Westfield Capital Management Company, L.P.
SEC-registered
Investment Adviser · Large ($10B–$100B)
CRD 146990
· SEC file 801-69413
· Boston, MA
· WWW.WESTFIELDCAPITAL.COM
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ADV data as of Jul 01, 2026
- Regulatory AUM
- $29.8B
- Discretionary
- $29.8B
- Clients
- 9,391
- Avg AUM / client
- $3.2M
- Accounts
- 9,391
- Employees
- 63
AUM over time
$11.8B
$29.8B
Dec 2011
Jul 2026
Annual snapshots from Form ADV filings · as of Jul 01, 2026
Asset allocation (SMA assets by investment type)
as of Jul 01, 2026
Exchange-traded equities
$29.2B
98%
Cash & equivalents
$596M
2%
Share of SMA assets by investment vehicle type, as filed in Form ADV Item 5.K. Dollar figures are percentages applied to total regulatory AUM.
Who they serve
| Client type | Clients | AUM | % of AUM |
|---|---|---|---|
| Individuals (non-high net worth) | 8,398 | $699M | 2.34% |
| High net worth individuals | 512 | $1.3B | 4.49% |
| Investment companies | 15 | $10.0B | 33.5% |
| Pooled investment vehicles (non-investment companies) | 15 | $4.5B | 15.2% |
| Pension and profit sharing plans | 177 | $6.4B | 21.4% |
| Charitable organizations | 138 | $1.4B | 4.82% |
| State or municipal government entities | 38 | $4.3B | 14.4% |
| Other investment advisers | 1 | $661M | 2.22% |
| Corporations and other businesses | 97 | $496M | 1.67% |
Private funds (3)
Reported in Form ADV Section 7.B.(1), filing of Sep 2024 · $57.3M combined gross assets
| Fund | Type | Domicile | Gross assets | Owners |
|---|---|---|---|---|
| Westfield Absolute Return Fund Limited Partnership | Hedge Fund | Delaware | $32.5M | 20 |
| Westfield Select Growth Equity Lp | Other Private Fund | Delaware | $22.8M | 8 |
| Westfield Disruptive Innovation Fund Lp | Other Private Fund | Delaware | $2.1M | 4 |
Retirement plan clients
Plans that reported this firm as an investment service provider on Form 5500 Schedule C.
| Plan | Location | Plan year |
|---|---|---|
| Standex International Corporation Pension Plans Standex International Corporation | 2024 | |
| United Food & Commercial Workers Union Local 152 Retail Meat Pension Plan Board Of Trustees, United Food & Commercial Workers Union Local 152 | 2024 | |
| Pipe Trades Services Mn Pension Fund Trustees Of The Pipe Trades Services Mn Pension Trust | 2024 | |
| Morgan Stanley 401(k) Plan Morgan Stanley Domestic Holdings, Llc | 2024 | |
| Bakery & Confectionery Union & Industry International Pension Fund Joint Board Of Trustees, Bakery & Confectionery Union & Industry | 2024 | |
| Sheet Metal Workers' National Pension Fund Bd Of Trustees Sheet Metal Workers' National Pension Fund | 2024 | |
| The Albany Medical Center Retirement Plan Albany Med Health System | 2024 | |
| Heat & Frost Insulators And Allied Workers Local 6 Pension Fund Bd Of Trustees Heat & Frost Insulators And Allied Workers Local 6 Pen | 2024 | |
| Southern California Local 831 Employer Pension Fund Board Of Trustees, Southern California Local 831 | 2024 | |
| Ironworkers Local #16 Pension Plan Board Of Trustees, Ironworkers Local #16 Pension Plan | 2024 | |
| Ufcw Union & Partcipating Food Industry Employers Tri State Pension Fund Ufcw Union & Participating Food Industry Employers Tri State Pension F | 2024 | |
| I. A. T. S. E. National Pension Fund Board Of Trustees I.A.T.S.E. National Pension Fund | 2024 | |
| Retirement Income Plan For Employees Of The Chamber Of Commerce Of The United States Of America Chamber Of Commerce Of The United States Of America | 2024 | |
| Sheet Metal Workers Local Union No. 28 Pension Fund Board Of Trustees Of Smw Lu No. 28 Pension Fund | 2024 | |
| Lear Corporation Pension Plan Lear Corporation | 2024 | |
| Lear Combined Pension Plan Lear Corporation | 2024 | |
| Smart Local Unions And Councils Pension Fund Board Of Trustees Of The Smart Local Unions And Councils Pension Fund | 2024 | |
| Operating Engineers Local 101 Pension Fund Board Of Trustees Of Operating Engineers Local 101 Pension Fund | 2024 | |
| Teamsters Employers Local 945 Pension Fund Board Of Trustees Teamsters Local 945 Pension Fund | 2024 | |
| Teamsters Local 469 Pension Plan Trustees Of Teamsters Local No. 469 Pension Fund | 2024 | |
| Central Pennsylvania Teamsters Defined Benefit Plan Central Pennsylvania Teamsters Pension Fund, Trustees | 2024 | |
| Truist Financial Corporation Pension Plan Truist Financial Corporation | 2024 | |
| Ufcw Unions And Participating Employers Pension Plan Board Of Trustees The Ufcw Unions And Participating Employers Pension | 2024 | |
| Ameren Retirement Plan Ameren Corporation | St. Louis, MO | 2024 |
| Genuine Parts Company Pension Plan Genuine Parts Company | 2024 |
People (9)
roster as of Jul 20, 2026| Name | Role / title | Credentials | With firm since | Ownership |
|---|---|---|---|---|
| William Albert Muggia | Chief Executive Officer And Chief Investment Officer | Nov 2001 (25y) | ≈ 37.5% – 75% via Wms Management Llc | |
| Kearney, Kathryn, Ann | Partner, Chief Financial Officer And Chief Compliance Officer | Dec 2012 (14y) | Less than 5% | |
| Flores, Robert, Tizoc | Member Of Management Committee | Jan 2013 (14y) | GP / trustee / elected manager of Wms Management Llc (indirect) | |
| Lee, Richard, Dailyong | Member Of Management Committee | Jan 2013 (14y) | Less than 5% | |
| Meyers, Ethan, Joseph | Member Of Management Committee | Jan 2013 (14y) | GP / trustee / elected manager of Wms Management Llc (indirect) | |
| Montgomery, John, Morgen | Member Of Management Committee | Jan 2013 (14y) | Less than 5% | |
| Muller, Jenny, Ann | Member Of Management Committee | Jan 2021 (6y) | GP / trustee / elected manager of Wms Management Llc (indirect) | |
| Renna, Matthew, Robert | Member Of Management Committee | Jan 2021 (6y) | GP / trustee / elected manager of Wms Management Llc (indirect) | |
| Moscardelli, Justin, Matthew | Member Of Management Committee | Jan 2024 (3y) | GP / trustee / elected manager of Wms Management Llc (indirect) |
Entity owners (Schedule A/B)
| Entity | Title / status | Since | Sch. | Ownership |
|---|---|---|---|---|
| Wms Management Llc | Limited Partner | Jun 2008 | A | 75% or more |
| Wms General Partner Llc | General Partner | Jun 2008 | A | Less than 5% |
| Wms Management Llc | Sole Member | Jun 2008 | B | ≈ 0% – 5% via Wms General Partner Llc |
Undisclosed: 0% – 25% of the firm is not attributable from the filed Schedule A bands.
Estimated effective ownership (look-through of filed bands):
- William Albert Muggia: 50% – 75% of Wms Management Llc × 75% – 100% direct ≈ 37.5% – 75% of the firm
- Wms Management Llc: 75% – 100% of Wms General Partner Llc × 0% – 5% direct ≈ 0% – 5% of the firm
Roster from the IAPD representatives feed; ownership and acquisition dates from Form ADV Schedule A/B. "Since" is the earliest filed registration or acquisition date.
Private funds (3, $57.3M gross assets)
| Fund | Type | Gross assets | Min. investment | Owners |
|---|---|---|---|---|
| Westfield Absolute Return Fund Limited Partnership | Hedge Fund | $32.5M | $500K | 20 |
| Westfield Select Growth Equity Lp | Other Private Fund | $22.8M | $1.0M | 8 |
| Westfield Disruptive Innovation Fund Lp | Other Private Fund | $2.1M | $1.0M | 4 |
From Form ADV Section 7.B private fund reporting.
Retirement plans served (25)
| Plan | Sponsor | Participants | Plan assets | As of |
|---|---|---|---|---|
| Standex International Corporation Pension Plans | Standex International Corporation | 91 | $150M | 07/01/2024 |
| United Food & Commercial Workers Union Local 152 Retail Meat Pension Plan | Board Of Trustees, United Food & Commercial Workers Union Local 152 | 1,488 | $530M | 07/01/2024 |
| Pipe Trades Services Mn Pension Fund | Trustees Of The Pipe Trades Services Mn Pension Trust | 4,758 | $1.6B | 05/01/2024 |
| Morgan Stanley 401(k) Plan | Morgan Stanley Domestic Holdings, Llc | 54,084 | $22.2B | 01/01/2024 |
| Bakery & Confectionery Union & Industry International Pension Fund | Joint Board Of Trustees, Bakery & Confectionery Union & Industry | 14,943 | $6.6B | 01/01/2024 |
| Sheet Metal Workers' National Pension Fund | Bd Of Trustees Sheet Metal Workers' National Pension Fund | 66,166 | $8.9B | 01/01/2024 |
| The Albany Medical Center Retirement Plan | Albany Med Health System | 7,970 | $290M | 01/01/2024 |
| Heat & Frost Insulators And Allied Workers Local 6 Pension Fund | Bd Of Trustees Heat & Frost Insulators And Allied Workers Local 6 Pen | 597 | $166M | 01/01/2024 |
| Southern California Local 831 Employer Pension Fund | Board Of Trustees, Southern California Local 831 | 1,227 | $489M | 01/01/2024 |
| Ironworkers Local #16 Pension Plan | Board Of Trustees, Ironworkers Local #16 Pension Plan | 112 | $127M | 01/01/2024 |
| Ufcw Union & Partcipating Food Industry Employers Tri State Pension Fund | Ufcw Union & Participating Food Industry Employers Tri State Pension F | 6,739 | $872M | 01/01/2024 |
| I. A. T. S. E. National Pension Fund | Board Of Trustees I.A.T.S.E. National Pension Fund | 15,401 | $673M | 01/01/2024 |
| Retirement Income Plan For Employees Of The Chamber Of Commerce Of The United States Of America | Chamber Of Commerce Of The United States Of America | 41 | $133M | 01/01/2024 |
| Sheet Metal Workers Local Union No. 28 Pension Fund | Board Of Trustees Of Smw Lu No. 28 Pension Fund | 1,989 | $364M | 01/01/2024 |
| Lear Corporation Pension Plan | Lear Corporation | 495 | $189M | 01/01/2024 |
| Lear Combined Pension Plan | Lear Corporation | 570 | $118M | 01/01/2024 |
| Smart Local Unions And Councils Pension Fund | Board Of Trustees Of The Smart Local Unions And Councils Pension Fund | 995 | $397M | 01/01/2024 |
| Operating Engineers Local 101 Pension Fund | Board Of Trustees Of Operating Engineers Local 101 Pension Fund | 3,625 | $1.0B | 01/01/2024 |
| Teamsters Employers Local 945 Pension Fund | Board Of Trustees Teamsters Local 945 Pension Fund | 385 | $100M | 01/01/2024 |
| Teamsters Local 469 Pension Plan | Trustees Of Teamsters Local No. 469 Pension Fund | 69 | $164M | 01/01/2024 |
| Central Pennsylvania Teamsters Defined Benefit Plan | Central Pennsylvania Teamsters Pension Fund, Trustees | 5,287 | $1.5B | 01/01/2024 |
| Truist Financial Corporation Pension Plan | Truist Financial Corporation | 33,167 | $14.7B | 01/01/2024 |
| Ufcw Unions And Participating Employers Pension Plan | Board Of Trustees The Ufcw Unions And Participating Employers Pension | 1,655 | $94.8M | 01/01/2024 |
| Ameren Retirement Plan | Ameren Corporation | 9,113 | $4.8B | 01/01/2024 |
| Genuine Parts Company Pension Plan | Genuine Parts Company | 3,705 | $2.0B | 01/01/2024 |
From Form 5500 service-provider disclosures.
Documents (1 archived)
| Form | Period | Size | |
|---|---|---|---|
| Form ADV (full filing) | 07/01/2026 | 1.42 MB | View · PDF · Source ↗ |
Archived copies of the firm's regulatory filings, versioned by content hash.
Disciplinary disclosures
No disciplinary events reported on the firm's latest Form ADV filing.
How they charge
- • Percentage of assets under management
- • Performance-based fees
Services
- • Portfolio management for individuals/small businesses
- • Portfolio management for investment companies
- • Portfolio management for pooled investment vehicles
- • Portfolio management for businesses/institutional clients
Custody
Reported custodians
- Northern Trust $3.7B (13% of AUM) Jul 2026
- State Street $2.7B (9% of AUM) Jul 2026
- BNY Mellon $2.6B (9% of AUM) Jul 2026
Amounts as reported in ADV Item 5.K.(3) (custodians holding 10%+ of SMA assets).
Firm reports having custody of client funds or securities (Item 9.A).
Source
All data on this page comes from this firm's Form ADV filings, reproduced without modification. Latest filing: Jul 01, 2026.
View current Form ADV (SEC/IAPD) ↗