WESTFIELD CAPITAL MANAGEMENT CO LP
13F Reported Value
ⓘ$30.6B
Holdings
278
Latest Filing
2026-06-30
Filing Quarter
Q2 2026
Portfolio Overview
WESTFIELD CAPITAL MANAGEMENT CO LP disclosed 278 positions worth $30.6B in its Form 13F-HR for Q2 2026, led by $NVDA (NVIDIA CORP) at 5.3% of the equity portfolio, followed by $GOOG and $ASND. During the quarter the fund opened 68 new positions and exited 40 — including a new stake in $CRS and a full exit from $KTOS. The portfolio is most concentrated in Technology (42.5% of disclosed assets). All figures are sourced directly from WESTFIELD CAPITAL MANAGEMENT CO LP’s Form 13F-HR filing with the SEC under CIK 1177719.
AI Fund Analysis
DiversifyingSector Allocation
AUM History
Top Equity Holdings by Value
Quarterly Activity — Q2 2026
Click any card to unlockTop Holdings
- 85.9#5
Quality
$1.6B8,079,926 sh - 78.2#57
Quality
$1.3B3,749,074 sh - 44.8#1,898
Quality
$1.3B4,798,267 sh - 56.6
Quality
$836.1M1,491,490 sh - —
Quality
$794.6M2,937,228 sh - 76.4
Quality
$744.7M2,573,774 sh - 77.7
Quality
$704.5M355,433 sh - 84.5
Quality
$588.0M1,556,522 sh - 79.8
Quality
$527.6M1,414,294 sh - 73.9
Quality
$516.6M1,921,476 sh
| Company | Quality | Value | Shares |
|---|---|---|---|
 NVIDIA CORP$NVDA | 85.9#5 | $1.6B | 8,079,926 |
 Alphabet Inc.$GOOG | 78.2#57 | $1.3B | 3,749,074 |
 Ascendis Pharma A/S$ASND | 44.8#1,898 | $1.3B | 4,798,267 |
 AXON ENTERPRISE, INC.$AXON | 56.6 | $836.1M | 1,491,490 |
 FTAI Aviation Ltd.$FTAI | — | $794.6M | 2,937,228 |
 Apple Inc.$AAPL | 76.4 | $744.7M | 2,573,774 |
 COMFORT SYSTEMS USA INC$FIX | 77.7 | $704.5M | 355,433 |
 Broadcom Inc.$AVGO | 84.5 | $588.0M | 1,556,522 |
 MICROSOFT CORP$MSFT | 79.8 | $527.6M | 1,414,294 |
 Howmet Aerospace Inc.$HWM | 73.9 | $516.6M | 1,921,476 |
Unlock AI quality scores for every holding
32-signal composite ranking on each of WESTFIELD CAPITAL MANAGEMENT CO LP's 278 positions.
Showing top 10 of 278 holdings.
Sector Allocation
Technology
$13.0B
Industrials
$4.9B
Healthcare
$4.8B
Financials
$2.2B
Consumer Discretionary
$2.1B
Materials
$1.2B
Energy
$759.5M
Communication Services
$572.8M
Top Holdings — WESTFIELD CAPITAL MANAGEMENT CO LP (Q2 2026)
Top 150 of 278 disclosed positions (by reported value) from the latest Form 13F-HR, with quarter-over-quarter share changes and 13F Pro quality scores. Sourced from SEC EDGAR.
| # | Ticker | Company | Value | Weight | QoQ | Quality |
|---|---|---|---|---|---|---|
| 1 | $NVDA | NVIDIA CORP | $1.6B | 5.3% | +28% | 85.9 |
| 2 | $GOOG | Alphabet Inc. | $1.3B | 4.4% | +85% | 78.2 |
| 3 | $ASND | Ascendis Pharma A/S | $1.3B | 4.2% | -0% | 44.8 |
| 4 | $AXON | AXON ENTERPRISE, INC. | $836.1M | 2.7% | +40% | 56.6 |
| 5 | $FTAI | FTAI Aviation Ltd. | $794.6M | 2.6% | +3% | — |
| 6 | $AAPL | Apple Inc. | $744.7M | 2.4% | -18% | 76.4 |
| 7 | $FIX | COMFORT SYSTEMS USA INC | $704.5M | 2.3% | -43% | 77.7 |
| 8 | $AVGO | Broadcom Inc. | $588.0M | 1.9% | +26% | 84.5 |
| 9 | $MSFT | MICROSOFT CORP | $527.6M | 1.7% | -14% | 79.8 |
| 10 | $HWM | Howmet Aerospace Inc. | $516.6M | 1.7% | -16% | 73.9 |
| 11 |  $LLY | ELI LILLY & Co | $499.8M | 1.6% | +14% | 87.5 |
| 12 |  $SNOW | Snowflake Inc. | $441.9M | 1.4% | +142% | 54.9 |
| 13 |  $MKSI | MKS INC | $413.0M | 1.4% | -11% | 61.2 |
| 14 |  $META | Meta Platforms, Inc. | $381.6M | 1.3% | +29% | 79.6 |
| 15 |  $VRT | Vertiv Holdings Co | $353.0M | 1.1% | -45% | 81 |
| 16 |  $GEV | GE Vernova Inc. | $283.5M | 0.9% | +21% | 81.1 |
| 17 |  $MU | MICRON TECHNOLOGY INC | $263.4M | 0.9% | +127% | 86.2 |
| 18 |  $V | VISA INC. | $261.6M | 0.8% | +67% | 82.9 |
| 19 |  $APG | APi Group Corp | $260.6M | 0.8% | +33% | 65.4 |
| 20 |  $TPR | TAPESTRY, INC. | $248.3M | 0.8% | -23% | 72.7 |
| 21 |  $RYTM | RHYTHM PHARMACEUTICALS, INC. | $245.2M | 0.8% | +14% | 33.9 |
| 22 |  $LTH | Life Time Group Holdings, Inc. | $244.8M | 0.8% | +88% | 60.9 |
| 23 |  $TSM | TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD | $244.0M | 0.8% | +4% | — |
| 24 |  $GH | Guardant Health, Inc. | $243.7M | 0.8% | +19% | 39 |
| 25 |  $PWR | QUANTA SERVICES, INC. | $238.7M | 0.8% | -0% | 72.1 |
| 26 |  $NOW | ServiceNow, Inc. | $235.7M | 0.8% | +70% | 72.9 |
| 27 |  $AMD | ADVANCED MICRO DEVICES INC | $234.2M | 0.8% | +7930% | 79.8 |
| 28 |  $PANW | Palo Alto Networks Inc | $224.5M | 0.7% | +3% | 65.5 |
| 29 |  $WWD | Woodward, Inc. | $224.0M | 0.7% | +93% | 67.3 |
| 30 |  $ANET | Arista Networks, Inc. | $223.7M | 0.7% | +69% | 81.9 |
| 31 |  $LPLA | LPL Financial Holdings Inc. | $223.4M | 0.7% | -10% | 72.1 |
| 32 |  $RKLB | Rocket Lab Corp | $214.9M | 0.7% | -33% | 39.9 |
| 33 |  $AS | Amer Sports, Inc. | $214.7M | 0.7% | +61% | 64 |
| 34 |  $NET | Cloudflare, Inc. | $204.9M | 0.7% | +54% | 56.4 |
| 35 |  $AMZN | AMAZON COM INC | $204.9M | 0.7% | -62% | 68.7 |
| 36 |  $GRMN | GARMIN LTD | $204.5M | 0.7% | +129% | — |
| 37 |  $RRX | REGAL REXNORD CORP | $204.1M | 0.7% | +26% | 52 |
| 38 |  $NTRA | Natera, Inc. | $197.2M | 0.6% | -4% | 53.5 |
| 39 |  $MS | MORGAN STANLEY | $196.6M | 0.6% | +89% | 75.8 |
| 40 |  $CRS | CARPENTER TECHNOLOGY CORP | $193.7M | 0.6% | NEW | 64.6 |
| 41 |  $IOT | Samsara Inc. | $189.3M | 0.6% | +15% | 68.6 |
| 42 |  $DT | Dynatrace, Inc. | $186.6M | 0.6% | +1% | 64.4 |
| 43 |  $CAT | CATERPILLAR INC | $186.0M | 0.6% | +440% | 66.5 |
| 44 |  $SMTC | SEMTECH CORP | $183.4M | 0.6% | -12% | 55.9 |
| 45 |  $AME | AMETEK INC/ | $175.1M | 0.6% | -3% | 69.7 |
| 46 |  $ABVX | Abivax S.A. | $174.5M | 0.6% | -1% | — |
| 47 |  $INSM | INSMED Inc | $173.7M | 0.6% | +11% | 39.4 |
| 48 |  $ITT | ITT INC. | $164.2M | 0.5% | +18% | 63 |
| 49 |  $GILD | GILEAD SCIENCES, INC. | $162.7M | 0.5% | +4724% | 57.4 |
| 50 |  $PTCT | PTC THERAPEUTICS, INC. | $159.6M | 0.5% | NEW | 35.4 |
| 51 |  $BROS | Dutch Bros Inc. | $156.8M | 0.5% | -6% | 63.6 |
| 52 |  $CELH | Celsius Holdings, Inc. | $155.9M | 0.5% | +41% | 66.5 |
| 53 |  $MTZ | MASTEC INC | $155.8M | 0.5% | +50% | 58.8 |
| 54 |  $SN | SharkNinja, Inc. | $153.5M | 0.5% | +11% | 66.8 |
| 55 |  $CSX | CSX CORP | $149.9M | 0.5% | +90% | 65.2 |
| 56 |  $FCFS | FirstCash Holdings, Inc. | $149.9M | 0.5% | +60% | 69.3 |
| 57 |  $KEY | KEYCORP /NEW/ | $149.7M | 0.5% | +25% | 70.8 |
| 58 |  $MCHP | MICROCHIP TECHNOLOGY INC | $149.5M | 0.5% | +69% | 52.9 |
| 59 |  $AMAT | APPLIED MATERIALS INC /DE | $148.6M | 0.5% | NEW | 72.3 |
| 60 |  $MAR | MARRIOTT INTERNATIONAL INC /MD/ | $147.9M | 0.5% | +160% | 61.7 |
| 61 |  $PCVX | Vaxcyte, Inc. | $143.7M | 0.5% | -32% | — |
| 62 |  $GL | GLOBE LIFE INC. | $137.8M | 0.5% | -8% | 66 |
| 63 |  $FTI | TechnipFMC plc | $136.6M | 0.5% | +1% | — |
| 64 |  $XPO | XPO, Inc. | $129.1M | 0.4% | +10% | 58.4 |
| 65 |  $LEGN | Legend Biotech Corp | $127.9M | 0.4% | -23% | 47.8 |
| 66 | — | EVERPURE INC - CL A | $127.0M | 0.4% | -14% | — |
| 67 |  $LRCX | LAM RESEARCH CORP | $123.8M | 0.4% | NEW | 79.4 |
| 68 |  $JLL | JONES LANG LASALLE INC | $123.5M | 0.4% | +15% | 64.2 |
| 69 |  $ALAB | Astera Labs, Inc. | $120.4M | 0.4% | -71% | 75.1 |
| 70 |  $ROK | ROCKWELL AUTOMATION, INC | $117.4M | 0.4% | +15% | 63.6 |
| 71 |  $IEX | IDEX CORP /DE/ | $116.6M | 0.4% | +21% | 60.9 |
| 72 |  $COHR | COHERENT CORP. | $114.8M | 0.4% | -27% | 58.5 |
| 73 |  $LGN | Legence Corp. | $114.4M | 0.4% | -28% | 64.1 |
| 74 |  $LECO | LINCOLN ELECTRIC HOLDINGS INC | $114.4M | 0.4% | +20% | 60.1 |
| 75 |  $ASML | ASML HOLDING NV | $114.3M | 0.4% | NEW | — |
| 76 |  $PL | Planet Labs PBC | $113.6M | 0.4% | +109% | 38.4 |
| 77 |  $ONTO | ONTO INNOVATION INC. | $113.3M | 0.4% | -8% | 61.9 |
| 78 |  $COR | Cencora, Inc. | $113.2M | 0.4% | -8% | 61.1 |
| 79 |  $RVMD | Revolution Medicines, Inc. | $112.5M | 0.4% | -61% | — |
| 80 |  $SNDK | Sandisk Corp | $111.5M | 0.4% | NEW | 87.7 |
| 81 |  $AFRM | Affirm Holdings, Inc. | $110.3M | 0.4% | +25% | 81.3 |
| 82 |  $LYV | Live Nation Entertainment, Inc. | $108.2M | 0.3% | -27% | 52.9 |
| 83 |  $NPO | Enpro Inc. | $108.0M | 0.3% | NEW | 55 |
| 84 |  $PR | Permian Resources Corp | $106.0M | 0.3% | -23% | 79.5 |
| 85 |  $ARES | Ares Management Corp | $106.0M | 0.3% | -39% | 60.9 |
| 86 |  $IMAX | IMAX CORP | $105.8M | 0.3% | +13% | 59.6 |
| 87 |  $GWRE | Guidewire Software, Inc. | $103.3M | 0.3% | +72% | 67.3 |
| 88 |  $NXT | Nextpower Inc. | $102.2M | 0.3% | -23% | 69.1 |
| 89 |  $FROG | JFrog Ltd | $101.3M | 0.3% | NEW | — |
| 90 |  $SNPS | SYNOPSYS INC | $101.2M | 0.3% | +71% | 67.9 |
| 91 |  $ROKU | ROKU, INC | $99.0M | 0.3% | -39% | 66.7 |
| 92 |  $PLXS | PLEXUS CORP | $96.8M | 0.3% | -16% | 62.5 |
| 93 |  $AIT | APPLIED INDUSTRIAL TECHNOLOGIES INC | $96.6M | 0.3% | -1% | 58.7 |
| 94 |  $MSCI | MSCI Inc. | $96.3M | 0.3% | -26% | 75.7 |
| 95 |  $HOOD | Robinhood Markets, Inc. | $95.8M | 0.3% | +51% | 82.1 |
| 96 |  $ROST | ROSS STORES, INC. | $94.2M | 0.3% | -6% | 70.4 |
| 97 |  $ADPT | Adaptive Biotechnologies Corp | $91.5M | 0.3% | -22% | 41.4 |
| 98 |  $XENE | Xenon Pharmaceuticals Inc. | $91.0M | 0.3% | +8% | 24 |
| 99 |  $ORLY | O REILLY AUTOMOTIVE INC | $85.9M | 0.3% | +5% | 67.4 |
| 100 |  $C | CITIGROUP INC | $85.1M | 0.3% | +1268% | 65 |
| 101 |  $PKG | PACKAGING CORP OF AMERICA | $84.9M | 0.3% | +17% | 63 |
| 102 |  $BIRK | Birkenstock Holding plc | $84.6M | 0.3% | -16% | — |
| 103 |  $PLMR | Palomar Holdings, Inc. | $84.5M | 0.3% | -22% | 70 |
| 104 |  $EWBC | EAST WEST BANCORP INC | $83.9M | 0.3% | -19% | 65.6 |
| 105 |  $RRR | Red Rock Resorts, Inc. | $82.1M | 0.3% | +3% | 57.8 |
| 106 |  $WTFC | WINTRUST FINANCIAL CORP | $81.0M | 0.3% | +11% | 60.3 |
| 107 |  $CLH | CLEAN HARBORS INC | $80.2M | 0.3% | +3% | 55.6 |
| 108 |  $CWST | CASELLA WASTE SYSTEMS INC | $78.8M | 0.3% | -1% | 57.1 |
| 109 |  $TTMI | TTM TECHNOLOGIES INC | $77.8M | 0.3% | NEW | 62.6 |
| 110 |  $TRGP | Targa Resources Corp. | $77.0M | 0.3% | -6% | 63.3 |
| 111 |  $FPS | Forgent Power Solutions, Inc. | $76.6M | 0.3% | NEW | — |
| 112 |  $ALNY | ALNYLAM PHARMACEUTICALS, INC. | $76.0M | 0.3% | +3% | 71.4 |
| 113 |  $COCO | Vita Coco Company, Inc. | $75.3M | 0.3% | -1% | 63.1 |
| 114 |  $RBRK | Rubrik, Inc. | $75.2M | 0.3% | NEW | 56.6 |
| 115 |  $AZO | AUTOZONE INC | $74.8M | 0.2% | -18% | 66.2 |
| 116 |  $DASH | DoorDash, Inc. | $74.1M | 0.2% | -10% | 71 |
| 117 |  $WYNN | WYNN RESORTS LTD | $73.9M | 0.2% | +3% | — |
| 118 |  $IDXX | IDEXX LABORATORIES INC /DE | $73.7M | 0.2% | +5% | 73.8 |
| 119 |  $SFM | Sprouts Farmers Market, Inc. | $73.3M | 0.2% | NEW | 64.8 |
| 120 |  $PRAX | Praxis Precision Medicines, Inc. | $73.3M | 0.2% | NEW | — |
| 121 |  $CRM | Salesforce, Inc. | $73.2M | 0.2% | +72% | 77 |
| 122 |  $PRIM | Primoris Services Corp | $73.1M | 0.2% | -1% | 51.8 |
| 123 |  $NUVL | Nuvalent, Inc. | $72.3M | 0.2% | NEW | — |
| 124 |  $DY | DYCOM INDUSTRIES INC | $71.8M | 0.2% | NEW | 56.3 |
| 125 |  $STEP | StepStone Group Inc. | $71.5M | 0.2% | +47% | 45.2 |
| 126 |  $JBHT | HUNT J B TRANSPORT SERVICES INC | $71.1M | 0.2% | +8% | 60.2 |
| 127 |  $VST | Vistra Corp. | $70.7M | 0.2% | -10% | 71.9 |
| 128 |  $GKOS | GLAUKOS Corp | $67.6M | 0.2% | +0% | 40.5 |
| 129 |  $MTSI | MACOM Technology Solutions Holdings, Inc. | $66.9M | 0.2% | +33% | 69.4 |
| 130 |  $TER | TERADYNE, INC | $66.0M | 0.2% | NEW | 77.3 |
| 131 |  $SAIA | SAIA INC | $64.7M | 0.2% | -1% | 58.2 |
| 132 |  $NXPI | NXP Semiconductors N.V. | $63.9M | 0.2% | -8% | — |
| 133 |  $ST | Sensata Technologies Holding plc | $63.7M | 0.2% | NEW | — |
| 134 |  $HQY | HEALTHEQUITY, INC. | $63.5M | 0.2% | -1% | 71.2 |
| 135 |  $BTSG | BrightSpring Health Services, Inc. | $62.6M | 0.2% | NEW | 63.3 |
| 136 |  $RLAY | Relay Therapeutics, Inc. | $62.6M | 0.2% | NEW | 19.5 |
| 137 |  $HLI | HOULIHAN LOKEY, INC. | $62.2M | 0.2% | -15% | 67.8 |
| 138 |  $ENTG | ENTEGRIS INC | $62.0M | 0.2% | -7% | 58 |
| 139 |  $CORZ | Core Scientific, Inc./tx | $61.7M | 0.2% | +63% | 14.1 |
| 140 |  $RDNT | RadNet, Inc. | $60.2M | 0.2% | +83% | 58.6 |
| 141 |  $ORKA | Oruka Therapeutics, Inc. | $60.1M | 0.2% | +102% | — |
| 142 |  $CRDO | Credo Technology Group Holding Ltd | $59.0M | 0.2% | -77% | 55.1 |
| 143 |  $BLDR | Builders FirstSource, Inc. | $58.7M | 0.2% | NEW | 45.9 |
| 144 |  $LSCC | LATTICE SEMICONDUCTOR CORP | $58.4M | 0.2% | -32% | 48.7 |
| 145 |  $DSGX | DESCARTES SYSTEMS GROUP INC | $57.8M | 0.2% | +4% | — |
| 146 |  $AVNT | AVIENT CORP | $57.3M | 0.2% | -1% | 55 |
| 147 |  $BRZE | Braze, Inc. | $56.8M | 0.2% | -34% | 47.4 |
| 148 |  $FN | Fabrinet | $54.7M | 0.2% | -66% | 62.8 |
| 149 |  $LNG | Cheniere Energy, Inc. | $54.6M | 0.2% | -50% | 66.5 |
| 150 |  $PODD | INSULET CORP | $53.7M | 0.2% | NEW | 71.3 |
New Positions (68)
$CRS CARPENTER TECHNOLOGY CORP$193.7M$PTCT PTC THERAPEUTICS, INC.$159.6M$LRCX LAM RESEARCH CORP$123.8M$ASML ASML HOLDING NV$114.3M$SNDK Sandisk Corp$111.5M$NPO Enpro Inc.$108.0M$FROG JFrog Ltd$101.3M$TTMI TTM TECHNOLOGIES INC$77.8M$FPS Forgent Power Solutions, Inc.$76.6M$RBRK Rubrik, Inc.$75.2M$SFM Sprouts Farmers Market, Inc.$73.3M$NUVL Nuvalent, Inc.$72.3M$DY DYCOM INDUSTRIES INC$71.8M$TER TERADYNE, INC$66.0M$ST Sensata Technologies Holding plc$63.7MExited Positions (40)
$KTOS KRATOS DEFENSE & SECURITY SOLUTIONS, INC.
$AIG AMERICAN INTERNATIONAL GROUP, INC.
$PLTR Palantir Technologies Inc.
$WGS GeneDx Holdings Corp.
$FFIV F5, INC.
$CHRW C. H. ROBINSON WORLDWIDE, INC.
$LOW LOWES COMPANIES INC
$MASI MASIMO CORP
$ZS Zscaler, Inc.
$HUBS HUBSPOT INC
$IBP Installed Building Products, Inc.
$MCO MOODYS CORP /DE/
$BLD QXO Insulation, LLC
$KKR KKR & Co. Inc.
$TECH BIO-TECHNE CorpBrowse Top Institutional Investors
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