Mason Capital Management LLC

In its 13F for Q2 2025 (holdings as of June 30, 2025, filed August 14, 2025), Mason Capital Management LLC reported 4 stock positions worth $511.5 million. Its top holding was Ats (ATS) at 97.0% of the portfolio, followed by Clear Channel Outdoor Holdin (CCO, 2.2%) and Cohen Circle Acquisitio Class A (CCIR, 0.7%). Compared with Q1 2025, it sold out of 1. The biggest sale was an exit from Paramount Global Class B (PARAA).

Most Recent 13F
Q2 2026
Location
NEW YORK, NY
CIK
0001218735
Portfolio Value
$511.5M (Q2 2025)
SEC Filing
0001104659-25-078546 ↗ filed Aug 14, 2025

Holdings Value

0$200.0M$400.0M$600.0M$800.0M Q1 2024: $727.8M Q1 2024 Q2 2024: $538.2M Q2 2024 Q3 2024: $502.6M Q3 2024 Q4 2024: $470.5M Q4 2024 Q1 2025: $427.2M Q1 2025 Q2 2025: $511.5M $511.5M Q2 2025 Q3 2025: $491.4M Q3 2025 Q4 2025: $561.6M Q4 2025 Q1 2026: $612.9M Q1 2026 Q2 2026: $607.0M Q2 2026

Holdings 4 stocks · $511.5M
ATS Ats Corp. 97.00% 15,563,568 $496.2M No change
CCO Clear Channel Outdoor Holdin 2.25% 9,828,401 $11.5M No change
CCIR Cohen Circle Acquisitio Class A 0.70% 325,000 $3.6M No change
SBNY Signature Bank 0.06% 400,000 $300K No change

Portfolio Sells Q1 2025 → Q2 2025
PARAA Paramount Global Class B Sold out 0.00% −5.68

Portfolio Buys Q1 2025 → Q2 2025
None this quarter.

All Filings

QuarterPositions13F Reported ValueTop Holdings
Q2 2026 9$607.0MATS, BKD, NVRI, CCO, GRPN
Q1 2026 7$612.9MATS, NVRI, BKD, CCO, RC
Q4 2025 9$561.6MATS, BKD, SOLS, CCO, JBS
Q3 2025 6$491.4MATS, KVUE, BKD, CCO, MLAB
Q2 2025 4$511.5MATS, CCO, CCIR, SBNY
Q1 2025 5$427.2MATS, PARAA, CCO, CCIR, SBNY
Q4 2024 4$470.5MATS, CCO, RC, SBNY
Q3 2024 6$502.6MATS, MDRX, BARNES GROUP INC, CCO, RC
Q2 2024 6$538.2MATS, BARNES GROUP INC, CCO, MDRX, IIIV
Q1 2024 6$727.8MATS, BARNES GROUP INC, SDRL, CCO, MDRX