DOSSIER · 13F-HR · Q2 2026

FRONTIER CAPITAL MANAGEMENT CO LLC

$10.7B in tracked AUM across 300 positions as of Q2 2026.

FC
CIK 0000351173 · last filed Jun 30, 2026
Total AUM
$10.7B
as of Q2 2026
Holdings
300
positions
Whale Score
59
59
tracked
Activity
no data
changes this Q
AI Analysis · Q2 2026
Comprehensive Analysis of SEC 13F Filing: Frontier Capital Management Co LLC
1. Portfolio Overview

Frontier Capital Management Co LLC reported a significant contraction in portfolio value for the quarter ended September 30, 2025. The total assets under management (AUM) decreased by 42.4%, dropping from $10.80 billion to $6.23 billion. This substantial reduction is likely driven by a combination of realized losses from asset liquidations, market depreciation, and active capital return to i...

The portfolio remains highly diversified, consisting of 163 holdings. Despite the large number of positions, the firm employs a focused approach where capital is allocated efficiently across specific themes. The top 10 holdings account for approximately 23.8% of the total portfolio value, indicating a preference for high-conviction positions while maintaining a long tail of smaller allocations to capture broader market opportunities or specific situational plays. The management firm demonstrated high velocity this quarter, with zero positions remaining unchanged; they executed 28 new buys, 28 complete exits, and adjusted 22 existing positions.

2. Key Holdings
Analysis generated by 13F Insight from SEC Form 13F filing data · Q2 2026. Methodology

Quarter at a glance — Q2 2026

Position-change comparison pending.

No quarter-over-quarter changes available.

Top 10 holdings

By portfolio weight as of Q2 2026.

#HoldingValueSharesWeight
01
G3730V105
FTAI AVIATION LTD
$320M1.2M3.0%
02
GVA
GRANITE CONSTR INC
$177M1.1M1.6%
03
ALK
ALASKA AIR GROUP INC
$177M3.4M1.6%
04
AAOI
APPLIED OPTOELECTRONICS INC
$145M975K1.3%
05
AKAM
AKAMAI TECHNOLOGIES INC
$134M1.1M1.3%
06
ASH
ASHLAND INC
$132M2.0M1.2%
07
LSCC
LATTICE SEMICONDUCTOR CORP
$126M822K1.2%
08
BPOP
POPULAR INC
$119M725K1.1%
09
MDB
MONGODB INC
$112M334K1.0%
10
UTHR
UNITED THERAPEUTICS CORP DEL
$112M207K1.0%

Filing history

2026Q2Jun 30
$10.7B 10.3%
300 positionsView →
2026Q1Mar 31
$9.7B 3.2%
291 positionsView →
2025Q4Dec 31
$9.4B 51.3%
295 positionsView →
2025Q3Sep 30
$6.2B 42.4%
163 positionsView →
2025Q2Jun 30
$10.8B 18.1%
294 positionsLocked
2025Q1Mar 31
$9.1B 13.1%
283 positionsLocked
2024Q4Dec 31
$10.5B 0.9%
285 positionsLocked
2024Q3Sep 30
$10.6B 5.2%
281 positionsLocked
2024Q2Jun 30
$10.1B 5.6%
279 positionsLocked
2024Q1Mar 31
$10.7B 8.1%
269 positionsLocked
2023Q4Dec 31
$9.9B 8.8%
263 positionsLocked
2023Q3Sep 30
$9.1B 12.8%
267 positionsLocked
Showing 12 of 84