FRONTIER CAPITAL MANAGEMENT CO LLC

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

$9.4B

Total Positions

295

New This Quarter

Filing Period

2025-12-31

Portfolio Allocation

Top holdings by portfolio weight

FTAI2.71%

AMTM1.78%

GVA1.54%

ATI1.49%

MDB1.35%

ALAB1.30%

NTRA1.27%

BPOP1.26%

ALK1.22%

EXP1.20%

Other14.21%

Position Outcomes

Best and worst performing positions by estimated return

Top Winners

CRS28Q held

Carpenter Technology Corp

Avg $36.26 · $41.9M est. P&L

Est. P&L

+778.25%

JBL28Q held

Jabil Inc

Avg $27.75 · $32.9M est. P&L

Est. P&L

+734.52%

FLEX28Q held

Flex Ltd

Avg $7.64 · $19.2M est. P&L

Est. P&L

+707.09%

Top Losers

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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 295 — sorted by value)

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Activity:

Stock	Shares	Value	Weight	Price Trend	Avg Buy	Est. P&L	Held	Conviction
FTAI FTAI AVIATION LTD	1.3M	$255.2M	2.7%	—	$37.76	+423.53%	13 qtrs	Decreased 0
AMTM AMENTUM HOLDINGS INC	5.8M	$167.4M	1.8%	—	$20.85	+40.52%	4 qtrs	Increased 53
GVA GRANITE CONSTR INC	1.3M	$145.1M	1.5%	—	$49.00	+138.02%	28 qtrs	Decreased 0
ATI ATI Inc	1.2M	$140.9M	1.5%	—	$29.87	+288.88%	28 qtrs	Decreased 0
MDB MongoDB Inc	302,093	$126.8M	1.3%	—	$285.23	+47.68%	27 qtrs	Increased 51
ALAB Astera Labs Inc	735,341	$122.3M	1.3%	—	$170.64	+0.12%	4 qtrs	Increased 77
NTRA Natera Inc	521,750	$119.5M	1.3%	—	$110.76	+107.64%	27 qtrs	Increased 63
BPOP POPULAR INC	954,230	$118.8M	1.3%	—	$70.54	+78.57%	28 qtrs	Decreased 0
ALK Alaska Air Group Inc	2.3M	$114.7M	1.2%	—	$48.28	+3.82%	28 qtrs	Increased 59
EXP Eagle Materials Inc	545,349	$112.7M	1.2%	—	$178.97	+17.43%	28 qtrs	Decreased 0
TER Teradyne Inc	571,240	$110.6M	1.2%	—	$116.93	+68.13%	5 qtrs	Decreased 0
KNX Knight-Swift Transportation Holdings Inc	2M	$102.2M	1.1%	—	$49.91	+5.38%	28 qtrs	Increased 76
DAR DARLING INGREDIENTS INC	2.7M	$97.9M	1.0%	—	$38.42	-4.92%	11 qtrs	Decreased 0
XPO XPO Inc	720,353	$97.9M	1.0%	—	$52.77	+160.93%	19 qtrs	Decreased 0
SANM Sanmina Corp	638,741	$95.9M	1.0%	—	$69.32	+119.32%	9 qtrs	Decreased 0
CRCL CIRCLE INTERNET GROUP INC C	1.1M	$89.6M	1.0%	—	$79.89	0.00%	1 qtr	New 58
UCTT ULTRA CLEAN HLDGS INC	3.5M	$88.9M	0.9%	—	$30.76	-16.23%	13 qtrs	Increased 48
UTHR United Therapeutics Corp	181,177	$88.3M	0.9%	—	$337.12	+47.18%	24 qtrs	Increased 44
ENTG Entegris Inc	1M	$88.3M	0.9%	—	$91.37	-5.20%	6 qtrs	Decreased 0
MKSI MKS Inc	550,735	$88M	0.9%	—	$104.22	+55.27%	28 qtrs	Decreased 0
MAT Mattel Inc	4.2M	$83.6M	0.9%	—	$16.13	+23.95%	25 qtrs	Decreased 0
ASH Ashland Inc	1.4M	$83.6M	0.9%	—	$55.62	+6.35%	2 qtrs	Increased 68
MPWR Monolithic Power Systems Inc	84,118	$76.2M	0.8%	—	$566.76	+62.74%	28 qtrs	Decreased 0
WTFC Wintrust Financial Corp	543,048	$75.9M	0.8%	—	$70.54	+99.30%	25 qtrs	Increased 42
LCII LCI Industries	595,842	$72.3M	0.8%	—	$88.04	+39.58%	28 qtrs	Decreased 0
Showing 25 of 295 results.PROUpgrade to see all →

Accumulation Streaks

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

Security

PSTGPure Storage Inc

Q4 2024 → Q4 2025+382,058 shares+$34M

FIPFTAI INFRASTRUCTURE INC

Q1 2025 → Q4 2025+6.2M shares+$27.5M

HQYHealthEquity Inc

Q1 2025 → Q4 2025+83,886 shares+$7.5M

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