Mason Capital Management LLC
In its 13F for Q3 2024 (holdings as of September 30, 2024, filed November 14, 2024), Mason Capital Management LLC reported 6 stock positions worth $502.6 million. Its top holding was Ats (ATS) at 86.2% of the portfolio, followed by Veradigm (MDRX, 4.8%) and Barnes (4.4%). Compared with Q2 2024, it opened 1 new position, sold out of 1, added to 2 and reduced 1. The biggest buy was Veradigm (MDRX, shares +166%) and the biggest sale Barnes (shares −48%).
- Most Recent 13F
- Q2 2026
- Location
- NEW YORK, NY
- CIK
- 0001218735
- Portfolio Value
- $502.6M (Q3 2024)
- SEC Filing
- 0001104659-24-118983 ↗ filed Nov 14, 2024
Holdings Value
Holdings 6 stocks · $502.6M
| ATS Ats Corp. | 86.21% | 14,914,765 | $433.3M | Add +3.9% |
| MDRX Veradigm Inc. filed as ALLSCRIPTS HEALTHCARE SOLUTI | 4.82% | 2,499,709 | $24.2M | Add +166.4% |
| BARNES GROUP INC | 4.41% | 548,218 | $22.2M | Reduce -47.8% |
| CCO Clear Channel Outdoor Holdin | 3.13% | 9,828,401 | $15.7M | No change |
| RC Ready Capital Corp. | 1.27% | 838,856 | $6.4M | New |
| SBNY Signature Bank | 0.16% | 400,000 | $800K | No change |
Portfolio Sells Q2 2024 → Q3 2024
| BARNES GROUP INC | Reduce -47.8% | 4.41% | −3.67 |
| IIIV I3 Verticals Inc. Class A | Sold out | 0.00% | −1.38 |
Portfolio Buys Q2 2024 → Q3 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 |