Mason Capital Management LLC
In its 13F for Q1 2025 (holdings as of March 31, 2025, filed May 15, 2025), Mason Capital Management LLC reported 5 stock positions worth $427.2 million. Its top holding was Ats (ATS) at 90.8% of the portfolio, followed by Paramount Global Class B (PARAA, 5.7%) and Clear Channel Outdoor Holdin (CCO, 2.6%). Compared with Q4 2024, it opened 2 new positions, sold out of 1 and added to 1. The biggest buy was a new position in Paramount Global Class B (PARAA) and the biggest sale an exit from Ready Capital (RC).
- Most Recent 13F
- Q2 2026
- Location
- NEW YORK, NY
- CIK
- 0001218735
- Portfolio Value
- $427.2M (Q1 2025)
- SEC Filing
- 0001104659-25-049417 ↗ filed May 15, 2025
Holdings Value
Holdings 5 stocks · $427.2M
Portfolio Sells Q4 2024 → Q1 2025
| RC Ready Capital Corp. | Sold out | 0.00% | −0.40 |
Portfolio Buys Q4 2024 → Q1 2025
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 |