WESTFIELD CAPITAL MANAGEMENT CO LP

View all activity View 13F on SEC

Data as of Q4 2025

Institutional investor tracked via SEC 13F filings. Portfolio snapshot as of 2025-12-31.SEC EDGAR Source

Assets Under Management

$24B

Total Positions

241

New This Quarter

Filing Period

2025-12-31

Portfolio Allocation

Top holdings by portfolio weight

NVDA4.62%

ASND4.61%

AAPL3.71%

MSFT3.27%

GOOGL2.84%

FIX2.60%

AMZN2.24%

AXON1.97%

FTAI1.93%

HWM1.90%

Other15.87%

Position Outcomes

Best and worst performing positions by estimated return

Top Winners

CIEN6Q held

Ciena Corp

Avg $61.81 · $5.6M est. P&L

Est. P&L

+285.63%

CRDO4Q held

Credo Technology Group Holding Ltd

Avg $40.51 · $49.1M est. P&L

Est. P&L

+257.74%

FIX9Q held

Comfort Systems USA Inc

Avg $304.00 · $430M est. P&L

Est. P&L

+211.49%

Top Losers

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View plans

Cost basis estimates based on full filing history using quarter-end prices. Actual transaction prices are not disclosed in 13F filings.

Top Holdings(Showing 25 of 241 — sorted by value)

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Activity:

Stock	Shares	Value	Weight	Price Trend	Avg Buy	Est. P&L	Held	Conviction
NVDA NVIDIA Corp	6M	$1.1B	4.6%	—	$116.79	+60.59%	25 qtrs	Decreased 0
ASND ASCENDIS PHARMA A/S	5.2M	$1.1B	4.6%	—	$119.23	+75.57%	29 qtrs	Decreased 0
AAPL Apple Inc	3.3M	$890.2M	3.7%	—	$127.67	+113.68%	29 qtrs	Decreased 0
MSFT Microsoft Corp	1.6M	$784.1M	3.3%	—	$211.16	+130.86%	29 qtrs	Decreased 0
GOOGL Alphabet Inc	2.2M	$681.9M	2.8%	—	$109.55	+186.50%	29 qtrs	Decreased 0
FIX Comfort Systems USA Inc	668,835	$624.2M	2.6%	—	$304.00	+211.49%	9 qtrs	Decreased 0
AMZN Amazon.com Inc	2.3M	$538M	2.2%	—	$137.14	+69.56%	29 qtrs	Decreased 0
AXON Axon Enterprise Inc	831,177	$472.1M	2.0%	—	$346.08	+65.31%	13 qtrs	Increased 56
FTAI FTAI AVIATION LTD	2.4M	$462.7M	1.9%	—	$129.37	+52.80%	7 qtrs	Increased 54
HWM Howmet Aerospace Inc	2.2M	$455M	1.9%	—	$158.83	+30.76%	4 qtrs	Increased 54
META Meta Platforms Inc	655,283	$432.5M	1.8%	—	$305.10	+118.27%	12 qtrs	Decreased 0
AVGO Broadcom Inc	1.1M	$385M	1.6%	—	$176.64	+98.06%	29 qtrs	Decreased 0
VRT Vertiv Holdings Co	2.3M	$369M	1.5%	—	$70.31	+133.74%	10 qtrs	Increased 50
LLY Eli Lilly & Co	277,549	$298.3M	1.2%	—	$739.12	+45.84%	15 qtrs	Increased 49
TPR Tapestry Inc	2.1M	$268.1M	1.1%	—	$52.56	+146.45%	20 qtrs	Decreased 0
RVMD REVOLUTION MEDICINES INC	2.8M	$226.6M	0.9%	—	$44.85	+77.65%	5 qtrs	Increased 49
NOW ServiceNow Inc	1.5M	$226.2M	0.9%	—	$138.98	+10.97%	29 qtrs	Increased 70
LPLA LPL Financial Holdings Inc	625,562	$223.4M	0.9%	—	$213.93	+68.16%	29 qtrs	Increased 47
V Visa Inc	603,926	$211.8M	0.9%	—	$164.94	+113.95%	29 qtrs	Decreased 0
BAC Bank of America Corp	3.8M	$210.3M	0.9%	—	$40.63	+36.06%	13 qtrs	Decreased 0
TSLA Tesla Inc	461,675	$207.6M	0.9%	—	$307.74	+47.67%	17 qtrs	Increased 49
MASI Masimo Corp	1.5M	$198M	0.8%	—	$149.56	-12.36%	11 qtrs	Increased 46
ARES Ares Management Corp	1.2M	$186.1M	0.8%	—	$102.28	+59.58%	18 qtrs	Increased 48
AME AMETEK Inc	900,216	$184.8M	0.8%	—	$151.43	+36.71%	29 qtrs	Increased 69
RKLB ROCKET LAB CORP	2.6M	$180.8M	0.8%	—	$37.80	+86.38%	3 qtrs	Increased 46
Showing 25 of 241 results.PROUpgrade to see all →

Accumulation Streaks

Positions with 2+ consecutive quarters of increases — persistent directional conviction.

Security

BCYCBICYCLE THERAPEUTICS PLC

Q1 2024 → Q4 2025+2.1M shares+$4.8M

DTDynatrace Inc

Q2 2024 → Q4 2025+1.4M shares+$56.2M

WTFCWintrust Financial Corp

Q3 2024 → Q4 2025+351,178 shares+$57.7M

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Data sourced from SEC EDGAR 13F filings. Not financial advice. Full disclaimer