# ACK Asset Management LLC

> Institutional holdings reported to the SEC as of Q2 2026 on Form 13F. CIK 1510940. Source: https://holderbook.com/funds/1510940-ack-asset-management-llc/

- Reported value: $856.3M
- Positions: 21
- Weight of the ten largest: 60.2%
- Filed: 2026-08-13

A 13F reports long US equity positions only. Short positions, bonds, foreign listings, private holdings and cash are not visible, so this is not the manager's whole book.

## Holdings

| Security | Ticker | Value | Shares | Weight | Quarters held |
|---|---|---|---|---|---|
| ADVANCED DRAIN SYS INC DEL | [WMS](https://holderbook.com/stocks/WMS/) | $61.2M | 390,000 | 7.1% | 5 |
| HELIOS TECHNOLOGIES INC | [HLIO](https://holderbook.com/stocks/HLIO/) | $60.8M | 681,000 | 7.1% | 4 |
| LITTELFUSE INC | [LFUS](https://holderbook.com/stocks/LFUS/) | $56.9M | 125,000 | 6.6% | 2 |
| JAMES HARDIE INDS PLC | [JHX](https://holderbook.com/stocks/JHX/) | $55.0M | 2,100,000 | 6.4% | 4 |
| GARRETT MOTION INC | [GTX](https://holderbook.com/stocks/GTX/) | $54.3M | 1,500,000 | 6.3% | 1 |
| CORE & MAIN INC | [CNM](https://holderbook.com/stocks/CNM/) | $52.6M | 1,090,000 | 6.1% | 4 |
| EAGLE MATLS INC | [EXP](https://holderbook.com/stocks/EXP/) | $49.5M | 220,000 | 5.8% | 4 |
| ATS CORPORATION | [ATS](https://holderbook.com/stocks/ATS/) | $43.2M | 1,500,000 | 5.0% | 15 |
| ASTEC INDS INC | [ASTE](https://holderbook.com/stocks/ASTE/) | $42.2M | 690,276 | 4.9% | 4 |
| MATERION CORP | [MTRN](https://holderbook.com/stocks/MTRN/) | $40.1M | 135,000 | 4.7% | 26 |
| BORGWARNER INC | [BWA](https://holderbook.com/stocks/BWA/) | $39.8M | 600,000 | 4.7% | 1 |
| DNOW INC | [DNOW](https://holderbook.com/stocks/DNOW/) | $38.9M | 3,000,000 | 4.5% | 1 |
| MASTERBRAND INC | [MBC](https://holderbook.com/stocks/MBC/) | $38.1M | 3,700,000 | 4.4% | 4 |
| SITEONE LANDSCAPE SUPPLY INC | [SITE](https://holderbook.com/stocks/SITE/) | $37.8M | 330,000 | 4.4% | 6 |
| LATHAM GROUP INC | [SWIM](https://holderbook.com/stocks/SWIM/) | $36.6M | 5,660,000 | 4.3% | 2 |
| CLEARFIELD INC | [CLFD](https://holderbook.com/stocks/CLFD/) | $32.2M | 810,200 | 3.8% | 11 |
| SENSATA TECHNOLOGIES HLDG PL | [ST](https://holderbook.com/stocks/ST/) | $28.6M | 600,000 | 3.3% | 1 |
| AERO-SWX | - | $28.5M | 1,082,500 | 3.3% | 3 |
| SHOALS TECHNOLOGIES GROUP IN | [SHLS](https://holderbook.com/stocks/SHLS/) | $22.3M | 2,255,000 | 2.6% | 1 |
| EQUIPMENTSHARE COM INC | [EQPT](https://holderbook.com/stocks/EQPT/) | $20.9M | 1,064,830 | 2.4% | 1 |
| METHODE ELECTRS INC | [MEI](https://holderbook.com/stocks/MEI/) | $16.6M | 877,500 | 1.9% | 1 |

## What the disclosed book did

Not the fund's return. This is the change in value of the positions disclosed on Form 13F, had they been left untouched, against SPY over the same quarter ends.

| Quarter | Book | Market | Difference | Priced |
|---|---|---|---|---|
| Q2 2026 | +35.8% | +14.8% | +20.9% | 97% |
| Q1 2026 | +6.6% | -4.6% | +11.3% | 99% |
| Q4 2025 | +3.7% | +2.4% | +1.3% | 100% |
| Q3 2025 | +12.4% | +7.8% | +4.6% | 100% |
| Q2 2025 | +26.5% | +10.5% | +16.0% | 97% |
| Q1 2025 | -11.7% | -4.6% | -7.1% | 100% |
| Q4 2024 | -0.4% | +2.1% | -2.6% | 100% |
| Q3 2024 | +1.4% | +5.4% | -4.0% | 100% |

## Quarter by quarter

| Quarter | Value | Positions |
|---|---|---|
| Q2 2026 | $856.3M | 21 |
| Q1 2026 | $801.1M | 20 |
| Q4 2025 | $796.8M | 23 |
| Q3 2025 | $799.1M | 20 |
| Q2 2025 | $761.4M | 21 |
| Q1 2025 | $609.0M | 20 |
| Q4 2024 | $746.4M | 22 |
| Q3 2024 | $809.2M | 18 |
| Q2 2024 | $810.3M | 19 |
| Q1 2024 | $858.3M | 20 |
| Q4 2023 | $831.3M | 21 |
| Q3 2023 | $688.2M | 21 |