Westfield Capital Management Co. LP
In its 13F for Q2 2025 (holdings as of June 30, 2025, filed August 12, 2025), Westfield Capital Management Co. LP reported 239 stock positions worth $23.8 billion. Its top holding was Nvidia (NVDA) at 5.0% of the portfolio, followed by Ascendis Pharma A/S (ASND, 3.9%) and Microsoft (MSFT, 3.7%). Compared with Q1 2025, it opened 38 new positions, sold out of 43, added to 72 and reduced 115. The biggest buy was Nvidia (NVDA, shares +3%) and the biggest sale Palantir Technologies Class A (PLTR, shares −100%).
- Most Recent 13F
- Q2 2026
- Location
- BOSTON, MA
- CIK
- 0001177719
- Portfolio Value
- $23.8B (Q2 2025)
- SEC Filing
- 0001085146-25-004820 ↗ filed Aug 12, 2025
Holdings Value
Holdings 239 stocks · $23.8B
| NVDA Nvidia Corp. | 5.00% | 7,545,345 | $1.2B | Add +2.8% |
| ASND Ascendis Pharma A/S | 3.95% | 5,451,401 | $940.9M | Reduce -0.5% |
| MSFT Microsoft Corp. | 3.67% | 1,757,424 | $874.2M | Reduce -4.1% |
| AAPL Apple Inc. | 3.01% | 3,494,184 | $716.9M | Add +2.7% |
| AMZN Amazon.com Inc. | 2.85% | 3,100,452 | $680.2M | Reduce -10.5% |
| AXON Axon Enterprise Inc. | 2.74% | 790,079 | $654.1M | Reduce -14.8% |
| META Meta Platforms Inc. Class A | 2.66% | 858,402 | $633.6M | Reduce -4.5% |
| FIX Comfort Systems USA Inc. | 2.11% | 936,412 | $502.1M | Add +5.3% |
| GOOGL Alphabet Inc. Class A | 1.90% | 2,571,637 | $453.2M | Reduce -25.7% |
| TDG Transdigm Group Inc. | 1.85% | 290,013 | $441.0M | Reduce -8.3% |
| AVGO Broadcom Inc. | 1.54% | 1,336,142 | $368.3M | Reduce -4.5% |
| HWM Howmet Aerospace Inc. | 1.50% | 1,915,955 | $356.6M | Add +68.8% |
| VRT Vertiv Holdings Co. Class A | 1.42% | 2,637,409 | $338.7M | Add +10.9% |
| NFLX Netflix Inc. | 1.41% | 251,923 | $337.4M | Add +17.8% |
| NOW ServiceNow Inc. | 1.29% | 298,276 | $306.7M | Reduce -6.9% |
| TPR Tapestry Inc. | 1.26% | 3,419,245 | $300.2M | Reduce -5.1% |
| LPLA LPL Financial Holdings Inc. | 1.23% | 782,232 | $293.3M | Reduce -5.8% |
| V Visa Inc. Class A | 1.19% | 796,463 | $282.8M | Reduce -11.9% |
| LLY Eli Lilly & Co. | 1.01% | 307,493 | $239.7M | Add +18.8% |
| LEGN Legend Biotech Corp.-ADR | 0.96% | 6,472,547 | $229.7M | Reduce -6.4% |
| EAT Brinker International Inc. | 0.94% | 1,236,583 | $223.0M | Add +24.2% |
| FTAI Ftai Aviation Ltd. | 0.92% | 1,915,411 | $220.3M | Add +1.2% |
| DXCM Dexcom Inc. | 0.87% | 2,380,238 | $207.8M | Reduce -2.8% |
| MNDY Monday.com Ltd. | 0.85% | 646,320 | $203.3M | Reduce -2.8% |
| BAC Bank of America Corp. filed as BANK AMERICA CORP | 0.84% | 4,217,760 | $199.6M | Add +26.1% |
| MASI Masimo Corp. | 0.83% | 1,181,203 | $198.7M | Add +75.9% |
| FN Fabrinet | 0.82% | 663,310 | $195.5M | Add +102.8% |
| ARES Ares Management Corp. Class A | 0.78% | 1,078,769 | $186.8M | Reduce -4.4% |
| CWST Casella Waste Systems Inc. Class A | 0.75% | 1,552,307 | $179.1M | Add +3.0% |
| CRM Salesforce Inc. | 0.74% | 647,474 | $176.6M | Reduce -17.3% |
| GEV GE Vernova Inc. | 0.72% | 325,288 | $172.1M | Reduce -36.6% |
| DT Dynatrace Inc. | 0.68% | 2,951,726 | $163.0M | Add +1.4% |
| CHKP Check Point Software Tech | 0.63% | 678,958 | $150.2M | Reduce -21.5% |
| BMI Badger Meter Inc. | 0.63% | 612,809 | $150.1M | Add +78.1% |
| ORCL Oracle Corp. | 0.62% | 678,940 | $148.4M | Reduce -2.8% |
| COST Costco Wholesale Corp. | 0.60% | 144,626 | $143.2M | Reduce -2.4% |
| AZO AutoZone Inc. | 0.59% | 38,182 | $141.7M | New |
| IOT Samsara Inc. Class A | 0.59% | 3,549,106 | $141.2M | Add +0.7% |
| TSLA Tesla Inc. | 0.58% | 438,413 | $139.3M | Reduce -7.7% |
| SN Sharkninja Inc. | 0.58% | 1,404,751 | $139.1M | Add +14.2% |
| INSM Insmed Inc. | 0.57% | 1,339,288 | $134.8M | Reduce -4.8% |
| HQY Healthequity Inc. | 0.56% | 1,265,208 | $132.5M | Add +124.6% |
| TXRH Texas Roadhouse Inc. | 0.55% | 705,622 | $132.2M | Add +0.5% |
| TSM Taiwan Semiconductor-SP ADR | 0.55% | 580,313 | $131.4M | Reduce -11.4% |
| AMAT Applied Materials Inc. | 0.53% | 694,431 | $127.1M | Add +13360.6% |
| RRX Regal Rexnord Corp. | 0.53% | 870,131 | $126.1M | Reduce -13.1% |
| SMTC Semtech Corp. | 0.52% | 2,747,260 | $124.0M | Add +107.8% |
| LNTH Lantheus Holdings Inc. | 0.51% | 1,495,072 | $122.4M | Reduce -5.9% |
| GKOS Glaukos Corp. | 0.51% | 1,167,853 | $120.6M | Add +7.7% |
| PGR Progressive Corp. | 0.50% | 450,331 | $120.2M | Reduce -36.8% |
| RBLX Roblox Corp. Class A | 0.50% | 1,141,073 | $120.0M | New |
| SLNO Soleno Therapeutics Inc. | 0.50% | 1,429,756 | $119.8M | Add +18.0% |
| DKNG Draftkings Inc. Class A | 0.48% | 2,643,325 | $113.4M | Reduce -37.4% |
| NTRA Natera Inc. | 0.47% | 669,889 | $113.2M | Reduce -3.1% |
| RCL Royal Caribbean Cruises Ltd. | 0.46% | 352,525 | $110.4M | New |
| IP International Paper Co. | 0.46% | 2,323,693 | $108.8M | Add +9.7% |
| APO Apollo Global Management Inc. | 0.45% | 761,721 | $108.1M | Add +54.3% |
| MRUS Merus NV | 0.45% | 2,042,388 | $107.4M | Add +36.0% |
| ROL Rollins Inc. | 0.44% | 1,878,134 | $106.0M | Add +1923.1% |
| ITT Itt Inc. | 0.43% | 657,250 | $103.1M | Add +3.4% |
| RYTM Rhythm Pharmaceuticals Inc. | 0.43% | 1,629,468 | $103.0M | Add +21.5% |
| PCOR Procore Technologies Inc. | 0.43% | 1,504,787 | $103.0M | Reduce -19.9% |
| AJG Arthur J Gallagher & Co. filed as GALLAGHER ARTHUR J & CO | 0.43% | 321,606 | $103.0M | Reduce -0.9% |
| LYV Live Nation Entertainment Inc. | 0.43% | 677,730 | $102.5M | Add +110.2% |
| MTSI Macom Technology Solutions H | 0.43% | 709,433 | $101.7M | Reduce -1.7% |
| VST Vistra Corp. | 0.42% | 519,286 | $100.6M | Add +56.3% |
| TWLO Twilio Inc. Class A | 0.42% | 806,789 | $100.3M | Reduce -1.5% |
| GLOB Globant SA | 0.42% | 1,100,526 | $100.0M | Add +34.1% |
| PCVX Vaxcyte Inc. | 0.42% | 3,068,898 | $99.8M | Add +42.4% |
| KD Kyndryl Holdings Inc. | 0.42% | 2,375,354 | $99.7M | Reduce -18.4% |
| OPCH Option Care Health Inc. | 0.42% | 3,061,474 | $99.4M | Reduce -26.1% |
| OWL Blue Owl Capital Inc. | 0.42% | 5,152,460 | $99.0M | Reduce -7.2% |
| ROKU Roku Inc. | 0.40% | 1,097,707 | $96.5M | Reduce -1.8% |
| HEI.A Heico Corp. Class A | 0.39% | 361,062 | $93.4M | Add +1693.7% |
| UNP Union Pacific Corp. | 0.39% | 400,295 | $92.1M | Reduce -6.2% |
| PRCT Procept Biorobotics Corp. | 0.39% | 1,598,349 | $92.1M | Add +113.5% |
| DASH DoorDash Inc. Class A | 0.38% | 368,152 | $90.8M | New |
| NET Cloudflare Inc. Class A | 0.37% | 448,696 | $87.9M | New |
| RYAN Ryan Specialty Holdings Inc. | 0.36% | 1,279,815 | $87.0M | Add +18.7% |
| IT Gartner Inc. | 0.36% | 212,927 | $86.1M | Add +1381.8% |
| RKLB Rocket Lab Corp. | 0.35% | 2,365,048 | $84.6M | Reduce -8.6% |
| KMPR Kemper Corp. | 0.35% | 1,310,206 | $84.6M | Add +9.9% |
| SNOW Snowflake Inc. | 0.35% | 373,623 | $83.6M | New |
| MSCI MSCI Inc. | 0.35% | 144,360 | $83.3M | Reduce -17.8% |
| BIRK Birkenstock Holding PLC | 0.35% | 1,676,950 | $82.5M | Add +6.6% |
| KEY Keycorp | 0.34% | 4,678,788 | $81.5M | Add +57.6% |
| TRU Transunion | 0.34% | 922,286 | $81.2M | Add +11.1% |
| ICE Intercontinental Exchange Inc. | 0.34% | 440,726 | $80.9M | New |
| COR Cencora Inc. | 0.34% | 268,752 | $80.6M | Reduce -7.0% |
| SFM Sprouts Farmers Market Inc. | 0.33% | 478,370 | $78.8M | Add +1.8% |
| WSC Willscot Holdings Corp. | 0.33% | 2,861,031 | $78.4M | Add +2.1% |
| FICO Fair Isaac Corp. | 0.32% | 42,304 | $77.3M | Reduce -13.4% |
| IEX Idex Corp. | 0.32% | 438,664 | $77.0M | Reduce -1.5% |
| UNH Unitedhealth Group Inc. | 0.30% | 230,033 | $71.8M | Reduce -2.6% |
| NXT Nextpower Inc. filed as NEXTRACKER INC | 0.30% | 1,317,564 | $71.6M | Add +6.0% |
| AME Ametek Inc. | 0.30% | 395,416 | $71.6M | Reduce -2.8% |
| ROK Rockwell Automation Inc. | 0.30% | 214,680 | $71.3M | Reduce -2.4% |
| PINS Pinterest Inc. Class A | 0.30% | 1,986,093 | $71.2M | New |
| TOST Toast Inc. Class A | 0.30% | 1,602,654 | $71.0M | Add +596.9% |
| HUBS HubSpot Inc. | 0.29% | 125,407 | $69.8M | Reduce -24.8% |
Portfolio Sells Q1 2025 → Q2 2025
| PLTR Palantir Technologies Inc. Class A | Reduce -99.6% | 0.00% | −0.78 |
| GOOGL Alphabet Inc. Class A | Reduce -25.7% | 1.90% | −0.70 |
| DKS Dick's Sporting Goods Inc. | Sold out | 0.00% | −0.62 |
| TEAM Atlassian Corp. Class A | Reduce -72.0% | 0.18% | −0.58 |
| PGR Progressive Corp. | Reduce -36.8% | 0.50% | −0.48 |
| FLEX Flex Ltd. | Sold out | 0.00% | −0.46 |
| SAIA Saia Inc. | Reduce -53.7% | 0.20% | −0.44 |
| PODD Insulet Corp. | Reduce -60.5% | 0.28% | −0.41 |
| APP AppLovin Corp. Class A | Reduce -99.6% | 0.00% | −0.38 |
| SPGI S&P Global Inc. | Sold out | 0.00% | −0.37 |
| V Visa Inc. Class A | Reduce -11.9% | 1.19% | −0.36 |
| AMZN Amazon.com Inc. | Reduce -10.5% | 2.85% | −0.35 |
| MDB Mongodb Inc. | Reduce -55.7% | 0.29% | −0.34 |
| CHKP Check Point Software Tech | Reduce -21.5% | 0.63% | −0.33 |
| NU Nu Holdings Ltd./Cayman Isl-A | Sold out | 0.00% | −0.32 |
| DDOG Datadog Inc. Class A | Sold out | 0.00% | −0.31 |
| UNH Unitedhealth Group Inc. | Reduce -2.6% | 0.30% | −0.30 |
| S Sentinelone Inc. Class A | Sold out | 0.00% | −0.29 |
| OPCH Option Care Health Inc. | Reduce -26.1% | 0.42% | −0.29 |
| CRM Salesforce Inc. | Reduce -17.3% | 0.74% | −0.28 |
| TDG Transdigm Group Inc. | Reduce -8.3% | 1.85% | −0.28 |
| LRCX Lam Research Corp. | Sold out | 0.00% | −0.26 |
| AVY Avery Dennison Corp. | Reduce -71.1% | 0.08% | −0.26 |
| CYTK Cytokinetics Inc. | Sold out | 0.00% | −0.26 |
| WNS WNS Holdings Ltd. | Sold out | 0.00% | −0.25 |
| COIN Coinbase Global Inc. Class A | Sold out | 0.00% | −0.24 |
| LNTH Lantheus Holdings Inc. | Reduce -5.9% | 0.51% | −0.24 |
| TER Teradyne Inc. | Sold out | 0.00% | −0.23 |
| ASND Ascendis Pharma A/S | Reduce -0.5% | 3.95% | −0.21 |
| DKNG Draftkings Inc. Class A | Reduce -37.4% | 0.48% | −0.21 |
| TECH Bio-Techne Corp. | Reduce -98.6% | 0.00% | −0.19 |
| FOUR SHIFT4 Payments Inc. Class A | Reduce -43.0% | 0.28% | −0.19 |
| CHX Championx Corp. | Sold out | 0.00% | −0.19 |
| TTD Trade Desk Inc./the Class A | Sold out | 0.00% | −0.19 |
| CHDN Churchill Downs Inc. | Sold out | 0.00% | −0.19 |
| MOG.A Moog Inc. Class A | Sold out | 0.00% | −0.18 |
| SLAB Silicon Laboratories Inc. | Sold out | 0.00% | −0.18 |
| CRWD CrowdStrike Holdings Inc. Class A | Sold out | 0.00% | −0.18 |
| TW Tradeweb Markets Inc. Class A | Reduce -28.9% | 0.27% | −0.18 |
| LEGN Legend Biotech Corp.-ADR | Reduce -6.4% | 0.96% | −0.18 |
| PCOR Procore Technologies Inc. | Reduce -19.9% | 0.43% | −0.17 |
| HUBS HubSpot Inc. | Reduce -24.8% | 0.29% | −0.17 |
| DAY Dayforce Inc. | Sold out | 0.00% | −0.17 |
| EWBC East West Bancorp Inc. | Reduce -42.3% | 0.20% | −0.16 |
| RCKT Rocket Pharmaceuticals Inc. | Sold out | 0.00% | −0.16 |
| PR Permian Resources Corp. Class A | Reduce -34.2% | 0.19% | −0.15 |
| PLMR Palomar Holdings Inc. | Reduce -34.0% | 0.26% | −0.15 |
| JBHT Hunt (jb) Transprt SVCS Inc. | Reduce -31.6% | 0.19% | −0.14 |
| HOOD Robinhood Markets Inc. Class A | Reduce -72.9% | 0.15% | −0.14 |
| ALAB Astera Labs Inc. | Sold out | 0.00% | −0.14 |
Portfolio Buys Q1 2025 → Q2 2025
| NVDA Nvidia Corp. | Add +2.8% | 5.00% | +1.13 |
| HWM Howmet Aerospace Inc. | Add +68.8% | 1.50% | +0.78 |
| FIX Comfort Systems USA Inc. | Add +5.3% | 2.11% | +0.71 |
| AZO AutoZone Inc. | New | 0.59% | +0.59 |
| VRT Vertiv Holdings Co. Class A | Add +10.9% | 1.42% | +0.58 |
| AMAT Applied Materials Inc. | Add +13360.6% | 0.53% | +0.53 |
| FN Fabrinet | Add +102.8% | 0.82% | +0.51 |
| RBLX Roblox Corp. Class A | New | 0.50% | +0.50 |
| RCL Royal Caribbean Cruises Ltd. | New | 0.46% | +0.46 |
| NFLX Netflix Inc. | Add +17.8% | 1.41% | +0.44 |
| ROL Rollins Inc. | Add +1923.1% | 0.44% | +0.42 |
| DASH DoorDash Inc. Class A | New | 0.38% | +0.38 |
| HEI.A Heico Corp. Class A | Add +1693.7% | 0.39% | +0.37 |
| NET Cloudflare Inc. Class A | New | 0.37% | +0.37 |
| SNOW Snowflake Inc. | New | 0.35% | +0.35 |
| ICE Intercontinental Exchange Inc. | New | 0.34% | +0.34 |
| IT Gartner Inc. | Add +1381.8% | 0.36% | +0.33 |
| HQY Healthequity Inc. | Add +124.6% | 0.56% | +0.31 |
| BMI Badger Meter Inc. | Add +78.1% | 0.63% | +0.31 |
| PINS Pinterest Inc. Class A | New | 0.30% | +0.30 |
| SMTC Semtech Corp. | Add +107.8% | 0.52% | +0.30 |
| MASI Masimo Corp. | Add +75.9% | 0.83% | +0.29 |
| VEEV Veeva Systems Inc. Class A | New | 0.27% | +0.27 |
| PWR Quanta Services Inc. | New | 0.27% | +0.27 |
| TOST Toast Inc. Class A | Add +596.9% | 0.30% | +0.26 |
| CVLT Commvault Systems Inc. | New | 0.24% | +0.24 |
| SNPS Synopsys Inc. | New | 0.23% | +0.23 |
| VST Vistra Corp. | Add +56.3% | 0.42% | +0.23 |
| ORLY O'reilly Automotive Inc. | New | 0.23% | +0.23 |
| LYV Live Nation Entertainment Inc. | Add +110.2% | 0.43% | +0.23 |
| FITB Fifth Third Bancorp | New | 0.22% | +0.22 |
| VRNA Verona Pharma Ltd. | New | 0.21% | +0.21 |
| EAT Brinker International Inc. | Add +24.2% | 0.94% | +0.21 |
| BURL Burlington Stores Inc. | New | 0.21% | +0.21 |
| AFRM Affirm Holdings Inc. | New | 0.20% | +0.20 |
| XPO Xpo Inc. | New | 0.20% | +0.20 |
| CLH Clean Harbors Inc. | New | 0.19% | +0.19 |
| ENTG Entegris Inc. | New | 0.18% | +0.18 |
| PRCT Procept Biorobotics Corp. | Add +113.5% | 0.39% | +0.17 |
| COHR Coherent Corp. | Add +95.8% | 0.29% | +0.16 |
| INTA Intapp Inc. | New | 0.16% | +0.16 |
| BAC Bank of America Corp. | Add +26.1% | 0.84% | +0.16 |
| ALKT Alkami Technology Inc. | New | 0.15% | +0.15 |
| MRUS Merus NV | Add +36.0% | 0.45% | +0.14 |
| CORZ Core Scientific Inc. | New | 0.14% | +0.14 |
| TRGP Targa Resources Corp. | New | 0.14% | +0.14 |
| WGS Genedx Holdings Corp. | Add +164.8% | 0.23% | +0.13 |
| APO Apollo Global Management Inc. | Add +54.3% | 0.45% | +0.12 |
| IONQ Ionq Inc. | New | 0.12% | +0.12 |
| KNSL Kinsale Capital Group Inc. | Add +127.4% | 0.24% | +0.12 |
All Filings
| Quarter | Positions | 13F Reported Value | Top Holdings |
|---|---|---|---|
| Q2 2026 | 278 | $30.6B | NVDA, GOOGL, ASND, AXON, FTAI |
| Q1 2026 | 250 | $23.8B | NVDA, ASND, FIX, AAPL, FTAI |
| Q4 2025 | 241 | $24.0B | NVDA, ASND, AAPL, MSFT, GOOGL |
| Q3 2025 | 235 | $23.8B | NVDA, ASND, MSFT, AAPL, FIX |
| Q2 2025 | 239 | $23.8B | NVDA, ASND, MSFT, AAPL, AMZN |
| Q1 2025 | 244 | $20.5B | ASND, NVDA, AAPL, MSFT, AMZN |
| Q4 2024 | 239 | $23.0B | NVDA, AAPL, MSFT, ASND, AMZN |
| Q3 2024 | 247 | $22.1B | NVDA, AAPL, MSFT, ASND, AMZN |
| Q2 2024 | 248 | $20.4B | NVDA, MSFT, AAPL, ASND, AMZN |
| Q1 2024 | 244 | $19.0B | MSFT, ASND, AAPL, NVDA, AMZN |