ACK Asset Management LLC
CIK: 1510940
Holdings (21)
Q2 2026 13F, quarter ended Jun 30, 2026, filed Aug 13, 2026
- WMS
WMS
$61.21M
390,000 sh7.15%+0.0% - HLIO
HLIO
$60.78M
681,000 sh7.10%-12.7% - LFUS
LFUS
$56.92M
125,000 sh6.65%-7.4% - JHX
JHX
$54.98M
2.10M sh6.42%+0.0% - GTX
GTX
$54.34M
1.50M sh6.35%New - CNM
CNM
$52.59M
1.09M sh6.14%+21.1% - EXP
EXP
$49.5M
220,000 sh5.78%+33.3% - ATS
ATS
$43.17M
1.50M sh5.04%-18.8% - ASTE
ASTE
$42.24M
690,276 sh4.93%-12.2% - MTRN
MTRN
$40.15M
135,000 sh4.69%-71.6% - BWA
BWA
$39.84M
600,000 sh4.65%New - DNOW
DNOW
$38.91M
3.00M sh4.54%New - MBC
MBC
$38.07M
3.70M sh4.45%+0.0% - SITE
SITE
$37.76M
330,000 sh4.41%+0.0% - SWIM
SWIM
$36.62M
5.66M sh4.28%+9.7% - CLFD
CLFD
$32.24M
810,200 sh3.76%+10.2% - ST
ST
$28.64M
600,000 sh3.34%New - AERO-SWX
AERO-SWX
$28.46M
1.08M sh3.32%+30.4% - SHLS
SHLS
$22.32M
2.25M sh2.61%New - EQPT
EQPT
$20.93M
1.06M sh2.44%New - MEI
MEI
$16.65M
877,500 sh1.94%New
| Security | Shares | Value | Change | Weight | Period |
|---|---|---|---|---|---|
 WMS WMS | 390,000 | $61.21M | +0.0% | 7.15% | Q2 2026 |
 HLIO HLIO | 681,000 | $60.78M | -12.7% | 7.10% | Q2 2026 |
 LFUS LFUS | 125,000 | $56.92M | -7.4% | 6.65% | Q2 2026 |
 JHX JHX | 2.10M | $54.98M | +0.0% | 6.42% | Q2 2026 |
 GTX GTX | 1.50M | $54.34M | New | 6.35% | Q2 2026 |
 CNM CNM | 1.09M | $52.59M | +21.1% | 6.14% | Q2 2026 |
 EXP EXP | 220,000 | $49.5M | +33.3% | 5.78% | Q2 2026 |
 ATS ATS | 1.50M | $43.17M | -18.8% | 5.04% | Q2 2026 |
 ASTE ASTE | 690,276 | $42.24M | -12.2% | 4.93% | Q2 2026 |
 MTRN MTRN | 135,000 | $40.15M | -71.6% | 4.69% | Q2 2026 |
 BWA BWA | 600,000 | $39.84M | New | 4.65% | Q2 2026 |
 DNOW DNOW | 3.00M | $38.91M | New | 4.54% | Q2 2026 |
 MBC MBC | 3.70M | $38.07M | +0.0% | 4.45% | Q2 2026 |
 SITE SITE | 330,000 | $37.76M | +0.0% | 4.41% | Q2 2026 |
 SWIM SWIM | 5.66M | $36.62M | +9.7% | 4.28% | Q2 2026 |
 CLFD CLFD | 810,200 | $32.24M | +10.2% | 3.76% | Q2 2026 |
 ST ST | 600,000 | $28.64M | New | 3.34% | Q2 2026 |
AERO-SWX AERO-SWX | 1.08M | $28.46M | +30.4% | 3.32% | Q2 2026 |
 SHLS SHLS | 2.25M | $22.32M | New | 2.61% | Q2 2026 |
 EQPT EQPT | 1.06M | $20.93M | New | 2.44% | Q2 2026 |
 MEI MEI | 877,500 | $16.65M | New | 1.94% | Q2 2026 |
1-21 of 21 holdings
Sector Allocation
SEC Filings
| Form | Description | Filed |
|---|---|---|
About ACK Asset Management LLC
ACK Asset Management LLC is an Investment Adviser that reports its US-listed stock and option positions to the SEC on Form 13F (CIK 1510940). Signal8 holds 20 13F filings from it. Its SEC filings list Connecticut as its state of incorporation.
Its most recent 13F holdings report covers Q2 2026 (the quarter ended Jun 30, 2026) and was filed on Aug 13, 2026. That report lists 21 securities, not counting options, up from 20 in Q1 2026.
Its five largest reported positions, in order, are WMS (WMS), HLIO (HLIO), LFUS (LFUS), JHX (JHX) and GTX (GTX). The next five are CNM (CNM), EXP (EXP), ATS (ATS), ASTE (ASTE) and MTRN (MTRN).
Recent 13F filings by ACK Asset Management LLC
- Q2 2026: 13F-HR filed Aug 13, 2026, listing 21 securities.
- Q1 2026: 13F-HR filed May 15, 2026, listing 20 securities.
- Q4 2025: 13F-HR filed Feb 13, 2026, listing 23 securities.
- Q3 2025: 13F-HR filed Nov 14, 2025, listing 20 securities.
- Q2 2025: 13F-HR filed Aug 13, 2025, listing 21 securities.
- Q1 2025: 13F-HR filed May 13, 2025, listing 20 securities.