Terminal · Institutions

Every 13F-reported equity position this quarter, with its quarter-over-quarter change — each row traces back to the SEC filing.

ACK Asset Management LLC 13F Holdings -- Portfolio & Top Positions (2026-06-30)

ACK Asset Management LLC (CIK 1510940) reported $856.3M across 20 reported positions in its SEC 13F filing for 2026-06-30. Largest positions: WMS ($61.2M, 7.15%), HLIO ($60.8M, 7.10%), LFUS ($56.9M, 6.65%), JHX ($55.0M, 6.42%), GTX ($54.3M, 6.35%). Source: SEC Form 13F.

RankTickerCompanyValue% PortfolioSharesAction
1WMSWMS$61.2M7.15%390,000Hold
2HLIOHLIO$60.8M7.10%681,000Trimmed
3LFUSLFUS$56.9M6.65%125,000Trimmed
4JHXJHX$55.0M6.42%2.1MHold
5GTXGTX$54.3M6.35%1.5MNew
6CNMCNM$52.6M6.14%1.1MAdded
7EXPEXP$49.5M5.78%220,000Added
8ATSATS$43.2M5.04%1.5MTrimmed
9ASTEASTE$42.2M4.93%690,276Trimmed
10MTRNMTRN$40.1M4.69%135,000Trimmed
11BWABWA$39.8M4.65%600,000New
12DNOWDNOW$38.9M4.54%3.0MNew
13MBCMBC$38.1M4.45%3.7MHold
14SITESITE$37.8M4.41%330,000Hold
15SWIMSWIM$36.6M4.28%5.7MAdded
16CLFDCLFD$32.2M3.76%810,200Added
17STST$28.6M3.34%600,000New
18AERO-SWX$28.5M3.32%1.1MAdded
19SHLSSHLS$22.3M2.61%2.3MNew
20EQPTEQPT$20.9M2.44%1.1MNew
21MEIMEI$16.6M1.94%877,500New
22CDNLCDNL$00.00%0Exited
23DXPEDXPE$00.00%0Exited
24CTSCTS$00.00%0Exited
25GVAGVA$00.00%0Exited

Source: SEC Form 13F filings · as of 2026-06-30