Westfield Capital Management Company, L.P.

Registered investment adviser · Boston, MA · CRD #146990

Form ADV data as of 2026-09-01

Regulatory assets

$29.81 billion

Total accounts

9,391

Employees

Disclosure events

Firm details

Website: http://www.westfieldcapital.com/
Telephone: (617) 428-7100
SEC file number: 801-69413
Most recent Form ADV filing: 2026-07-01
SEC record: View this firm on the SEC's IAPD site

Disciplinary disclosures

This firm answered No to every Item 11 disciplinary question on its most recent Form ADV filing.

Assets and accounts

Provides continuous and regular supervisory or management services	Yes
Discretionary regulatory assets under management	$29.81 billion
Non-discretionary regulatory assets under management	$0
Total regulatory assets under management	$29.81 billion
Discretionary accounts	9,391
Non-discretionary accounts	0
Total accounts	9,391
Regulatory assets under management attributable to non-U.S. persons	$2.03 billion

People

Total employees (excluding clerical)	63
Employees performing investment advisory functions (including research)	19
Employees who are registered representatives of a broker-dealer	0
Employees registered as investment adviser representatives with a state	1
Employees registered as IARs for another investment adviser	0
Employees who are licensed insurance agents	0
Firms or persons who solicit advisory clients on the firm's behalf	0

Custody

Has custody of client cash or bank accounts	Yes
Has custody of client securities	Yes
Client funds and securities held in the firm's custody	$71.3 million
Clients for whom the firm has custody	2
A related person has custody of client cash or bank accounts	Yes
A related person has custody of client securities	Yes
Client funds and securities held in a related person's custody	$71.3 million
Clients for whom a related person has custody	2
The firm acts as a qualified custodian	No
A related person acts as a qualified custodian	No
Number of persons acting as qualified custodians for the firm's clients	2

How the firm is compensated

A percentage of assets under managementPerformance-based fees

Advisory services offered

Portfolio management for individuals and/or small businessesPortfolio management for investment companiesPortfolio management for pooled investment vehiclesPortfolio management for businesses or institutional clients

Affiliated related persons

Sponsor or syndicator of limited partnershipsSponsor, general partner, or managing member of pooled investment vehicles

Reported conflicts of interest

Form ADV Items 8 asks advisers to disclose arrangements that may create a conflict with client interests. This firm answered Yes to:

Buys or sells for itself securities it also recommends to clients
Recommends securities in which it has another proprietary interest
Recommends brokers or dealers to clients
Receives soft dollar benefits
Compensates a non-employee for client referrals
Provides employee compensation specifically for obtaining clients

Client types

Type of client	Clients	Assets
Individuals (other than high net worth individuals)	8,398	$698.8 million
High net worth individuals	512	$1.34 billion
Investment companies	15	$10.00 billion
Pooled investment vehicles (other than investment companies and BDCs)	15	$4.52 billion
Pension and profit sharing plans (not the participants or government plans)	177	$6.37 billion
Charitable organizations	138	$1.44 billion
State or municipal government entities (including government pension plans)	38	$4.29 billion
Other investment advisers	1	$661.0 million
Corporations or other businesses not listed above	97	$496.4 million