WESTFIELD CAPITAL MANAGEMENT CO LP

Overview

• HeadquartersBoston, United States²
• Legal formLimited Partnership²
• Kind of organizationLimited partnership²
• LEI549300S6UXVEE0EKUL97²
• StatusActive²
• LEI statusLapsed (not renewed)²
• Registered addressC/O Corporation Service Company, 19808 Wilmington, United States²
• Registered withDivision of Corporations, Department of State, 4519363²

See how the biggest companies compare on our leaderboards

Corporate structure

WESTFIELD CAPITAL MANAGEMENT CO LP is part of a group headed by Wms Management LLC. 10 entities, 3 countries on record. Switch between the flow chart and the network, and select any entity to see its details.

Built from parent and subsidiary links from GLEIF, the Global Legal Entity Identifier Foundation (CC0); major holders from Schedules 13D and 13G; stakes of 5% or more it reported on Schedules 13D and 13G (7 companies); owners and owned firms from Form ADV, the registration investment advisers file with the SEC. Each entity in the chart links to its source.

Investment adviser

WESTFIELD CAPITAL MANAGEMENT CO LP is registered with the SEC as an investment adviser. This is what it reports on Form ADV, the registration every adviser files and keeps current.

• Assets it manages$29.8B³ 9,391 accounts, all with discretion
• Employees63 19 in investment advice or research
• ClientsInvestment companies: 15 ($10.0B); Pension and profit sharing plans (but not the plan participants or: 177 ($6.4B); Pooled investment vehicles (other than investment companies and: 15 ($4.5B); State or municipal government entities (including government pension: 38 ($4.3B); Charitable organizations: 138 ($1.4B); High net worth individuals: 512 ($1.3B); Individuals (other than high net worth individuals): 8,398 ($698.8M); Other investment advisers: 1 ($661.0M); Corporations or other businesses not listed above: 97 ($496.4M)
• How it is paidA percentage of assets under its management; Performance-based fees
• What it doesPortfolio management for individuals and/or small businesses; Portfolio management for investment companies; Portfolio management for pooled investment vehicles (other than investment companies); Portfolio management for businesses (other than small businesses) or institutional clients (other than registered investment companies and other pooled investment vehicles)
• Holds client assetsYes: cash and securities
• RegistrationSEC 801-69413, CRD 146990 IAPD record

Who owns it

Owners of 5% or more as the firm lists them (Schedule A), and the owners of those owners up the chain (Schedule B).

• WMS MANAGEMENT LLCowns 75% or more, since 06/2008
• MG AM HOLDING, INC.owns 10% to 25%, since 04/2025
• Robert Tizoc Floresowns general partner, trustee or manager of WMS MANAGEMENT MANAGEMENT LLC COMMITTEE, since 01/2013
• Kathryn Ann Kearneyowns general partner, trustee or manager of WMS MANAGEMENT MANAGEMENT LLC COMMITTEE, since 01/2021
• Richard Dailyong Leeowns general partner, trustee or manager of WMS MANAGEMENT MANAGEMENT LLC COMMITTEE, since 01/2013
• MONEX GROUP, INC.owns general partner, trustee or manager of MG AM HOLDING, INC. MG AM HOLDING,, since 04/2025
• John Morgen Montgomeryowns general partner, trustee or manager of WMS MANAGEMENT MANAGEMENT LLC COMMITTEE, since 01/2013
• Justin Matthew Moscardelliowns general partner, trustee or manager of WMS MANAGEMENT MANAGEMENT LLC COMMITTEE, since 01/2024
• Jenny Ann Mullerowns general partner, trustee or manager of WMS MANAGEMENT MANAGEMENT LLC COMMITTEE, since 01/2021
• Matthew Robert Rennaowns general partner, trustee or manager of WMS MANAGEMENT MANAGEMENT LLC COMMITTEE, since 01/2021
• WMS MANAGEMENT LLCowns 75% or more of WMS GENERAL PARTNER LLC, since 06/2008
• William Albert Muggiaowns 50% to 75% of WMS MANAGEMENT MANAGEMENT LLC COMMITTEE, since 06/2008

Filings

23 filings to the SEC since October 2021: 23 other. The latest 20:

1. Aug 12, 202613F-HR EDGAR
2. Jul 31, 2026N-PX EDGAR
3. May 11, 202613F-HR EDGAR
4. Feb 11, 202613F-HR EDGAR
5. Nov 12, 202513F-HR EDGAR
6. Aug 12, 202513F-HR EDGAR
7. Aug 6, 2025N-PX EDGAR
8. May 9, 202513F-HR EDGAR
9. Feb 11, 202513F-HR EDGAR
10. Nov 12, 202413F-HR EDGAR
11. Aug 16, 2024N-PX EDGAR
12. Aug 14, 202413F-HR EDGAR
13. May 10, 202413F-HR EDGAR
14. Feb 9, 202413F-HR EDGAR
15. Nov 13, 202313F-HR EDGAR
16. Aug 11, 202313F-HR EDGAR
17. May 12, 202313F-HR EDGAR
18. Feb 13, 202313F-HR EDGAR
19. Nov 14, 202213F-HR EDGAR
20. Aug 12, 202213F-HR EDGAR

Every filing from the last five years, summarized. The full record is on SEC EDGAR.

Stakes it holds

WESTFIELD CAPITAL MANAGEMENT CO LP has told the SEC it owns more than 5% of 7 companies, latest first (Schedules 13D and 13G).

• IMAX CorporationSCHEDULE 13G/A May 5, 2026 to Jun 3, 2026⁴
• Bicycle Therapeutics (United Kingdom)SCHEDULE 13G/A Feb 11, 2025 to Mar 4, 2026⁵
• Ascendis Pharma A/SSCHEDULE 13G/A Feb 2, 2023 to Feb 11, 2026⁶
• FlywireSCHEDULE 13G/A Feb 11, 2025 to Mar 5, 2025⁷
• Innoviva, Inc.SCHEDULE 13G/A Feb 1, 2022 to Feb 11, 2025⁸
• Mural Oncology plcSC 13G/A Jan 10, 2024 to Aug 5, 2024⁹
• Ironwood PharmaceuticalsSC 13G/A Feb 1, 2022 to Jul 5, 2023¹⁰