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William Blair Investment Management

William Blair Investment Management Portfolio holdings

AUM $33.3B
1-Year Est. Return 44.76%
This Fund
S&P 500
This Quarter Est. Return
+25.48%
1 Year Est. Return
+44.76%
3 Year Est. Return
+140.8%
5 Year Est. Return
+166.51%
10 Year Est. Return
+978.6%
AUM
$30B
AUM Growth
+$4.37B
Cap. Flow
-$974M
Cap. Flow %
-3.24%
Top 10 Hldgs %
17.75%
Holding
375
New
32
Increased
99
Reduced
224
Closed
19

Top Buys

Rank Stock Value
1
TECH icon
Bio-Techne
TECH
+$212M
2
TXG icon
10x Genomics
TXG
+$186M
3
TMX
Terminix Global Holdings, Inc.
TMX
+$126M
4
MMSI icon
Merit Medical Systems
MMSI
+$125M
5
ZEN
ZENDESK INC
ZEN
+$121M

Top Sells

Rank Stock Value
1
IRTC icon
iRhythm Holdings
IRTC
+$255M
2
EXAS
Exact Sciences
EXAS
+$246M
3
TRU icon
TransUnion
TRU
+$166M
4
BN icon
Brookfield
BN
+$112M
5
TSM icon
TSMC
TSM
+$104M

Sector Composition

Rank Sector Weight
1 Technology 26.72%
2 Healthcare 19.58%
3 Industrials 13.65%
4 Consumer Discretionary 13.62%
5 Financials 6.72%
Name Market Value Portfolio Weight Shares or Principal Change
in Stake 		Capital Flow
IDXX icon
126
Idexx Laboratories
IDXX
$45B
$54.7M 0.18%
109,441
-19,543
-15% -$8.74M
BOOT icon
127
Boot Barn
BOOT
$4.87B
$53.9M 0.18%
1,243,302
-563,202
-31% -$21.2M
TMO icon
128
Thermo Fisher Scientific
TMO
$223B
$53.4M 0.18%
114,707
-20,789
-15% -$9.75M
BLK icon
129
Blackrock
BLK
$180B
$53.4M 0.18%
73,977
-17,068
-19% -$11.3M
ICE icon
130
Intercontinental Exchange
ICE
$85B
$48.5M 0.16%
420,305
-96,369
-19% -$10M
APO icon
131
Apollo Global Management
APO
$81.9B
$48.1M 0.16%
982,057
+12,992
+1% +$580K
UNP icon
132
Union Pacific
UNP
$175B
$47.9M 0.16%
229,909
-60,889
-21% -$12.2M
CDXS icon
133
Codexis
CDXS
$172M
$47M 0.16%
2,150,849
-54,459
-2% -$896K
QNST icon
134
QuinStreet
QNST
$1.19B
$46.8M 0.16%
2,184,177
-229,238
-9% -$4.18M
DCO icon
135
Ducommun
DCO
$3.04B
$46.6M 0.16%
868,455
+54,897
+7% +$2.37M
HNGR
136
DELISTED
Hanger Inc.
HNGR
$46.2M 0.15%
2,101,491
+178,187
+9% +$3.65M
ROP icon
137
Roper Technologies
ROP
$39.1B
$46M 0.15%
106,675
-28,261
-21% -$11.6M
GDYN icon
138
Grid Dynamics Holdings
GDYN
$632M
$45.4M 0.15%
3,601,085
+339,438
+10% +$3.28M
CWST icon
139
Casella Waste Systems
CWST
$5.76B
$45.3M 0.15%
730,988
+100,888
+16% +$5.99M
LHCG
140
DELISTED
LHC Group LLC
LHCG
$43.8M 0.15%
205,222
+15,079
+8% +$3.21M
A icon
141
Agilent Technologies
A
$41.9B
$43M 0.14%
362,663
-116,178
-24% -$12.9M
ANET icon
142
Arista Networks
ANET
$266B
$43M 0.14%
2,365,040
-464,640
-16% -$7.36M
VRRM icon
143
Verra Mobility
VRRM
$715M
$42.8M 0.14%
3,187,904
+280,447
+10% +$3.3M
ISRG icon
144
Intuitive Surgical
ISRG
$142B
$42.7M 0.14%
156,624
-30,411
-16% -$7.55M
EW icon
145
Edwards Lifesciences
EW
$53.6B
$41.9M 0.14%
459,687
-70,919
-13% -$5.88M
RSI icon
146
Rush Street Interactive
RSI
$2.81B
$41.2M 0.14%
1,905,288
+550,929
+41% +$8.25M
OEC icon
147
Orion
OEC
$365M
$41.1M 0.14%
2,399,405
-8,310
-0.3% -$127K
PRG icon
148
PROG Holdings
PRG
$1.64B
$41M 0.14%
+760,260
New +$39.2M
SKY icon
149
Champion Homes
SKY
$5.1B
$39.9M 0.13%
1,288,898
+240,620
+23% +$7.09M
TTWO icon
150
Take-Two Interactive
TTWO
$45.4B
$36.8M 0.12%
176,962
-16,834
-9% -$2.94M
4 5
6
7 8

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William Blair Investment Management's Q4 2020 Portfolio in Review

As of Q4 2020, William Blair Investment Management held 375 positions worth $30B, up 17% from $25.7B the previous quarter. Its ten largest holdings account for 18% of the portfolio.

William Blair Investment Management withdrew a net $974M in Q4 2020, closing 19 positions and reducing 224 holdings. Its most notable exit was iRhythm Holdings, an estimated $255M position sold in full.

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

Against the trend, William Blair Investment Management opened a new position in Bio-Techne worth $232M.

  • William Blair Investment Management's largest Q4 2020 buy was Bio-Techne: 2,923,168 shares worth $232M.
  • William Blair Investment Management added most to Terminix Global Holdings, Inc. in Q4 2020, an estimated $126M increase.
  • William Blair Investment Management's biggest Q4 2020 reduction was Exact Sciences, cutting an estimated $246M.
  • William Blair Investment Management fully exited iRhythm Holdings in Q4 2020, selling an estimated $255M.
  • William Blair Investment Management's ten largest holdings make up 18% of its $30B portfolio in Q4 2020.
  • William Blair Investment Management opened 32 new positions and closed 19 in Q4 2020.
  • William Blair Investment Management's portfolio value rose 17% quarter-over-quarter to $30B.

Based on William Blair Investment Management's 13F filing for Q4 2020, filed 9 Feb 2021.