13F Insight
DOSSIER · 13F-HR · Q1 2026

ACK Asset Management LLC

$801M in tracked AUM across 20 positions as of Q1 2026.

AA
CIK 0001510940 · last filed Mar 31, 2026
Total AUM
$801M
as of Q1 2026
Holdings
20
—
positions
Whale Score
67
67
tracked
Activity
—
no data
changes this Q
AI Analysis · Q1 2026

ACK Asset Management LLC filed its latest 13F-HR for Q1 2026. See the latest holdings and position changes below.

Quarter at a glance — Q1 2026

Position-change comparison pending.

No quarter-over-quarter changes available.

Top 10 holdings

By portfolio weight as of Q1 2026.

#HoldingValueSharesWeight
01
MTRN
MTRN
$69M475K8.6%02
WMS
WMS
$53M390K6.7%03
ATS
ATS
$52M1.8M6.5%04
ROG
ROG
$51M475K6.4%05
HLIO
HLIO
$50M780K6.3%06
LFUS
LFUS
$46M135K5.7%07
CNM
CNM
$44M900K5.5%08
NOVT
NOVT
$44M375K5.5%09
SITE
SITE
$44M330K5.5%10
ASTE
ASTE
$42M787K5.3%

Filing history

2026Q1Mar 31
$801M▲ 0.6%
20 positionsView →2025Q4Dec 31
$797M▼ 0.3%
23 positionsView →2025Q3Sep 30
$799M▲ 5.0%
20 positionsView →2025Q2Jun 30
$761M▲ 25.0%
21 positionsLocked2025Q1Mar 31
$609M▼ 18.4%
20 positionsLocked2024Q4Dec 31
$746M▼ 7.8%
22 positionsLocked2024Q3Sep 30
$809M▼ 0.1%
18 positionsLocked2024Q2Jun 30
$810M▼ 5.6%
19 positionsLocked2024Q1Mar 31
$858M▲ 3.2%
20 positionsLocked2023Q4Dec 31
$831M▲ 20.8%
21 positionsLocked2023Q3Sep 30
$688M▼ 14.3%
21 positionsLocked2023Q2Jun 30
$803M▲ 22.6%
23 positionsLocked
Showing 12 of 60