2% +$298K
CB icon
277
Chubb
CB
$134B
$15.5M 0.04%
49,733
+993
+2% +$290K
CBOE icon
278
Cboe Global Markets
CBOE
$30.4B
$15.3M 0.04%
60,820
-414
-0.7% -$103K
VMI icon
279
Valmont Industries
VMI
$9.55B
$15.3M 0.04%
37,938
-1,922
-5% -$782K
PCTY icon
280
Paylocity
PCTY
$7.9B
$15.1M 0.04%
98,913
-1,466
-1% -$218K
BLBD icon
281
Blue Bird Corp
BLBD
$2.04B
$15.1M 0.04%
320,653
-319
-0.1% -$16.7K
KNSL icon
282
Kinsale Capital Group
KNSL
$8.38B
$15M 0.04%
38,464
-899
-2% -$367K
KMB icon
283
Kimberly-Clark
KMB
$36.1B
$15M 0.04%
148,979
+6,886
+5% +$753K
XYZ
284
Block Inc
XYZ
$47.8B
$14.9M 0.04%
229,226
-48,419
-17% -$3.34M
VKTX icon
285
Viking Therapeutics
VKTX
$4B
$14.9M 0.04%
423,964
+68,038
+19% +$2.41M
BILL icon
286
BILL Holdings
BILL
$4.84B
$14.9M 0.04%
272,742
-13,898
-5% -$714K
AGG icon
287
iShares Core US Aggregate Bond ETF
AGG
$138B
$14.7M 0.04%
147,215
+19,646
+15% +$1.97M
CYBR
288
DELISTED
CyberArk
CYBR
$14.5M 0.04%
32,592
-2,929
-8% -$1.41M
TW icon
289
Tradeweb Markets
TW
$21.9B
$14.5M 0.04%
135,033
-11,869
-8% -$1.27M
SYY icon
290
Sysco
SYY
$40.3B
$14.5M 0.04%
196,199
-11,706
-6% -$891K
IWR icon
291
iShares Russell Mid-Cap ETF
IWR
$57.5B
$14.1M 0.04%
146,668
+9,444
+7% +$908K
CHD icon
292
Church & Dwight Co
CHD
$24.5B
$14.1M 0.04%
167,996
+31,804
+23% +$2.72M
LULU icon
293
lululemon athletica
LULU
$14.4B
$14.1M 0.04%
67,756
-6,935
-9% -$1.26M
FROG icon
294
JFrog
FROG
$10.7B
$14M 0.04%
224,374
-37,931
-14% -$2.16M
SPYM
295
State Street SPDR Portfolio S&P 500 ETF
SPYM
$169B
$13.9M 0.04%
173,758
+51,290
+42% +$4.08M
WCN
296
Waste Connections
WCN
$41.9B
$13.7M 0.04%
78,181
-7,286
-9% -$1.26M
INTC icon
297
Intel
INTC
$496B
$13.6M 0.04%
369,396
+17,624
+5% +$665K
JEPI icon
298
JPMorgan Equity Premium Income ETF
JEPI
$46B
$13.6M 0.04%
237,203
+7,220
+3% +$412K
RKLB icon
299
Rocket Lab Corp
RKLB
$50.7B
$13.5M 0.04%
193,469
-6,849
-3% -$393K
TECH icon
300
Bio-Techne
TECH
$11.2B
$13.5M 0.04%
228,812
+78,723
+52% +$4.78M
10 11
12
13 14

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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.