WESTFIELD CAPITAL MANAGEMENT CO LP
Q1 2025 Form 13-F

BOSTON, MASSACHUSETTS
CIK 0001177719 · CRD 146990 · SEC-registered investment adviser
$20.5B Reported Value Total

WESTFIELD CAPITAL MANAGEMENT COMPANY, L.P. reports 975 total accounts under management (AUM). There are 975 discretionary accounts valued at $23,551,448,142, and 0 non-discretionary accounts.

Source: Form ADV filed * Note that certain holdings are exempt from Form 13-F reporting, so the AUM totals may be greater than the Form 13-F total.
SEC Registered Discretionary Manager
Firm Brochure (Part 2A) Client Relationship Summary (Form CRS)
Private funds (Form ADV)
11 funds · $185.4M gross asset value
Other: $68.8M · Hedge Fund: $34.8M · Private Equity Fund: $128.8K
Source: Form ADV filed 2026-07-01
Reported value
$20.5B
Quarter over quarter
-9.5%
Holdings
244
Top-10 concentration
29.4%

Filing Structure

Reports holdings for

Holdings reported by

Key People

Form ADV owners & control persons
William Albert Muggia
MEMBER OF MANAGEMENT COMMITTEE
Kathryn Ann Kearney
PARTNER, CHIEF FINANCIAL OFFICER AND CHIEF COMPLIANCE OFFICER
Richard Dailyong Lee
CHIEF INVESTMENT OFFICER
Q4 2024
Q2 2025
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Coverage begins with the second quarter of 2013. Earlier quarters are not shown while their accuracy is being verified.

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Q1 2025 13F filing summary

Period of report March 31, 2025
Filed May 09, 2025
Form 13F-HR
Reported value $20.5B
Positions 244
Change in reported value -10.5%
New positions 46
Exited positions 41
Position turnover 30.5%
Top-10 concentration 29.4%

13F filings by quarter

Quarter Positions Value
Q2 2026 13F
Filed Aug 12, 2026
 278 $30.6B
Q1 2026 13F
Filed May 11, 2026
 250 $23.8B
Q4 2025 13F
Filed Feb 11, 2026
 241 $24.0B
Q3 2025 13F
Filed Nov 12, 2025
 235 $23.8B
Q2 2025 13F
Filed Aug 12, 2025
 239 $23.8B
Q1 2025 13F
Filed May 9, 2025
 244 $20.5B
Q4 2024 13F
Filed Feb 11, 2025
 239 $23.0B
Q3 2024 13F
Filed Nov 12, 2024
 247 $22.1B
Q2 2024 13F
Filed Aug 14, 2024
 248 $20.4B
Q1 2024 13F
Filed May 10, 2024
 244 $19.0B
Q4 2023 13F
Filed Feb 9, 2024
 239 $17.2B
Q3 2023 13F
Filed Nov 13, 2023
 234 $14.7B
Q2 2023 13F
Filed Aug 11, 2023
 227 $15.7B
Q1 2023 13F
Filed May 12, 2023
 222 $14.2B
Q4 2022 13F
Filed Feb 13, 2023
 226 $13.0B
Q3 2022 13F
Filed Nov 14, 2022
 230 $12.6B
Q2 2022 13F
Filed Aug 12, 2022
 235 $12.7B
Q1 2022 13F
Filed May 16, 2022
 235 $15.6B
Q4 2021 13F
Filed Feb 10, 2022
 244 $16.8B
Q3 2021 13F
Filed Nov 12, 2021
 235 $16.6B

33 earlier quarters on file — choose one from the quarter menu above.

Top 20 holdings · Q1 2025

# Holding Reported value % of portfolio
1 ASND ASCENDIS PHARMA A/S $854.0M 4.16%
2 NVDA NVIDIA CORPORATION $795.1M 3.87%
3 AAPL APPLE INC $755.5M 3.68%
4 MSFT MICROSOFT CORP $687.9M 3.35%
5 AMZN AMAZON COM INC $658.8M 3.21%
6 GOOGL ALPHABET INC $535.0M 2.6%
7 META META PLATFORMS INC $517.9M 2.52%
8 AXON AXON ENTERPRISE INC $488.0M 2.37%
9 TDG TRANSDIGM GROUP INC $437.3M 2.13%
10 V VISA INC $317.0M 1.54%
11 FIX COMFORT SYS USA INC $286.8M 1.4%
12 LPLA LPL FINL HLDGS INC $271.6M 1.32%
13 NOW SERVICENOW INC $255.0M 1.24%
14 TPR TAPESTRY INC $253.6M 1.23%
15 LEGN LEGEND BIOTECH CORP $234.7M 1.14%
16 AVGO BROADCOM INC $234.1M 1.14%
17 LLY ELI LILLY & CO $213.9M 1.04%
18 FTAI FTAI AVIATION LTD $210.1M 1.02%
19 CRM SALESFORCE INC $210.1M 1.02%
20 PGR PROGRESSIVE CORP $201.6M 0.98%

Values as reported on the Q1 2025 Form 13F. Every position is in the holdings table below.

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