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
-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
AAPL icon
1
Apple
AAPL
$4.79T
$1.51B 4.31%
5,930,914
-19,034
-0.3% -$4.95M
MSFT icon
2
Microsoft
MSFT
$2.9T
$1.29B 3.71%
3,498,110
-76,458
-2% -$32M
AMZN icon
3
Amazon
AMZN
$2.63T
$1.26B 3.62%
6,057,938
-6,486
-0.1% -$1.43M
NVDA icon
4
NVIDIA
NVDA
$5.14T
$947M 2.71%
5,427,875
-66,475
-1% -$12.2M
GOOG icon
5
Alphabet (Google) Class C
GOOG
$4.17T
$871M 2.5%
3,035,765
-82,994
-3% -$26.1M
GOOGL icon
6
Alphabet (Google) Class A
GOOGL
$4.17T
$701M 2.01%
2,436,117
-57,463
-2% -$18.1M
JPM icon
7
JPMorgan Chase
JPM
$926B
$679M 1.94%
2,307,253
-2,556
-0.1% -$776K
GEV icon
8
GE Vernova
GEV
$262B
$580M 1.66%
664,603
+12,297
+2% +$9.59M
V icon
9
Visa
V
$672B
$558M 1.6%
1,844,583
-84,654
-4% -$27.2M
SPY icon
10
State Street SPDR S&P 500 ETF Trust
SPY
$787B
$550M 1.58%
845,294
-12,509
-1% -$8.5M
IDXX icon
11
Idexx Laboratories
IDXX
$43B
$532M 1.52%
946,336
-55,039
-5% -$35.3M
COST icon
12
Costco
COST
$411B
$519M 1.49%
521,277
+95
+0% +$92.6K
MA icon
13
Mastercard
MA
$470B
$461M 1.32%
923,405
-31,783
-3% -$16.7M
META icon
14
Meta Platforms (Facebook)
META
$1.59T
$413M 1.18%
721,720
-14,482
-2% -$9.28M
FAST icon
15
Fastenal
FAST
$52B
$342M 0.98%
7,373,707
+359,041
+5% +$16.1M
RSP icon
16
Invesco S&P 500 Equal Weight ETF
RSP
$95.7B
$323M 0.92%
1,680,604
+1,130,618
+206% +$224M
APH icon
17
Amphenol
APH
$194B
$318M 0.91%
2,520,319
-133,572
-5% -$18.8M
IVV icon
18
iShares Core S&P 500 ETF
IVV
$886B
$317M 0.91%
485,839
-2,581
-0.5% -$1.76M
VEU icon
19
Vanguard FTSE All-World ex-US ETF
VEU
$66.5B
$313M 0.9%
4,168,625
+1,457,190
+54% +$113M
LLY icon
20
Eli Lilly
LLY
$1.04T
$298M 0.85%
324,018
-778
-0.2% -$789K
WMT icon
21
Walmart Inc
WMT
$870B
$295M 0.85%
2,374,282
-38,302
-2% -$4.7M
BWXT icon
22
BWX Technologies
BWXT
$16B
$294M 0.84%
1,438,125
-1,541
-0.1% -$313K
ABBV icon
23
AbbVie
ABBV
$448B
$290M 0.83%
1,334,109
-3,352
-0.3% -$744K
AVGO icon
24
Broadcom
AVGO
$1.89T
$284M 0.81%
918,328
+21,882
+2% +$7.2M
SYK icon
25
Stryker
SYK
$119B
$279M 0.8%
847,701
+2,802
+0.3% +$1.01M
1
2 3 4 5

Similar funds

SAM
Storebrand Asset Management Lysaker, Norway $34.8B AUM 25.49% 1-Year Est. Return
Daiwa Securities Group
Daiwa Securities Group Tokyo, Japan $34.8B AUM 20.7% 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
Parnassus Investments
Parnassus Investments San Francisco, California $34.1B AUM 20.22% 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

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.