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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
-3.16%
1 Year Est. Return
+18.88%
3 Year Est. Return
+73.84%
5 Year Est. Return
+90.13%
10 Year Est. Return
+512.03%
AUM
$34.9B
AUM Growth
-$2.36B
Cap. Flow
-$465K
Cap. Flow %
-0%
Top 10 Hldgs %
25.64%
Holding
2,019
New
132
Increased
799
Reduced
746
Closed
97

Top Buys

Rank Stock Value
1
RSP icon
Invesco S&P 500 Equal Weight ETF
RSP
+$224M
2
VEU icon
Vanguard FTSE All-World ex-US ETF
VEU
+$113M
3
PWR icon
Quanta Services
PWR
+$75M
4
GLD icon
SPDR Gold Trust
GLD
+$58.9M
5
BA icon
Boeing
BA
+$55.5M

Top Sells

Rank Stock Value
1
WDAY icon
Workday
WDAY
+$91.2M
2
CWAN
Clearwater Analytics
CWAN
+$78M
3
APP icon
Applovin
APP
+$74.7M
4
TYL icon
Tyler Technologies
TYL
+$69.1M
5
UBER icon
Uber
UBER
+$62.2M

Sector Composition

Rank Sector Weight
1 Technology 21.79%
2 Industrials 14.2%
3 Financials 12.26%
4 Healthcare 10.59%
5 Consumer Discretionary 7.17%
Name Market Value Portfolio Weight Shares or Principal Change
in Stake 		Capital Flow
BSX icon
851
Boston Scientific
BSX
$68.4B
$1.32M ﹤0.01%
21,040
-95,658
-82% -$7.65M
OSK icon
852
Oshkosh
OSK
$8.82B
$1.32M ﹤0.01%
8,960
+3
+0% +$468
DRS icon
853
Leonardo DRS
DRS
$12.4B
$1.32M ﹤0.01%
29,613
+1,126
+4% +$47.5K
BMO icon
854
Bank of Montreal
BMO
$123B
$1.31M ﹤0.01%
9,697
+2,354
+32% +$327K
QTEC icon
855
First Trust NASDAQ-100 Technology Index Fund
QTEC
$4.33B
$1.31M ﹤0.01%
6,066
– –
AIG icon
856
American International
AIG
$42.5B
$1.3M ﹤0.01%
17,333
+218
+1% +$16.7K
ENS icon
857
EnerSys
ENS
$6.43B
$1.3M ﹤0.01%
7,461
-83
-1% -$14.1K
BJUL icon
858
Innovator US Equity Buffer ETF July
BJUL
$340M
$1.29M ﹤0.01%
26,048
-2,482
-9% -$126K
STT icon
859
State Street
STT
$48.4B
$1.29M ﹤0.01%
10,217
+199
+2% +$25.5K
MGM icon
860
MGM Resorts International
MGM
$11.7B
$1.29M ﹤0.01%
34,767
+413
+1% +$14.7K
AMTM
861
Amentum Holdings
AMTM
$5.33B
$1.29M ﹤0.01%
49,298
-30,667
-38% -$962K
VITL icon
862
Vital Farms
VITL
$586M
$1.29M ﹤0.01%
91,015
+33,619
+59% +$795K
PPH icon
863
VanEck Pharmaceutical ETF
PPH
$985M
$1.28M ﹤0.01%
12,342
– –
HAS icon
864
Hasbro
HAS
$13.5B
$1.28M ﹤0.01%
13,688
-96
-0.7% -$8.96K
HII icon
865
Huntington Ingalls Industries
HII
$11B
$1.27M ﹤0.01%
3,346
+542
+19% +$223K
GUNR icon
866
FlexShares Global Upstream Natural Resources Index Fund
GUNR
$7.19B
$1.27M ﹤0.01%
23,014
-876
-4% -$45.7K
XLRE icon
867
State Street Real Estate Select Sector SPDR ETF
XLRE
$8.72B
$1.27M ﹤0.01%
31,048
+6,574
+27% +$276K
HPE icon
868
Hewlett Packard
HPE
$58.8B
$1.26M ﹤0.01%
52,919
+1,370
+3% +$30.4K
LSCC icon
869
Lattice Semiconductor
LSCC
$16B
$1.26M ﹤0.01%
13,573
-5
-0% -$448
CRDO icon
870
Credo Technology Group
CRDO
$33.1B
$1.26M ﹤0.01%
13,407
+9,759
+268% +$1.19M
LNT icon
871
Alliant Energy
LNT
$18.6B
$1.25M ﹤0.01%
17,455
-653
-4% -$45.1K
SSNC icon
872
SS&C Technologies
SSNC
$18.9B
$1.25M ﹤0.01%
18,533
-99,588
-84% -$7.66M
ELV icon
873
Elevance Health
ELV
$81.5B
$1.25M ﹤0.01%
4,273
-756
-15% -$248K
A icon
874
Agilent Technologies
A
$39.6B
$1.24M ﹤0.01%
10,861
-9,860
-48% -$1.25M
RELY icon
875
Remitly
RELY
$4.9B
$1.23M ﹤0.01%
78,259
-3,626
-4% -$53.7K
33 34
35
36 37

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William Blair & Company's Q1 2026 Portfolio in Review

As of Q1 2026, William Blair & Company held 2,019 positions worth $34.9B, down 6.3% from $37.3B the previous quarter. Its ten largest holdings account for 26% of the portfolio.

William Blair & Company's Q1 2026 filing shows 132 new, 799 increased, 746 reduced and 97 closed positions. Its largest new stake was Silicon Motion: 103,179 shares worth $11.6M. The largest sale was Workday, an estimated $91.2M.

By sector, the portfolio is most concentrated in Technology at 22% of assets, down from 26% a quarter earlier, followed by Industrials and Financials.

  • William Blair & Company's largest Q1 2026 buy was Silicon Motion: 103,179 shares worth $11.6M.
  • William Blair & Company added most to Invesco S&P 500 Equal Weight ETF in Q1 2026, an estimated $224M increase.
  • William Blair & Company's biggest Q1 2026 reduction was Workday, cutting an estimated $91.2M.
  • William Blair & Company fully exited Dynavax Technologies in Q1 2026, selling an estimated $27.4M.
  • William Blair & Company's ten largest holdings make up 26% of its $34.9B portfolio in Q1 2026.
  • William Blair & Company opened 132 new positions and closed 97 in Q1 2026.
  • William Blair & Company's portfolio value fell 6.3% quarter-over-quarter to $34.9B.

Based on William Blair & Company's 13F filing for Q1 2026, filed 8 May 2026.