Holders — by stockHoldings — by fund
ACK Asset Management LLC
Everything this manager disclosed owning in US-listed stocks — its complete Form 13F portfolio · as of 2026-06-30 · filed with the SEC up to 45 days after quarter end · CIK 0001510940
$856.3M
disclosed book value
21
positions
7.1%
largest position share
Positions, as of 2026-06-30
top 21 of 21 · 13F covers long US-listed positions only — cash, bonds, private and foreign stakes are not disclosed · PUT/CALL tags = options positions (share-equivalents), not shares held
| # | Issuer | Shares | Value | % of book |
|---|---|---|---|---|
| 1 | WMSWMS | 390,000 | $61.2M | 7.1% |
| 2 | HLIOHLIO | 681,000 | $60.8M | 7.1% |
| 3 | LFUSLFUS | 125,000 | $56.9M | 6.6% |
| 4 | JHX | 2.1M | $55.0M | 6.4% |
| 5 | GTXGTX | 1.5M | $54.3M | 6.3% |
| 6 | CNMCNM | 1.1M | $52.6M | 6.1% |
| 7 | EXPEXP | 220,000 | $49.5M | 5.8% |
| 8 | ATSATS | 1.5M | $43.2M | 5% |
| 9 | ASTEASTE | 690,276 | $42.2M | 4.9% |
| 10 | MTRNMTRN | 135,000 | $40.1M | 4.7% |
| 11 | BWABWA | 600,000 | $39.8M | 4.7% |
| 12 | DNOWDNOW | 3.0M | $38.9M | 4.5% |
| 13 | MBCMBC | 3.7M | $38.1M | 4.4% |
| 14 | SITESITE | 330,000 | $37.8M | 4.4% |
| 15 | SWIMSWIM | 5.7M | $36.6M | 4.3% |
| 16 | CLFDCLFD | 810,200 | $32.2M | 3.8% |
| 17 | ST | 600,000 | $28.6M | 3.3% |
| 18 | AERO-SWX | 1.1M | $28.5M | 3.3% |
| 19 | SHLSSHLS | 2.3M | $22.3M | 2.6% |
| 20 | EQPTEQPT | 1.1M | $20.9M | 2.4% |
| 21 | MEIMEI | 877,500 | $16.6M | 1.9% |
Source: SEC Form 13F-HR, reporting period 2026-06-30. Values are the manager's filed June-30-style quarter-end marks, not live prices. Research, not investment advice.