2026 Q2 Portfolio Activity
In 2026 Q2, WESTFIELD CAPITAL MANAGEMENT CO LP maintained a portfolio of 319 distinct positions. The most significant new addition was ASCENDIS PHARMA A/S, now representing 4.18% of the total fund value. They heavily accumulated shares in ALPHABET INC, increasing the position by 85.0%. Conversely, WESTFIELD CAPITAL MANAGEMENT CO LP completely exited their position in ASCENDIS PHARMA A/S.
Position History
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Total Positions
319
Quarter
2026 Q2
Top Holding
NVDA (5.3%)
Top 10 Concentration
29.2%
Turnover Rate
23.4%
Sector HHI
0.18
Items per page:
Showing 1-50 of 319
WESTFIELD CAPITAL MANAGEMENT CO LP Full Holdings List — 2026 Q2
| Stock | History | Sector / Type | Port % | Prev % | Rank / Prev | Conviction | Change | % Change | Influence | Shares | Mkt Value | Avg Cost | Price Held | 1st Owned | Source | Source Date | Date Reported | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
NVDA
NVIDIA CORPORAT...
|
Technology | 5.28% | 4.62% |
#1
Prev: #1
|
6.6 |
—
|
1,762,887 | 27.9% |
P
S
|
8,079,926 | $1,616,712,338 | 2003 Q4 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
GOOGL
ALPHABET INC
|
Communication Services | 4.38% | 2.45% |
#2
5
Prev: #7
|
6.3 |
—
|
1,722,330 | 85.0% |
P
S
|
3,749,074 | $1,339,806,415 | 2015 Q4 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
N/A
ASCENDIS PHARMA...
|
|
Unknown | 4.18% | — |
#3
Prev: #—
|
6.2 |
—
|
4,798,267 | — |
NEW
|
4,798,267 | $1,279,793,795 | — | 13F Filing | 2026-06-30 | 2026-08-12 | ||
|
AXON
AXON ENTERPRISE...
|
Industrials | 2.73% | 1.90% |
#4
7
Prev: #11
|
4.1 |
—
|
427,356 | 40.2% |
P
S
|
1,491,490 | $836,144,444 | 2022 Q4 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
FTAI
FTAI AVIATION L...
|
Industrials | 2.60% | 2.93% |
#5
Prev: #5
|
2.0 |
—
|
89,001 | 3.1% |
P
S
|
2,937,228 | $794,608,199 | 2024 Q2 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
AAPL
APPLE INC
|
Technology | 2.43% | 3.34% |
#6
2
Prev: #4
|
1.5 |
—
|
-559,339 | -17.9% |
P
S
|
2,573,774 | $744,747,287 | 2002 Q2 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
FIX
COMFORT SYS USA...
|
Industrials | 2.30% | 3.59% |
#7
4
Prev: #3
|
0.9 |
—
|
-265,482 | -42.8% |
P
S
|
355,433 | $704,451,409 | 2023 Q4 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
AVGO
BROADCOM INC
|
Technology | 1.92% | 1.61% |
#8
4
Prev: #12
|
3.3 |
—
|
319,597 | 25.8% |
P
S
|
1,556,522 | $587,976,343 | 2016 Q1 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
MSFT
MICROSOFT CORP
|
Technology | 1.72% | 2.56% |
#9
3
Prev: #6
|
1.2 |
—
|
-235,219 | -14.3% |
P
S
|
1,414,294 | $527,559,770 | 2002 Q2 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
HWM
HOWMET AEROSPAC...
|
Industrials | 1.69% | 2.21% |
#10
2
Prev: #8
|
1.2 |
—
|
-368,221 | -16.1% |
P
S
|
1,921,476 | $516,608,027 | 2025 Q1 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
LLY
ELI LILLY & CO
|
Healthcare | 1.63% | 1.41% |
#11
2
Prev: #13
|
2.7 |
—
|
52,153 | 14.3% |
P
S
|
416,732 | $499,840,862 | 2006 Q3 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
SNOW
SNOWFLAKE INC
|
Technology | 1.44% | 0.45% |
#12
51
Prev: #63
|
3.6 |
—
|
1,017,688 | 141.6% |
P
S
|
1,736,498 | $441,938,647 | 2022 Q1 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
MKSI
MKS INC.
|
Technology | 1.35% | 1.01% |
#13
4
Prev: #17
|
1.0 |
—
|
-118,146 | -11.3% |
P
S
|
928,617 | $413,048,645 | 2017 Q3 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
META
META PLATFORMS ...
|
Communication Services | 1.25% | 1.26% |
#14
1
Prev: #15
|
3.0 |
—
|
150,567 | 28.6% |
P
S
|
677,389 | $381,566,445 | 2013 Q3 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
VRT
VERTIV HOLDINGS...
|
Industrials | 1.15% | 2.02% |
#15
6
Prev: #9
|
0.5 |
—
|
-867,335 | -45.1% |
P
S
|
1,054,361 | $353,021,161 | 2023 Q3 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
GEV
GE VERNOVA INC
|
Industrials | 0.93% | 0.73% |
#16
8
Prev: #24
|
2.9 |
—
|
41,966 | 21.1% |
P
S
|
241,272 | $283,461,275 | 2024 Q3 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
MU
MICRON TECHNOLO...
|
Technology | 0.86% | 0.14% |
#17
145
Prev: #162
|
3.3 |
—
|
127,769 | 127.2% |
P
S
|
228,203 | $263,412,188 | 2003 Q3 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
V
VISA INC
|
Financial Services | 0.85% | 0.58% |
#18
24
Prev: #42
|
3.3 |
—
|
305,855 | 67.0% |
P
S
|
762,403 | $261,572,839 | 2008 Q1 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
APG
API GROUP CORP
|
Industrials | 0.85% | 0.79% |
#19
3
Prev: #22
|
2.8 |
—
|
1,519,372 | 32.8% |
P
S
|
6,154,301 | $260,634,647 | 2025 Q4 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
TPR
TAPESTRY INC
|
Consumer Cyclical | 0.81% | 1.30% |
#20
6
Prev: #14
|
0.3 |
—
|
-502,293 | -22.8% |
P
S
|
1,696,569 | $248,343,835 | 2021 Q1 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
RYTM
RHYTHM PHARMACE...
|
Healthcare | 0.80% | 0.70% |
#21
5
Prev: #26
|
2.3 |
—
|
279,472 | 14.5% |
P
S
|
2,208,595 | $245,220,303 | 2025 Q1 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
LTH
LIFE TIME GROUP...
|
Consumer Cyclical | 0.80% | 0.36% |
#22
68
Prev: #90
|
3.3 |
—
|
2,809,739 | 88.2% |
P
S
|
5,995,254 | $244,846,173 | 2026 Q1 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
TSM
TAIWAN SEMICOND...
|
Technology | 0.80% | 0.70% |
#23
4
Prev: #27
|
0.8 |
—
|
17,495 | 3.5% |
P
S
|
510,999 | $244,037,920 | 2019 Q4 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
GH
GUARDANT HEALTH...
|
Healthcare | 0.80% | 0.53% |
#24
27
Prev: #51
|
2.3 |
—
|
261,920 | 19.2% |
P
S
|
1,624,459 | $243,717,584 | 2022 Q1 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
PWR
QUANTA SVCS INC
|
Industrials | 0.78% | 0.76% |
#25
2
Prev: #23
|
0.8 |
—
|
-327 | -0.1% |
P
S
|
331,489 | $238,685,542 | 2025 Q2 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
NOW
SERVICENOW INC
|
Technology | 0.77% | 0.61% |
#26
12
Prev: #38
|
3.3 |
—
|
979,524 | 70.3% |
P
S
|
2,373,711 | $235,661,989 | 2013 Q4 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
AMD
ADVANCED MICRO ...
|
Technology | 0.76% | 0.00% |
#27
199
Prev: #226
|
3.3 |
—
|
398,061 | 7929.5% |
P
S
|
403,081 | $234,153,542 | 2002 Q2 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
PANW
PALO ALTO NETWO...
|
Technology | 0.73% | 0.43% |
#28
43
Prev: #71
|
0.8 |
—
|
21,848 | 3.4% |
P
S
|
658,331 | $224,504,060 | 2014 Q2 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
WWD
WOODWARD INC
|
Industrials | 0.73% | 0.41% |
#29
46
Prev: #75
|
3.3 |
—
|
254,320 | 93.4% |
P
S
|
526,505 | $223,996,287 | 2019 Q2 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
ANET
ARISTA NETWORKS...
|
Technology | 0.73% | 0.40% |
#30
46
Prev: #76
|
3.3 |
—
|
536,694 | 68.8% |
P
S
|
1,317,096 | $223,748,310 | 2018 Q3 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
LPLA
LPL FINL HLDGS ...
|
Financial Services | 0.73% | 1.11% |
#31
15
Prev: #16
|
0.8 |
—
|
-88,445 | -10.0% |
P
S
|
793,061 | $223,389,290 | 2013 Q4 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
RKLB
ROCKET LAB CORP
|
Industrials | 0.70% | 0.85% |
#32
12
Prev: #20
|
0.3 |
—
|
-1,058,606 | -33.4% |
P
S
|
2,114,005 | $214,888,621 | 2024 Q4 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
AS
AMER SPORTS INC
|
Consumer Cyclical | 0.70% | 0.54% |
#33
15
Prev: #48
|
3.3 |
—
|
2,407,402 | 61.1% |
P
S
|
6,344,923 | $214,712,179 | 2026 Q1 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
NET
CLOUDFLARE INC
|
Technology | 0.67% | 0.47% |
#34
22
Prev: #56
|
3.3 |
—
|
293,936 | 54.3% |
P
S
|
835,502 | $204,931,901 | 2025 Q2 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
AMZN
AMAZON COM INC
|
Consumer Cyclical | 0.67% | 1.99% |
#35
25
Prev: #10
|
0.3 |
—
|
-1,419,848 | -62.3% |
P
S
|
859,806 | $204,926,241 | 2009 Q3 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
GRMN
GARMIN LTD
|
Technology | 0.67% | 0.37% |
#36
50
Prev: #86
|
3.3 |
—
|
484,695 | 128.8% |
P
S
|
861,057 | $204,535,458 | 2011 Q3 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
RRX
REGAL REXNORD C...
|
Industrials | 0.67% | 0.54% |
#37
12
Prev: #49
|
2.8 |
—
|
175,259 | 25.7% |
P
S
|
856,976 | $204,123,113 | 2023 Q4 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
NTRA
NATERA INC
|
Healthcare | 0.64% | 0.63% |
#38
3
Prev: #35
|
0.8 |
—
|
-28,101 | -3.7% |
P
S
|
726,628 | $197,243,187 | 2024 Q4 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
MS
MORGAN STANLEY
|
Financial Services | 0.64% | 0.34% |
#39
54
Prev: #93
|
3.3 |
—
|
444,002 | 89.4% |
P
S
|
940,560 | $196,614,709 | 2003 Q3 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
CRS
CARPENTER TECHN...
|
Industrials | 0.63% | — |
#40
Prev: #—
|
3.8 |
—
|
314,082 | — |
NEW
|
314,082 | $193,738,341 | 2026 Q2 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
IOT
SAMSARA INC
|
Technology | 0.62% | 0.67% |
#41
11
Prev: #30
|
2.2 |
—
|
763,638 | 15.1% |
P
S
|
5,836,459 | $189,276,373 | 2021 Q4 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
DT
DYNATRACE INC
|
Technology | 0.61% | 0.65% |
#42
9
Prev: #33
|
0.7 |
—
|
39,635 | 0.9% |
P
S
|
4,249,229 | $186,583,645 | 2022 Q4 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
CAT
CATERPILLAR INC
|
Industrials | 0.61% | 0.10% |
#43
128
Prev: #171
|
3.2 |
—
|
142,295 | 440.2% |
P
S
|
174,620 | $185,952,922 | 2005 Q2 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
SMTC
SEMTECH CORP
|
Technology | 0.60% | 0.41% |
#44
30
Prev: #74
|
0.7 |
—
|
-147,326 | -11.5% |
P
S
|
1,133,268 | $183,419,455 | 2002 Q4 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
AME
AMETEK INC
|
Industrials | 0.57% | 0.67% |
#45
14
Prev: #31
|
0.7 |
—
|
-22,034 | -3.0% |
P
S
|
723,798 | $175,115,699 | 2003 Q4 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
ABVX
ABIVAX SA
|
Healthcare | 0.57% | 0.62% |
#46
9
Prev: #37
|
0.7 |
—
|
-13,113 | -1.0% |
P
S
|
1,309,825 | $174,547,280 | 2025 Q4 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
INSM
INSMED INC
|
Healthcare | 0.57% | 1.01% |
#47
29
Prev: #18
|
2.2 |
—
|
161,102 | 11.0% |
P
S
|
1,629,561 | $173,743,795 | 2020 Q2 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
ITT
ITT INC
|
Industrials | 0.54% | 0.56% |
#48
4
Prev: #44
|
2.2 |
—
|
127,073 | 18.1% |
P
S
|
830,382 | $164,216,344 | 2005 Q4 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
GILD
GILEAD SCIENCES...
|
Healthcare | 0.53% | 0.02% |
#49
163
Prev: #212
|
3.2 |
—
|
1,260,939 | 4724.4% |
P
S
|
1,287,629 | $162,679,071 | 2002 Q4 | 13F Filing | 2026-06-30 | 2026-08-12 | |||
|
PTCT
PTC THERAPEUTIC...
|
Healthcare | 0.52% | — |
#50
Prev: #—
|
3.7 |
—
|
1,956,156 | — |
NEW
|
1,956,156 | $159,563,645 | 2014 Q1 | 13F Filing | 2026-06-30 | 2026-08-12 |
Showing 1-50 of 319 holdings