WESTFIELD CAPITAL MANAGEMENT CO LP
All 13F Filings
- Location
- Boston, MA
- Most recent 13F
- Q4 2025
- Holdings value ($000)
- 24,005,012
- Description
- Boston Massachusetts based research oriented capital manager with a partner led organization and a mandate specific and implementation minded investment mandate. The approach emphasizes fundamental research depth, active stewardship and governance oversight, and valuation discipline and downside awareness for long horizon investment mandates. Mandate delivery is supported by disciplined controls, selective risk taking, and consistent review practices through fundamental conviction testing and portfolio discipline.
- Founded
- 1989
- Chairman
- —
- CEO
- Will Muggia
- All SEC filings
- View on sec.gov
Sector allocation over time (stocks only)
Stacked by quarter. Hover to see detailed sector breakdown for any quarter.
| Quarter | Date Filed | Holdings | Value ($000) | Form Type | Name |
|---|---|---|---|---|---|
| Q4 2025 | 2/11/2026 | 241 | 24,005,012 | 13F-HR | WESTFIELD CAPITAL MANAGEMENT CO LP |
| Q3 2025 | 11/12/2025 | 235 | 23,832,915 | 13F-HR | WESTFIELD CAPITAL MANAGEMENT CO LP |
| Q2 2025 | 8/12/2025 | 239 | 23,843,766 | 13F-HR | WESTFIELD CAPITAL MANAGEMENT CO LP |
| Q1 2025 | 5/9/2025 | 244 | 20,549,795 | 13F-HR | WESTFIELD CAPITAL MANAGEMENT CO LP |
| Q4 2024 | 2/11/2025 | 239 | 22,971,696 | 13F-HR | WESTFIELD CAPITAL MANAGEMENT CO LP |
| Q3 2024 | 11/12/2024 | 247 | 22,133,837 | 13F-HR | WESTFIELD CAPITAL MANAGEMENT CO LP |
| Q2 2024 | 8/14/2024 | 248 | 20,353,526 | 13F-HR | WESTFIELD CAPITAL MANAGEMENT CO LP |
| Q1 2024 | 5/10/2024 | 244 | 19,047,709 | 13F-HR | WESTFIELD CAPITAL MANAGEMENT CO LP |
| Q4 2023 | 2/9/2024 | 239 | 17,157,520 | 13F-HR | WESTFIELD CAPITAL MANAGEMENT CO LP |
| Q3 2023 | 11/13/2023 | 234 | 14,680,796 | 13F-HR | WESTFIELD CAPITAL MANAGEMENT CO LP |
| Q2 2023 | 8/11/2023 | 227 | 15,739,052 | 13F-HR | WESTFIELD CAPITAL MANAGEMENT CO LP |
| Q1 2023 | 5/12/2023 | 222 | 14,150,981 | 13F-HR | WESTFIELD CAPITAL MANAGEMENT CO LP |
| Q4 2022 | 2/13/2023 | 226 | 12,964,837 | 13F-HR | WESTFIELD CAPITAL MANAGEMENT CO LP |
| Q2 2022 | 8/12/2022 | 235 | 12,700,476 | 13F-HR | WESTFIELD CAPITAL MANAGEMENT CO LP |
| Q1 2022 | 5/16/2022 | 235 | 15,601,903 | 13F-HR | WESTFIELD CAPITAL MANAGEMENT CO LP |
| Q4 2021 | 2/10/2022 | 244 | 16,825,241 | 13F-HR | WESTFIELD CAPITAL MANAGEMENT CO LP |
| Q3 2021 | 11/12/2021 | 235 | 16,580,184 | 13F-HR | WESTFIELD CAPITAL MANAGEMENT CO LP |
| Q2 2021 | 8/10/2021 | 241 | 16,697,140 | 13F-HR | WESTFIELD CAPITAL MANAGEMENT CO LP |
| Q1 2021 | 5/14/2021 | 243 | 16,089,955 | 13F-HR | WESTFIELD CAPITAL MANAGEMENT CO LP |
| Q4 2020 | 2/12/2021 | 247 | 16,852,328 | 13F-HR | WESTFIELD CAPITAL MANAGEMENT CO LP |
| Q3 2020 | 11/13/2020 | 235 | 15,448,316 | 13F-HR | WESTFIELD CAPITAL MANAGEMENT CO LP |
| Q2 2020 | 8/13/2020 | 230 | 14,541,816 | 13F-HR | WESTFIELD CAPITAL MANAGEMENT CO LP |
| Q1 2020 | 5/14/2020 | 216 | 11,354,045 | 13F-HR | WESTFIELD CAPITAL MANAGEMENT CO LP |
| Q4 2019 | 2/13/2020 | 231 | 14,042,622 | 13F-HR | WESTFIELD CAPITAL MANAGEMENT CO LP |
| Q1 2014 | 5/12/2014 | 324 | 16,712,176 | 13F-HR | WESTFIELD CAPITAL MANAGEMENT CO LP |
| Q4 2013 | 2/7/2014 | 324 | 16,986,123 | 13F-HR | WESTFIELD CAPITAL MANAGEMENT CO LP |
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Money flow by instrument (QoQ, ex-options)
| Type | Value ($000) | Share % | Inflow | Outflow | Net |
|---|---|---|---|---|---|
| Stocks | 24 M | 100.0% | 163.3 K | 0 | 163.3 K |
| ETFs | 9.764 K | 0.0% | 8.849 K | 0 | 8.849 K |
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Fund Snapshot
Q4 2025
Latest filed
2/11/2026
Total value ($000)
24,005,012
Holdings
241
QoQ value change ($000)
172,097
(0.7%)
Value = total reported 13F value ($000), Holdings = number of positions.
13F Value over time
Holdings count over time
Sector allocation (latest, stocks only)
Methodology:
sector allocation is stocks-only;
instrument flow table is ex-options;
options exposure is shown separately.
Details.