Filed: 5/11/2026ACC: 0001177719-26-000018
📋 What this filing means
WESTFIELD CAPITAL MANAGEMENT CO LP filed this quarterly 13F‑HR report disclosing 250 equity positions with a total reported market value of $23.83B. This filing provides a transparent view of the manager's long equity holdings as of the quarter end.
250
Positions
$23.83B
Total AUM (reported)
217.59M
Total Shares
Allocation by class
COM$15.22B63.9%
COM CL A$1.43B6.0%
CL A$1.19B5.0%
SPONSORED ADR$1.12B4.7%
SHS$946.46M4.0%
COM NEW$942.65M4.0%
CAP STK CL A$582.81M2.4%
Portfolio Concentration
Top 3$3.06B12.8%
4–10$4.17B17.5%
11–25$3.85B16.1%
Rest$12.76B53.5%
Top 3 weight
12.8%
Top 10 weight
30.3%
Voting Authority Distribution
Total shares with voting rights: 217.59M
Sole
Full voting authority
189.27M
shares
% of voting shares87.0%
Shared
Joint voting authority
0.00
shares
% of voting shares0.0%
None
No voting authority
28.32M
shares
% of voting shares13.0%
Investment Discretion (by position count)
Sole250
Shared0
Other0
Dominant voting typeSole · 87.0% of voting shares
Institutional Holdings250
Rows:
NVIDIA CORPORATION
SOLEShares6.32M
TypeSH
Market value$1.10B
4.62%
Sole
4.67M
Shared
0.00
None
1.65M
ASCENDIS PHARMA A/S
SOLEShares4.81M
TypeSH
Market value$1.10B
4.62%
Sole
4.03M
Shared
0.00
None
780.71K
COMFORT SYS USA INC
SOLEShares620.91K
TypeSH
Market value$856.24M
3.59%
Sole
518.49K
Shared
0.00
None
102.42K
APPLE INC
SOLEShares3.13M
TypeSH
Market value$795.15M
3.34%
Sole
2.36M
Shared
0.00
None
773.18K
FTAI AVIATION LTD
SOLEShares2.85M
TypeSH
Market value$697.82M
2.93%
Sole
2.40M
Shared
0.00
None
444.51K
MICROSOFT CORP
SOLEShares1.65M
TypeSH
Market value$610.60M
2.56%
Sole
1.21M
Shared
0.00
None
435.73K
ALPHABET INC
SOLEShares2.03M
TypeSH
Market value$582.81M
2.45%
Sole
1.46M
Shared
0.00
None
568.05K
HOWMET AEROSPACE INC
SOLEShares2.29M
TypeSH
Market value$527.68M
2.21%
Sole
1.66M
Shared
0.00
None
629.86K
VERTIV HOLDINGS CO
SOLEShares1.92M
TypeSH
Market value$481.54M
2.02%
Sole
1.52M
Shared
0.00
None
405.32K
AMAZON COM INC
SOLEShares2.28M
TypeSH
Market value$474.78M
1.99%
Sole
1.69M
Shared
0.00
None
589.85K
AXON ENTERPRISE INC
SOLEShares1.06M
TypeSH
Market value$451.93M
1.90%
Sole
814.53K
Shared
0.00
None
249.60K
BROADCOM INC
SOLEShares1.24M
TypeSH
Market value$382.84M
1.61%
Sole
909.21K
Shared
0.00
None
327.71K
ELI LILLY & CO
SOLEShares364.58K
TypeSH
Market value$335.33M
1.41%
Sole
272.42K
Shared
0.00
None
92.16K
TAPESTRY INC
SOLEShares2.20M
TypeSH
Market value$310.28M
1.30%
Sole
1.88M
Shared
0.00
None
319.40K
META PLATFORMS INC
SOLEShares526.82K
TypeSH
Market value$301.41M
1.26%
Sole
386.66K
Shared
0.00
None
140.16K
LPL FINL HLDGS INC
SOLEShares881.51K
TypeSH
Market value$265.18M
1.11%
Sole
699.93K
Shared
0.00
None
181.57K
MKS INC.
SOLEShares1.05M
TypeSH
Market value$240.56M
1.01%
Sole
907.62K
Shared
0.00
None
139.14K
INSMED INC
SOLEShares1.47M
TypeSH
Market value$240.12M
1.01%
Sole
1.26M
Shared
0.00
None
205.17K
VAXCYTE INC
SOLEShares3.65M
TypeSH
Market value$211.88M
0.89%
Sole
3.36M
Shared
0.00
None
286.79K
ROCKET LAB CORP
SOLEShares3.17M
TypeSH
Market value$203.75M
0.85%
Sole
2.56M
Shared
0.00
None
617.42K
NETFLIX INC.
SOLEShares1.97M
TypeSH
Market value$189.41M
0.79%
Sole
1.30M
Shared
0.00
None
665.48K
API GROUP CORP
SOLEShares4.63M
TypeSH
Market value$187.81M
0.79%
Sole
3.80M
Shared
0.00
None
833.89K
QUANTA SVCS INC
SOLEShares331.82K
TypeSH
Market value$182.17M
0.76%
Sole
224.94K
Shared
0.00
None
106.87K
GE VERNOVA INC
SOLEShares199.31K
TypeSH
Market value$173.97M
0.73%
Sole
120.33K
Shared
0.00
None
78.98K
ARES MANAGEMENT CORPORATION
SOLEShares1.57M
TypeSH
Market value$171.59M
0.72%
Sole
1.17M
Shared
0.00
None
404.58K
| Issuer | Class | Shares | Type | Value / Portfolio % | Voting — Sole | Shared | None |
|---|---|---|---|---|---|---|---|
NVIDIA CORPORATIONSOLE | COM | 6.32M | SH | $1.10B 4.62% | 4.67M | 0.00 | 1.65M |
ASCENDIS PHARMA A/SSOLE | SPONSORED ADR | 4.81M | SH | $1.10B 4.62% | 4.03M | 0.00 | 780.71K |
COMFORT SYS USA INCSOLE | COM | 620.91K | SH | $856.24M 3.59% | 518.49K | 0.00 | 102.42K |
APPLE INCSOLE | COM | 3.13M | SH | $795.15M 3.34% | 2.36M | 0.00 | 773.18K |
FTAI AVIATION LTDSOLE | SHS | 2.85M | SH | $697.82M 2.93% | 2.40M | 0.00 | 444.51K |
MICROSOFT CORPSOLE | COM | 1.65M | SH | $610.60M 2.56% | 1.21M | 0.00 | 435.73K |
ALPHABET INCSOLE | CAP STK CL A | 2.03M | SH | $582.81M 2.45% | 1.46M | 0.00 | 568.05K |
HOWMET AEROSPACE INCSOLE | COM | 2.29M | SH | $527.68M 2.21% | 1.66M | 0.00 | 629.86K |
VERTIV HOLDINGS COSOLE | COM CL A | 1.92M | SH | $481.54M 2.02% | 1.52M | 0.00 | 405.32K |
AMAZON COM INCSOLE | COM | 2.28M | SH | $474.78M 1.99% | 1.69M | 0.00 | 589.85K |
AXON ENTERPRISE INCSOLE | COM | 1.06M | SH | $451.93M 1.90% | 814.53K | 0.00 | 249.60K |
BROADCOM INCSOLE | COM | 1.24M | SH | $382.84M 1.61% | 909.21K | 0.00 | 327.71K |
ELI LILLY & COSOLE | COM | 364.58K | SH | $335.33M 1.41% | 272.42K | 0.00 | 92.16K |
TAPESTRY INCSOLE | COM | 2.20M | SH | $310.28M 1.30% | 1.88M | 0.00 | 319.40K |
META PLATFORMS INCSOLE | CL A | 526.82K | SH | $301.41M 1.26% | 386.66K | 0.00 | 140.16K |
LPL FINL HLDGS INCSOLE | COM | 881.51K | SH | $265.18M 1.11% | 699.93K | 0.00 | 181.57K |
MKS INC.SOLE | COM | 1.05M | SH | $240.56M 1.01% | 907.62K | 0.00 | 139.14K |
INSMED INCSOLE | COM PAR $.01 | 1.47M | SH | $240.12M 1.01% | 1.26M | 0.00 | 205.17K |
VAXCYTE INCSOLE | COM | 3.65M | SH | $211.88M 0.89% | 3.36M | 0.00 | 286.79K |
ROCKET LAB CORPSOLE | COM | 3.17M | SH | $203.75M 0.85% | 2.56M | 0.00 | 617.42K |
NETFLIX INC.SOLE | COM | 1.97M | SH | $189.41M 0.79% | 1.30M | 0.00 | 665.48K |
API GROUP CORPSOLE | COM STK | 4.63M | SH | $187.81M 0.79% | 3.80M | 0.00 | 833.89K |
QUANTA SVCS INCSOLE | COM | 331.82K | SH | $182.17M 0.76% | 224.94K | 0.00 | 106.87K |
GE VERNOVA INCSOLE | COM | 199.31K | SH | $173.97M 0.73% | 120.33K | 0.00 | 78.98K |
ARES MANAGEMENT CORPORATIONSOLE | CL A COM STK | 1.57M | SH | $171.59M 0.72% | 1.17M | 0.00 | 404.58K |
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