Westfield Capital Management Co LP 13F holdings
Westfield Capital Management Co LP reported 275 positions with a total reported value of $30.6B as of 2026-06-30, in its 13F for Q2 2026, filed 2026-08-12. Top holdings by reported value: NVDA NVIDIA CORPORATION (5.3%), GOOGL ALPHABET INC (4.4%), ASND ASCENDIS PHARMA A/S (4.2%), AXON AXON ENTERPRISE INC (2.7%), FTAI FTAI AVIATION LTD (2.6%). Against 2026-03-31 it opened 67 new positions and exited 38. Next 13F due by 2026-11-14, the legal deadline 45 days after the quarter ending 2026-09-30.
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Top holdings
25 largest of 275 positions · reported value as of 2026-06-30
| Holding | Shares | Reported value | % of portfolio |
|---|---|---|---|
| NVDA NVIDIA CORPORATION | 8,079,926 | $1.6B | 5.3% |
| GOOGL ALPHABET INC | 3,806,691 | $1.4B | 4.4% |
| ASND ASCENDIS PHARMA A/S | 4,798,267 | $1.3B | 4.2% |
| AXON AXON ENTERPRISE INC | 1,491,490 | $836.1M | 2.7% |
| FTAI FTAI AVIATION LTD | 2,937,228 | $794.6M | 2.6% |
| AAPL APPLE INC | 2,573,774 | $744.7M | 2.4% |
| FIX COMFORT SYS USA INC | 355,433 | $704.5M | 2.3% |
| AVGO BROADCOM INC | 1,556,522 | $588.0M | 1.9% |
| MSFT MICROSOFT CORP | 1,414,294 | $527.6M | 1.7% |
| HWM HOWMET AEROSPACE INC | 1,921,476 | $516.6M | 1.7% |
| LLY ELI LILLY & CO | 416,732 | $499.8M | 1.6% |
| SNOW SNOWFLAKE INC | 1,736,498 | $441.9M | 1.4% |
| MKSI MKS INC. | 928,617 | $413.0M | 1.3% |
| META META PLATFORMS INC | 677,389 | $381.6M | 1.2% |
| VRT VERTIV HOLDINGS CO | 1,054,361 | $353.0M | 1.2% |
| GEV GE VERNOVA INC | 241,272 | $283.5M | 0.9% |
| MU MICRON TECHNOLOGY INC | 228,203 | $263.4M | 0.9% |
| V VISA INC | 762,403 | $261.6M | 0.9% |
| APG API GROUP CORP | 6,154,301 | $260.6M | 0.9% |
| TPR TAPESTRY INC | 1,696,569 | $248.3M | 0.8% |
| RYTM RHYTHM PHARMACEUTICALS INC | 2,208,595 | $245.2M | 0.8% |
| LTH LIFE TIME GROUP HOLDINGS INC | 5,995,254 | $244.8M | 0.8% |
| TSM TAIWAN SEMICONDUCTOR MANUFAC | 510,999 | $244.0M | 0.8% |
| GH GUARDANT HEALTH INC | 1,624,459 | $243.7M | 0.8% |
| QUANTA SVCS INC | 331,489 | $238.7M | 0.8% |
SEC FORM 13F · Q2 2026 · VALUES AS REPORTED, NOT PRICES
New positions this quarter
Held at 2026-06-30, not at 2026-03-31 · 67 in all · reported value as of 2026-06-30
| Holding | Shares | Reported value | % of portfolio |
|---|---|---|---|
| CRS CARPENTER TECHNOLOGY CORP | 314,082 | $193.7M | 0.6% |
| PTCT PTC THERAPEUTICS INC | 1,956,156 | $159.6M | 0.5% |
| LRCX LAM RESEARCH CORP | 285,614 | $123.8M | 0.4% |
| ASML ASML HLDG NV | 57,430 | $114.3M | 0.4% |
| SNDK SANDISK CORP | 49,024 | $111.5M | 0.4% |
| NPO ENPRO INC | 286,554 | $108.0M | 0.4% |
| FROG JFROG LTD | 1,114,561 | $101.3M | 0.3% |
| TTMI TTM TECHNOLOGIES INC | 416,052 | $77.8M | 0.3% |
| FPS FORGENT POWER SOLUTIONS INC | 1,370,928 | $76.6M | 0.3% |
| RBRK RUBRIK INC. | 937,308 | $75.2M | 0.2% |
| SPROUTS FMRS MKT INC | 866,638 | $73.3M | 0.2% |
| NUVL NUVALENT INC | 585,583 | $72.3M | 0.2% |
| DYCOM INDS INC | 141,978 | $71.8M | 0.2% |
| TER TERADYNE INC | 136,491 | $66.0M | 0.2% |
| ST SENSATA TECHNOLOGIES HLDG PL | 1,333,853 | $63.7M | 0.2% |
| BTSG BRIGHTSPRING HEALTH SVCS INC | 897,804 | $62.6M | 0.2% |
| RLAY RELAY THERAPEUTICS INC | 3,343,496 | $62.6M | 0.2% |
| BLDR BUILDERS FIRSTSOURCE INC | 656,421 | $58.7M | 0.2% |
| RBLX ROBLOX CORP | 985,802 | $53.6M | 0.2% |
| ARGX ARGENX SE | 57,082 | $53.0M | 0.2% |
| HAPPEN INC | 2,500,134 | $51.9M | 0.2% |
| FLEX FLEX LTD | 314,008 | $50.9M | 0.2% |
| SPOT SPOTIFY TECHNOLOGY S A | 110,179 | $50.6M | 0.2% |
| ADI ANALOG DEVICES INC | 126,445 | $50.2M | 0.2% |
| NDAQ NASDAQ INC | 635,713 | $50.1M | 0.2% |
Sold out
Held at 2026-03-31, gone by 2026-06-30 · 38 in all · reported value as of 2026-03-31
| Holding | Shares 2026-03-31 | Reported value | % of portfolio then |
|---|---|---|---|
| KRATOS DEFENSE & SEC SOLUTIO | 1,563,146 | $110.2M | 0.5% |
| AMERICAN INTL GROUP INC | 1,458,711 | $109.8M | 0.5% |
| PLTR PALANTIR TECHNOLOGIES INC | 674,557 | $98.7M | 0.4% |
| WGS GENEDX HOLDINGS CORP | 1,369,108 | $87.9M | 0.4% |
| FFIV F5 INC | 298,542 | $86.4M | 0.4% |
| CHRW C H ROBINSON WORLDWIDE IN | 429,500 | $71.3M | 0.3% |
| LOWES COS INC | 300,962 | $71.1M | 0.3% |
| MASIMO CORP | 341,229 | $60.7M | 0.3% |
| ZS ZSCALER INC | 427,919 | $60.0M | 0.3% |
| HUBS HUBSPOT INC | 232,976 | $56.9M | 0.2% |
| INSTALLED BLDG PRODS INC | 208,248 | $55.2M | 0.2% |
| MCO MOODYS CORP | 123,603 | $53.9M | 0.2% |
| TOPBUILD COR | 148,581 | $52.2M | 0.2% |
| KKR KKR & CO INC | 558,136 | $51.6M | 0.2% |
| TECH BIO-TECHNE CORP | 856,043 | $44.7M | 0.2% |
| FICO FAIR ISAAC CORP | 39,934 | $42.6M | 0.2% |
| IONQ IONQ INC | 1,373,788 | $39.6M | 0.2% |
| HLNE HAMILTON LANE INC | 364,174 | $36.2M | 0.2% |
| OPCH OPTION CARE HEALTH INC | 1,182,814 | $31.8M | 0.1% |
| LENDINGCLUB ISSUANCE TR SER | 2,117,543 | $30.3M | 0.1% |
| TDG TRANSDIGM GROUP INC | 12,950 | $15.0M | <0.1% |
| WFC WELLS FARGO & CO | 87,713 | $7.0M | <0.1% |
| M & T BK CORP | 29,839 | $6.2M | <0.1% |
| RJF RAYMOND JAMES FINL INC | 40,095 | $5.8M | <0.1% |
| MCD MCDONALDS CORP | 18,034 | $5.6M | <0.1% |
Biggest increases and decreases
Positions held at both quarter ends, by change in shares · reported value as of 2026-06-30
Increases
| Holding | Shares 2026-03-31 | Shares 2026-06-30 | Change | Reported value |
|---|---|---|---|---|
| GOOGL ALPHABET INC | 2,077,231 | 3,806,691 | +83.3% | $1.4B |
| NVDA NVIDIA CORPORATION | 6,317,039 | 8,079,926 | +27.9% | $1.6B |
| SNOW SNOWFLAKE INC | 718,810 | 1,736,498 | +141.6% | $441.9M |
| AXON AXON ENTERPRISE INC | 1,064,134 | 1,491,490 | +40.2% | $836.1M |
| AMD ADVANCED MICRO DEVICES INC | 5,020 | 403,081 | +7,929.5% | $234.2M |
| GILD GILEAD SCIENCES INC | 26,690 | 1,287,629 | +4,724.4% | $162.7M |
| CAT CATERPILLAR INC | 32,325 | 174,620 | +440.2% | $186.0M |
| APPLIED MATLS INC | 936 | 205,592 | +21,865.0% | $148.6M |
| MU MICRON TECHNOLOGY INC | 100,434 | 228,203 | +127.2% | $263.4M |
| AVGO BROADCOM INC | 1,236,925 | 1,556,522 | +25.8% | $588.0M |
| GRMN GARMIN LTD | 376,362 | 861,057 | +128.8% | $204.5M |
| LTH LIFE TIME GROUP HOLDINGS INC | 3,185,515 | 5,995,254 | +88.2% | $244.8M |
Decreases
| Holding | Shares 2026-03-31 | Shares 2026-06-30 | Change | Reported value |
|---|---|---|---|---|
| FIX COMFORT SYS USA INC | 620,915 | 355,433 | -42.8% | $704.5M |
| MRVL MARVELL TECHNOLOGY INC | 1,673,381 | 13,193 | -99.2% | $3.9M |
| BE BLOOM ENERGY CORP | 1,191,572 | 10,570 | -99.1% | $3.2M |
| AMZN AMAZON COM INC | 2,279,654 | 859,806 | -62.3% | $204.9M |
| ALAB ASTERA LABS INC | 860,113 | 249,299 | -71.0% | $120.4M |
| VRT VERTIV HOLDINGS CO | 1,921,696 | 1,054,361 | -45.1% | $353.0M |
| CRDO CREDO TECHNOLOGY GROUP HOLDI | 926,219 | 216,976 | -76.6% | $59.0M |
| RVMD REVOLUTION MEDICINES INC | 1,556,578 | 600,821 | -61.4% | $112.5M |
| AAPL APPLE INC | 3,133,113 | 2,573,774 | -17.9% | $744.7M |
| RCL ROYAL CARIBBEAN GROUP | 505,765 | 128,165 | -74.7% | $40.7M |
| NFLX NETFLIX INC. | 1,969,994 | 290,833 | -85.2% | $20.8M |
| TSLA TESLA INC | 316,102 | 50,411 | -84.1% | $21.2M |
CIK 1177719 · 13F FILINGS ON EDGAR · INFORMATIONAL ONLY
More 13F data
Source: U.S. Securities and Exchange Commission (EDGAR) and other official
government data · Updated 2026-10-12 ·
For informational purposes only, not investment advice.
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