ACK Asset Management LLC 13F holdings, Q4 2025
Holdings as of December 31, 2025 · filings on SEC EDGAR · latest filing →
ACK Asset Management LLC disclosed 23 US equity positions worth $796.8m in its Q4 2025 13F filing. The largest position was MTRN at 7.4% of the reported book, followed by GVA and WMS. Against the Q3 2025 filing, it opened 6 new positions, added to 5 and reduced 6 among the top 23 holdings.
What did ACK Asset Management LLC own in Q4 2025? Top 23 positions
| # | Stock | Sector | Weight | Value | Shares | Δ shares | vs Q3 2025 |
|---|---|---|---|---|---|---|---|
| 1 | MTRN MTRN | Basic Materials | 7.4% | $59.0m | 474,800 | -10% | reduced |
| 2 | GVA GVA | Industrials | 7.2% | $57.7m | 500,000 | -8% | reduced |
| 3 | WMS WMS | Industrials | 7.1% | $56.5m | 390,000 | 0% | held |
| 4 | ATS ATS | 6.4% | $50.8m | 1,846,196 | 0% | held | |
| 5 | CNM CNM | Industrials | 5.9% | $46.8m | 900,000 | 0% | held |
| 6 | ENS ENS | Industrials | 5.6% | $44.7m | 304,324 | -48% | reduced |
| 7 | NOVT NOVT | Technology | 5.6% | $44.6m | 375,000 | – | new |
| 8 | JHX JHX | 5.5% | $43.6m | 2,100,000 | 0% | held | |
| 9 | HLIO HLIO | Industrials | 5.2% | $41.7m | 780,378 | 1% | added |
| 10 | SITE SITE | Industrials | 5.2% | $41.1m | 330,000 | 18% | added |
| 11 | ROG ROG | Technology | 5.0% | $40.0m | 436,707 | – | new |
| 12 | EXP EXP | Basic Materials | 4.3% | $34.1m | 165,000 | 83% | added |
| 13 | ASTE ASTE | Industrials | 4.3% | $34.1m | 786,500 | 12% | added |
| 14 | ATRO ATRO | Industrials | 4.1% | $32.4m | 597,469 | -51% | reduced |
| 15 | AIN AIN | Consumer Cyclical | 3.8% | $30.4m | 600,000 | -21% | reduced |
| 16 | APOG APOG | Industrials | 3.7% | $29.6m | 813,000 | 15% | added |
| 17 | DXPE DXPE | Industrials | 3.3% | $26.3m | 240,000 | – | new |
| 18 | MBC MBC | Consumer Cyclical | 3.2% | $25.4m | 2,300,000 | 0% | held |
| 19 | CDNL CDNL | 2.6% | $20.4m | 844,591 | – | new | |
| 20 | CLFD CLFD | Technology | 2.3% | $18.2m | 625,200 | 0% | held |
| 21 | ERII ERII | Industrials | 1.1% | $9.1m | 677,251 | – | new |
| 22 | AERO-SWX | 0.7% | $5.5m | 154,851 | – | new | |
| 23 | CTOS CTOS | 0.6% | $4.6m | 800,136 | -58% | reduced |
Weights are shares of the reported long US equity book (options excluded). Values are as filed, normalised to whole dollars. Share changes compare against the immediately preceding filing only.