Mason Capital Management LLC
In its 13F for Q1 2024 (holdings as of March 31, 2024, filed May 15, 2024), Mason Capital Management LLC reported 6 stock positions worth $727.8 million. Its top holding was Ats (ATS) at 89.9% of the portfolio, followed by Barnes (4.0%) and Seadrill (SDRL, 2.8%). Compared with Q4 2023, it opened 2 new positions, sold out of 3, added to 2 and reduced 2. The biggest buy was Clear Channel Outdoor Holdin (CCO, shares +311%) and the biggest sale an exit from SS Industrial Select Sector (XLI).
- Most Recent 13F
- Q2 2026
- Location
- NEW YORK, NY
- CIK
- 0001218735
- Portfolio Value
- $727.8M (Q1 2024)
- SEC Filing
- 0001104659-24-062078 ↗ filed May 15, 2024
Holdings Value
Holdings 6 stocks · $727.8M
| ATS Ats Corp. | 89.86% | 14,349,765 | $654.1M | Reduce -19.6% |
| BARNES GROUP INC | 4.03% | 790,122 | $29.4M | Reduce -17.8% |
| SDRL Seadrill Limited | 2.75% | 398,629 | $20.1M | Add +1.3% |
| CCO Clear Channel Outdoor Holdin | 2.23% | 9,828,401 | $16.2M | Add +310.5% |
| MDRX Veradigm Inc. | 0.99% | 938,238 | $7.2M | New |
| SBNY Signature Bank | 0.13% | 400,000 | $920K | New |
Portfolio Sells Q4 2023 → Q1 2024
| XLI SS Industrial Select Sector | Sold out | 0.00% | −7.04 |
| CLBR.U Colombier Acquis Corp. II | Sold out | 0.00% | −0.85 |
| FORWARD PHARMA A/S | Sold out | 0.00% | −0.02 |
| BARNES GROUP INC | Reduce -17.8% | 4.03% | +0.52 |
| ATS Ats Corp. | Reduce -19.6% | 89.86% | +3.86 |
Portfolio Buys Q4 2023 → Q1 2024
All Filings
| Quarter | Positions | 13F Reported Value | Top Holdings |
|---|---|---|---|
| Q2 2026 | 9 | $607.0M | ATS, BKD, NVRI, CCO, GRPN |
| Q1 2026 | 7 | $612.9M | ATS, NVRI, BKD, CCO, RC |
| Q4 2025 | 9 | $561.6M | ATS, BKD, SOLS, CCO, JBS |
| Q3 2025 | 6 | $491.4M | ATS, KVUE, BKD, CCO, MLAB |
| Q2 2025 | 4 | $511.5M | ATS, CCO, CCIR, SBNY |
| Q1 2025 | 5 | $427.2M | ATS, PARAA, CCO, CCIR, SBNY |
| Q4 2024 | 4 | $470.5M | ATS, CCO, RC, SBNY |
| Q3 2024 | 6 | $502.6M | ATS, MDRX, BARNES GROUP INC, CCO, RC |
| Q2 2024 | 6 | $538.2M | ATS, BARNES GROUP INC, CCO, MDRX, IIIV |
| Q1 2024 | 6 | $727.8M | ATS, BARNES GROUP INC, SDRL, CCO, MDRX |