Stocks/Funds/CIK 1177719

WESTFIELD CAPITAL MANAGEMENT CO LP

long-term holder
Quarterly 13F filings · Latest period 2026-03-31 · CIK 1177719
Assets
$23.59B
+15.4% YoY
Holdings
249
Lifetime alpha vs market
+11.39% annual
Average hold time
3.4 yr
median 2.5 yr

Quarterly history

Cum return +205% vs S&P +83% · α +122% lifetimeAUM $23.6B · peak $23.9BFlow $-88M (-0%)2016-062017-122019-062020-122022-062023-122025-062026-03
AUM ($B)fundS&P 500(gap = α)/ Flow in/out

Behavior signals (lifetime)

Dip response
-1.51%
trims when stocks drop
when a holding falls −10%+
Middle response
-4.24%
baseline attrition
Rally response
-13.04%
trims into rallies
when a holding rises +10%+

Top positions · 30

Ticker$ value% portYoYHold time
NVDANVIDIA Corporation$1.10B4.7%+60.9%6.5 yr
$1.10B4.7%8.0 yr
FIXComfort Systems USA, Inc$856M3.6%+329.0%2.5 yr
AAPLApple Inc.$795M3.4%+14.7%10.5 yr
$698M3.0%2.0 yr
MSFTMicrosoft Corporation$611M2.6%-0.6%10.5 yr
GOOGLAlphabet Inc.$583M2.5%10.5 yr
HWMHowmet Aerospace Inc.$528M2.2%+78.1%1.3 yr
VRTVertiv Holdings Co$482M2.0%+247.5%2.8 yr
AMZNAmazon.com, Inc.$475M2.0%+9.5%10.5 yr
AXONAxon Enterprise, Inc.$452M1.9%-19.3%3.5 yr
AVGOBroadcom Inc.$383M1.6%+86.0%7.8 yr
LLYEli Lilly and Company$335M1.4%+12.2%5.0 yr
TPRTapestry, Inc.$310M1.3%+103.3%5.3 yr
METAMeta Platforms, Inc.$301M1.3%-0.4%10.3 yr

Portfolio composition (YoY)

Industry mix
Semiconductors10.0%+2.3pp$2.35B
Unknown9.0%+2.5pp$2.12B
Engineering & Construction6.7%+5.0pp$1.57B
Aerospace & Defense6.5%+1.0pp$1.53B
Software - Infrastructure6.1%-2.8pp$1.44B
Biotechnology4.8%+0.8pp$1.13B
Internet Content & Information4.1%-1.4pp$966M
Software - Application4.0%-3.5pp$933M
Consumer Electronics3.9%-0.0pp$929M
Electrical Equipment & Parts3.4%+2.2pp$803M
Country
US86.7%+0.7pp
Unknown9.0%+2.5pp
CA1.0%+0.0pp
TW0.7%+0.2pp
KY0.6%+0.3pp
FR0.6%+0.6pp
GB0.6%+0.2pp
CH0.4%+0.1pp
Top 5: 19.3% · Top 10: 30.6% · Top 25: 46.6%

Winners

TickerPrev $PnLYoY %
FIX$287M+0.94B329.0%
NVDA$795M+0.48B60.9%
VRT$172M+0.42B247.5%
GEV$157M+0.29B186.8%
TPR$254M+0.26B103.3%

Losers

TickerPrev $PnLYoY %
AXON$488M-0.09B-19.3%
ARES$165M-0.04B-23.1%
IOT$135M-0.02B-17.3%
LPLA$272M-0.02B-7.7%
MSFT$688M-0.00B-0.6%

Top buys this quarter · 15

LNG Cheniere Energy, Inc.new+$130M
AIG American International Group, +$108M
AXON Axon Enterprise, Inc.+$452M
WWD Woodward, Inc.+$95M
LTH Life Time Group Holdings, Inc.new+$86M
LLY Eli Lilly and Company+$80M
CELH Celsius Holdings, Inc.+$79M
LPLA LPL Financial Holdings Inc.+$77M
PLXS Plexus Corp.+$77M
PLTR Palantir Technologies Inc.+$76M

Top sells this quarter · 15

LOW Lowe's Companies, Inc.$533M
MASI Masimo Corporation$210M
BAC Bank of America Corporation$134M
RVMD Revolution Medicines, Inc.$125M
SLAB Silicon Laboratories Inc.exit$114M
IBP Installed Building Products, I$37M
HQY HealthEquity, Inc.$104M
MU Micron Technology, Inc.$99M
BURL Burlington Stores, Inc.exit$98M
MTZ MasTec, Inc.$24M

Quarterly history (TTM returns)

PeriodAUM# PosReturn (1yr)SPY (1yr)Alpha (1yr)Flow
2026-03-31$23.59B249+25.90%+17.59%+8.31%-0.09B
2025-12-31$23.93B240+15.24%+17.72%-2.47%-0.25B
2025-09-30$23.76B234+18.64%+17.52%+1.13%-1.48B
2025-06-30$23.71B238+18.94%+14.94%+4.00%-0.29B
2025-03-31$20.44B243-1.94%+8.30%-10.25%-0.27B
2024-12-31$22.86B237+19.51%+24.89%-5.37%-0.31B
2024-09-30$22.11B245+29.50%+36.04%-6.54%+0.39B
2024-06-30$20.35B247+15.01%+24.49%-9.48%+1.92B
2024-03-31$19.05B243+28.87%+29.62%-0.76%+0.15B
2023-12-31$17.12B238+29.82%+26.18%+3.64%+0.49B
2023-09-30$14.64B233+19.75%+21.57%-1.82%-0.23B
2023-06-30$15.69B226+23.82%+19.42%+4.40%+0.39B
2023-03-31$14.11B221-7.90%-7.82%-0.08%-0.30B
2022-12-31$12.95B225-19.11%-18.17%-0.94%-0.24B
2022-09-30$12.59B230+54.39%-15.51%+69.90%+0.14B
2022-06-30$12.70B235-19.35%-16.11%-3.24%+0.12B