FRONTIER CAPITAL MANAGEMENT CO LLC

Boston, MA · CIK 351173 · 13F filing filed 2026-08-14

SEC-registered investment adviser since 1981 · limited liability company

Assets managed$9.6bn
Staff38 · 19 in investment roles
Main clients (by assets)State and local governments 41%, Mutual funds and ETFs 26%, Pension plans 17%
Private funds5 · $445.6m gross assets
Websitefrontiercap.com
Form ADV · 2026-09-01SEC adviser record

Legal entityFRONTIER CAPITAL MANAGEMENT COMPANY, LLC (US)

$10.7bn reported value +10.3% vs Q1 2026

300positions

14.5%in top 10

33 new 96 added 171 reduced 24 sold out vs Q1 2026

Also in the report of:

American Trust

Shares in two reports are counted once in each security's totals.

Holdings, Q2 2026

The small lines show how much was held over the last 4 quarters (adjusted for stock splits).

#	Security	Ticker	Shares	Value	% of portfolio	Change	Shares change
1	FTAI AVIATION LTD SHS FTAI	FTAI	1,183,492	$320.2m2.98%	2.98%	Added +121.3k	+121,282 11.4%
2	GRANITE CONSTR INC COM GVA	GVA	1,118,881	$176.9m1.65%	1.65%	Reduced -68.9k	-68,855 -5.8%
3	ALASKA AIR GROUP INC COM ALK	ALK	3,384,643	$176.7m1.65%	1.65%	Added +11.1k	+11,056 0.3%
4	APPLIED OPTOELECTRONICS INC COM AAOI	AAOI	975,318	$144.5m1.35%	1.35%	Added +691.2k	+691,172 243.2%
5	AKAMAI TECHNOLOGIES INC COM AKAM	AKAM	1,136,573	$134.4m1.25%	1.25%	Added +100.0k	+100,004 9.7%
6	ASHLAND INC COM ASH	ASH	1,999,908	$131.8m1.23%	1.23%	Added +87.2k	+87,219 4.6%
7	LATTICE SEMICONDUCTOR CORP COM LSCC	LSCC	821,848	$125.7m1.17%	1.17%	Added +216.5k	+216,530 35.8%
8	POPULAR INC COM NEW BPOP	BPOP	725,227	$119.1m1.11%	1.11%	Reduced -75.7k	-75,703 -9.4%
9	MONGODB INC CL A MDB	MDB	334,098	$112.2m1.05%	1.05%	Added +119.8k	+119,782 55.9%
10	UNITED THERAPEUTICS CORP DEL COM UTHR	UTHR	206,808	$112.1m1.04%	1.04%	Reduced -45.9k	-45,894 -18.2%
11	KNIGHT-SWIFT TRANSN HLDGS IN CL A KNX	KNX	1,410,955	$109.9m1.02%	1.02%	Reduced -675.6k	-675,589 -32.4%
12	EAGLE MATLS INC COM EXP	EXP	458,621	$103.2m0.96%	0.96%	Reduced -152.0k	-152,033 -24.9%
13	STRIDE INC COM LRN	LRN	1,191,710	$102.8m0.96%	0.96%	Reduced -357.6k	-357,581 -23.1%
14	XPO INC COM XPO	XPO	499,601	$102.6m0.96%	0.96%	Reduced -152.5k	-152,472 -23.4%
15	BRIDGEBIO PHARMA INC COM BBIO	BBIO	1,373,057	$102.3m0.95%	0.95%	Added +415.1k	+415,068 43.3%
16	LIBERTY ENERGY INC COM CL A LBRT	LBRT	3,720,666	$97.4m0.91%	0.91%	Added +1.2m	+1,226,444 49.2%
17	SANMINA CORPORATION COM SANM	SANM	378,111	$95.7m0.89%	0.89%	Reduced -259.3k	-259,277 -40.7%
18	ULTRA CLEAN HLDGS INC COM UCTT	UCTT	667,532	$95.2m0.89%	0.89%	Reduced -1.1m	-1,119,919 -62.6%
19	ULTRAGENYX PHARMACEUTICAL IN COM RARE	RARE	2,847,936	$95.1m0.89%	0.89%	Added +656.8k	+656,754 30.0%
20	INSULET CORP COM PODD	PODD	622,506	$94.8m0.88%	0.88%	Added +450.0k	+449,993 260.9%
21	MODINE MFG CO COM MOD	MOD	343,868	$91.8m0.86%	0.86%	Added +139.8k	+139,829 68.5%
22	FLOWSERVE CORP COM FLS	FLS	1,233,291	$91.5m0.85%	0.85%	Added +770.8k	+770,843 166.7%
23	KIRBY CORP COM KEX	KEX	666,554	$90.6m0.84%	0.84%	Added +22.2k	+22,225 3.5%
24	ALLEGIANT TRAVEL CO COM ALGT	ALGT	765,347	$90.0m0.84%	0.84%	Added +164.1k	+164,132 27.3%
25	PURE STORAGE INC CL A P	P	1,120,040	$88.2m0.82%	0.82%	Added +175.5k	+175,518 18.6%
26	AMENTUM HOLDINGS INC COM AMTM	AMTM	4,143,971	$85.7m0.80%	0.80%	Reduced -786.2k	-786,239 -15.9%
27	KYMERA THERAPEUTICS INC COM KYMR	KYMR	740,866	$85.0m0.79%	0.79%	Reduced -19.0k	-18,982 -2.5%
28	INSMED INC COM PAR $.01 INSM	INSM	795,242	$84.8m0.79%	0.79%	Added +325.7k	+325,681 69.4%
29	ATI INC COM ATI	ATI	419,968	$82.8m0.77%	0.77%	Reduced -274.5k	-274,454 -39.5%
30	RENASANT CORP COM RNST	RNST	1,778,953	$75.7m0.71%	0.71%	Added +76.2k	+76,240 4.5%
31	ASTERA LABS INC COM ALAB	ALAB	154,601	$74.7m0.70%	0.70%	Reduced -533.6k	-533,612 -77.5%
32	ROYAL CARIBBEAN GROUP COM RCL	RCL	233,963	$74.3m0.69%	0.69%	Reduced -4.3k	-4,336 -1.8%
33	PALVELLA THERAPEUTICS INC NE COM PVLA	PVLA	478,833	$73.2m0.68%	0.68%	Added +104.8k	+104,798 28.0%
34	DYNATRACE INC COM NEW DT	DT	1,635,587	$71.8m0.67%	0.67%	New
35	INDIE SEMICONDUCTOR INC CLASS A COM INDI	INDI	15,914,169	$71.5m0.67%	0.67%	Reduced -3.3m	-3,331,919 -17.3%
36	AGREE RLTY CORP COM ADC	ADC	943,005	$71.4m0.67%	0.67%	Reduced -158.4k	-158,381 -14.4%
37	INTUITIVE MACHINES INC CLASS A COM LUNR	LUNR	3,173,434	$67.9m0.63%	0.63%	Reduced -340.4k	-340,365 -9.7%
38	JAZZ PHARMACEUTICALS PLC SHS USD JAZZ	JAZZ	277,279	$66.8m0.62%	0.62%	Reduced -240.0k	-240,005 -46.4%
39	SAIA INC COM SAIA	SAIA	151,477	$63.8m0.59%	0.59%	Reduced -31.0k	-31,015 -17.0%
40	ENTEGRIS INC COM ENTG	ENTG	351,950	$63.3m0.59%	0.59%	Reduced -402.8k	-402,756 -53.4%
41	FIRST BANCORP P R COM NEW FBP	FBP	2,422,265	$63.1m0.59%	0.59%	Reduced -501.5k	-501,473 -17.1%
42	CIRCLE INTERNET GROUP INC COM CL A CRCL	CRCL	1,004,783	$62.9m0.59%	0.59%	Reduced -543.4k	-543,367 -35.1%
43	HUBBELL INC COM HUBB	HUBB	119,997	$62.8m0.59%	0.59%	Added +94.9k	+94,929 378.7%
44	AXSOME THERAPEUTICS INC COM AXSM	AXSM	254,280	$62.2m0.58%	0.58%	Added +51.2k	+51,214 25.2%
45	FLEX LTD ORD FLEX	FLEX	382,135	$61.9m0.58%	0.58%	Added +20.5k	+20,549 5.7%
46	WINTRUST FINL CORP COM WTFC	WTFC	384,593	$61.8m0.58%	0.58%	Reduced -77.4k	-77,419 -16.8%
47	TIDEWATER INC NEW COM TDW	TDW	894,796	$59.6m0.56%	0.56%	Reduced -178.0k	-177,997 -16.6%
48	ATMUS FILTRATION TECHNOLOGIE COM ATMU	ATMU	1,157,930	$59.0m0.55%	0.55%	Added +415.7k	+415,709 56.0%
49	JABIL INC COM JBL	JBL	152,187	$58.7m0.55%	0.55%	Reduced -12.6k	-12,640 -7.7%
50	BUILDERS FIRSTSOURCE INC COM BLDR	BLDR	651,389	$58.3m0.54%	0.54%	Reduced -209.1k	-209,105 -24.3%
51	SNOWFLAKE INC CL A SNOW	SNOW	226,439	$57.6m0.54%	0.54%	Added +155.1k	+155,130 217.6%
52	TREVI THERAPEUTICS INC COM TRVI	TRVI	3,070,740	$57.3m0.53%	0.53%	Added +1.1m	+1,076,448 54.0%
53	GENIUS SPORTS LIMITED SHARES CL A GENI	GENI	9,432,864	$57.2m0.53%	0.53%	Added +4.5m	+4,464,966 89.9%
54	THE BALDWIN INSURANCE GRP IN COM CL A BWIN	BWIN	2,097,658	$55.8m0.52%	0.52%	Added +995.2k	+995,206 90.3%
55	VERA THERAPEUTICS INC CL A VERA	VERA	1,295,405	$55.6m0.52%	0.52%	Added +743.9k	+743,912 134.9%
56	UROGEN PHARMA LTD COM URGN	URGN	1,508,547	$55.5m0.52%	0.52%	Added +194.4k	+194,435 14.8%
57	MKS INC. COM MKSI	MKSI	120,625	$53.7m0.50%	0.50%	Reduced -40.6k	-40,625 -25.2%
58	GARRETT MOTION INC COM GTX	GTX	1,466,821	$53.1m0.50%	0.50%	Reduced -1.2m	-1,208,312 -45.2%
59	ELANCO ANIMAL HEALTH INC COM ELAN	ELAN	2,138,550	$52.6m0.49%	0.49%	Reduced -224.0k	-223,976 -9.5%
60	EASTERN BANKSHARES INC COM EBC	EBC	2,332,022	$51.9m0.48%	0.48%	Reduced -508.3k	-508,271 -17.9%
61	FIRST AMERN FINL CORP COM FAF	FAF	749,097	$51.4m0.48%	0.48%	Reduced -131.7k	-131,707 -14.9%
62	API GROUP CORP COM STK APG	APG	1,203,831	$51.0m0.48%	0.48%	Added +657.0k	+657,024 120.2%
63	STAG INDL INC COM STAG	STAG	1,331,842	$50.7m0.47%	0.47%	Reduced -169.7k	-169,725 -11.3%
64	WEATHERFORD INTL PLC ORD SHS WFRD	WFRD	617,390	$50.3m0.47%	0.47%	Reduced -108.1k	-108,107 -14.9%
65	AAR CORP COM AIR	AIR	350,441	$50.1m0.47%	0.47%	Reduced -76.7k	-76,746 -18.0%
66	CARPENTER TECHNOLOGY CORP COM CRS	CRS	80,488	$49.6m0.46%	0.46%	Reduced -18.6k	-18,646 -18.8%
67	PERDOCEO ED CORP COM PRDO	PRDO	1,547,631	$49.5m0.46%	0.46%	Reduced -299.4k	-299,355 -16.2%
68	ACADIA HEALTHCARE COMPANY IN COM ACHC	ACHC	1,672,857	$49.4m0.46%	0.46%	Added +1.1m	+1,097,614 190.8%
69	COGNEX CORP COM CGNX	CGNX	669,588	$48.5m0.45%	0.45%	Reduced -24.3k	-24,311 -3.5%
70	FIRST INDL RLTY TR INC COM FR	FR	788,792	$48.4m0.45%	0.45%	Reduced -157.6k	-157,573 -16.6%
71	DATADOG INC CL A COM DDOG	DDOG	182,164	$47.4m0.44%	0.44%	Added +88.8k	+88,765 95.0%
72	NATERA INC COM NTRA	NTRA	173,547	$47.1m0.44%	0.44%	Reduced -120.8k	-120,800 -41.0%
73	PRIMORIS SVCS CORP COM PRIM	PRIM	468,762	$46.5m0.43%	0.43%	New
74	ANTERO RESOURCES CORP COM AR	AR	1,318,103	$46.3m0.43%	0.43%	Reduced -31.1k	-31,134 -2.3%
75	FAIR ISAAC CORP COM FICO	FICO	38,278	$45.7m0.43%	0.43%	Added +6.8k	+6,807 21.6%
76	MONOLITHIC PWR SYS INC COM MPWR	MPWR	32,723	$45.2m0.42%	0.42%	Reduced -47.0k	-46,976 -58.9%
77	TRIUMPH FINANCIAL INC COM TFIN	TFIN	584,333	$44.6m0.42%	0.42%	Reduced -60.4k	-60,444 -9.4%
78	DARLING INGREDIENTS INC COM DAR	DAR	793,866	$43.4m0.40%	0.40%	Reduced -1.7m	-1,661,802 -67.7%
79	STANDARDAERO INC COM SARO	SARO	1,449,333	$43.3m0.40%	0.40%	New
80	VOYAGER TECHNOLOGIES INC COM CL A VOYG	VOYG	1,343,054	$43.3m0.40%	0.40%	Added +115.9k	+115,867 9.4%
81	TD SYNNEX CORPORATION COM SNX	SNX	161,933	$43.3m0.40%	0.40%	Reduced -131.3k	-131,349 -44.8%
82	CHEMED CORP NEW COM CHE	CHE	90,567	$42.2m0.39%	0.39%	Added +27.8k	+27,841 44.4%
83	MDU RES GROUP INC COM MDU	MDU	1,987,666	$42.2m0.39%	0.39%	Reduced -518.9k	-518,883 -20.7%
84	REGAL REXNORD CORPORATION COM RRX	RRX	176,675	$42.1m0.39%	0.39%	Reduced -41.2k	-41,235 -18.9%
85	PAGAYA TECHNOLOGIES LTD CL A NEW PGY	PGY	2,296,417	$41.9m0.39%	0.39%	Added +2.1m	+2,099,721 1067.5%
86	ACV AUCTIONS INC COM CL A COM CL A		5,813,660	$41.8m0.39%	0.39%	Added +1.9m	+1,884,339 48.0%
87	KBR INC COM KBR	KBR	1,206,062	$41.6m0.39%	0.39%	Reduced -228.0k	-228,033 -15.9%
88	RYERSON HLDG CORP COM RYZ	RYZ	1,683,408	$41.4m0.39%	0.39%	Added +166.3k	+166,346 11.0%
89	ERO COPPER CORP COM ERO	ERO	1,540,063	$41.2m0.38%	0.38%	Added +289.1k	+289,116 23.1%
90	INSIGHT ENTERPRISES INC COM NSIT	NSIT	337,686	$41.1m0.38%	0.38%	Reduced -167.6k	-167,625 -33.2%
91	WSFS FINL CORP COM WSFS	WSFS	535,179	$41.1m0.38%	0.38%	Reduced -140.3k	-140,317 -20.8%
92	TERADYNE INC COM TER	TER	84,563	$40.9m0.38%	0.38%	Reduced -98.6k	-98,641 -53.8%
93	GULFPORT ENERGY CORP COMMON SHARES GPOR	GPOR	240,790	$40.9m0.38%	0.38%	Added +18.8k	+18,841 8.5%
94	SEACOAST BKG CORP FLA COM NEW SBCF	SBCF	1,227,771	$40.8m0.38%	0.38%	Added +228.5k	+228,525 22.9%
95	CREDO TECHNOLOGY GROUP HOLDI ORDINARY SHARES CRDO	CRDO	149,509	$40.7m0.38%	0.38%	Added +37.3k	+37,274 33.2%
96	CLOUDFLARE INC CL A COM NET	NET	165,415	$40.6m0.38%	0.38%	Added +8.1k	+8,116 5.2%
97	APOGEE THERAPEUTICS INC COM COM		303,739	$40.3m0.38%	0.38%	Reduced -760.7k	-760,744 -71.5%
98	LEMONADE INC COM LMND	LMND	609,820	$39.7m0.37%	0.37%	Reduced -62.6k	-62,563 -9.3%
99	INDEPENDENCE RLTY TR INC COM IRT	IRT	2,376,740	$39.7m0.37%	0.37%	Reduced -493.0k	-492,980 -17.2%
100	QUANTA SVCS INC COM PWR	PWR	54,069	$38.9m0.36%	0.36%	Reduced -2.8k	-2,828 -5.0%

Sold out since Q1 2026

Security	Ticker	Shares held before	Value then
MARVELL TECHNOLOGY INC MRVL	MRVL	540,979	$53.6m541.0k shares
NUVALENT INC		395,546	$40.5m395.5k shares
DIODES INC DIOD	DIOD	592,499	$40.4m592.5k shares
QUIDELORTHO CORP QDEL	QDEL	1,752,613	$28.8m1.8m shares
DOMINOS PIZZA INC DPZ	DPZ	62,733	$22.5m62.7k shares
EVERUS CONSTR GROUP ECG	ECG	143,499	$16.9m143.5k shares
ARISTA NETWORKS INC ANET	ANET	136,947	$16.8m136.9k shares
TRACTOR SUPPLY CO TSCO	TSCO	362,574	$16.4m362.6k shares
AMPHENOL CORP APH	APH	124,757	$15.8m124.8k shares
RESMED INC RMD	RMD	65,224	$14.6m65.2k shares
CAESARS ENTERTAINMENT INC NE CZR	CZR	503,396	$13.3m503.4k shares
KLA CORP KLAC	KLAC	80,990	$11.9m81.0k shares
LULULEMON ATHLETICA INC LULU	LULU	77,472	$11.9m77.5k shares
SUN CTRY AIRLS HLDGS INC SNCY	SNCY	584,311	$9.7m584.3k shares
NASDAQ INC NDAQ	NDAQ	106,895	$9.1m106.9k shares
THE TRADE DESK INC TTD	TTD	321,192	$7.3m321.2k shares
GRID DYNAMICS HLDGS INC GDYN	GDYN	1,129,076	$6.4m1.1m shares
ROSS STORES INC ROST	ROST	26,507	$5.7m26.5k shares
VIRIDIAN THERAPEUTICS INC VRDN	VRDN	158,371	$3.1m158.4k shares
SHOALS TECHNOLOGIES GROUP IN SHLS	SHLS	97,840	$643.8k97.8k shares
PARSONS CORP DEL PSN	PSN	11,310	$612.7k11.3k shares
COTERRA ENERGY INC CTRA	CTRA	12,509	$439.6k12.5k shares
ALIGNMENT HEALTHCARE INC ALHC	ALHC	18,820	$331.6k18.8k shares
LKQ CORP LKQ	LKQ	8,916	$261.9k8.9k shares

Stakes above 5%

Companies where this manager has reported owning more than 5% of a class of shares, on Schedule 13D (may seek influence) or 13G (passive): its latest filing for each, from 19 Dec 2024 on.

Company	Ticker	Stake	Change	Schedule	Last filed
INDIE SEMICONDUCTOR INC INDI · 13G · filed 2026-08-14	INDI	7.5%≈ $71.5m		13G	2026-08-14
FTAI INFRASTRUCTURE INC FIP · 13G · filed 2026-02-17	FIP	5.7%≈ $30.5m	new	13G	2026-02-17