ACK Asset Management LLC

In its 13F for Q3 2024 (holdings as of September 30, 2024, filed November 13, 2024), ACK Asset Management LLC reported 18 stock positions worth $809.2 million. Its top holding was Dycom Industries (DY) at 13.0% of the portfolio, followed by Mastec (MTZ, 11.7%) and Enersys (ENS, 9.0%). Compared with Q2 2024, it opened 4 new positions, sold out of 5, added to 4 and reduced 1. The biggest buy was a new position in Primoris Services (PRIM) and the biggest sale an exit from Core & Main Class A (CNM).

Most Recent 13F
Q2 2026
Location
GREENWICH, CT
CIK
0001510940
Portfolio Value
$809.2M (Q3 2024)
SEC Filing
0000899140-24-001197 ↗ filed Nov 13, 2024

Holdings Value

0$200.0M$400.0M$600.0M$800.0M$1.0B Q1 2024: $858.3M Q1 2024 Q2 2024: $810.3M Q2 2024 Q3 2024: $809.2M $809.2M Q3 2024 Q4 2024: $746.4M Q4 2024 Q1 2025: $609.0M Q1 2025 Q2 2025: $761.4M Q2 2025 Q3 2025: $799.1M Q3 2025 Q4 2025: $796.8M Q4 2025 Q1 2026: $801.1M Q1 2026 Q2 2026: $856.3M Q2 2026

Holdings 18 stocks · $809.2M
DY Dycom Industries Inc. 13.04% 535,500 $105.5M No change
MTZ Mastec Inc. 11.75% 772,300 $95.1M No change
ENS Enersys 9.02% 715,000 $73.0M No change
ROG Rogers Corp. 8.24% 590,000 $66.7M No change
ATS Ats Corp. 8.10% 2,255,889 $65.5M Add +12.8%
GVA Granite Construction Inc. 8.08% 825,000 $65.4M No change
MTRN Materion Corp. 6.99% 505,500 $56.5M No change
ESI Element Solutions Inc. 6.68% 1,990,000 $54.0M Add +32.7%
MIR Mirion Technologies Inc. 5.81% 4,246,300 $47.0M Add +28.8%
ATRO Astronics Corp. 4.96% 2,060,000 $40.1M No change
NEOG Neogen Corp. 3.45% 1,659,400 $27.9M No change
CECO Ceco Environmental Corp. 3.42% 981,200 $27.7M Add +19.5%
CLFD Clearfield Inc. 3.35% 695,000 $27.1M No change
PRIM Primoris Services Corp. 2.80% 390,000 $22.7M New
CALX Calix Inc. 1.54% 321,124 $12.5M New
MBC Masterbrand Inc. 1.49% 650,000 $12.1M New
MTRX Matrix Service Co. 1.14% 801,000 $9.2M New
LUNA Luna Innovations Inc. 0.15% 525,000 $1.2M Reduce -32.6%

Portfolio Sells Q2 2024 → Q3 2024
CNM Core & Main Inc. Class A Sold out 0.00% −8.17
ARRY Array Technologies Inc. Sold out 0.00% −5.42
FIP Ftai Infrastructure Inc. Sold out 0.00% −1.09
THRY Thryv Holdings Inc. Sold out 0.00% −0.54
MDA Mda Space Ltd. Sold out 0.00% −0.26
LUNA Luna Innovations Inc. Reduce -32.6% 0.15% −0.16

Portfolio Buys Q2 2024 → Q3 2024
PRIM Primoris Services Corp. New 2.80% +2.80
ESI Element Solutions Inc. Add +32.7% 6.68% +1.66
CALX Calix Inc. New 1.54% +1.54
MBC Masterbrand Inc. New 1.49% +1.49
MIR Mirion Technologies Inc. Add +28.8% 5.81% +1.44
MTRX Matrix Service Co. New 1.14% +1.14
CECO Ceco Environmental Corp. Add +19.5% 3.42% +0.50
ATS Ats Corp. Add +12.8% 8.10% +0.12

All Filings

QuarterPositions13F Reported ValueTop Holdings
Q2 2026 21$856.3MWMS, HLIO, LFUS, JHX, GTX
Q1 2026 20$801.1MMTRN, WMS, ATS, ROG, HLIO
Q4 2025 23$796.8MMTRN, GVA, WMS, ATS, CNM
Q3 2025 20$799.1MENS, MTRN, GVA, ATRO, WMS
Q2 2025 21$761.4MATRO, ATS, DY, GVA, ENS
Q1 2025 20$609.0MDY, ENS, MTZ, ATS, ATRO
Q4 2024 22$746.4MDY, MTZ, ATS, ENS, ROG
Q3 2024 18$809.2MDY, MTZ, ENS, ROG, ATS
Q2 2024 19$810.3MDY, MTZ, ENS, ROG, CNM
Q1 2024 20$858.3MCNM, DY, ATKR, MTZ, ENS