Mason Capital Management LLC 13F holdings, Q3 2025
Holdings as of September 30, 2025 · filings on SEC EDGAR · latest filing →
Mason Capital Management LLC disclosed 6 US equity positions worth $491.4m in its Q3 2025 13F filing. The largest position was ATS at 83.0% of the reported book, followed by KVUE and BKD. Against the Q2 2025 filing, it opened 3 new positions, added to 0 and reduced 0 among the top 6 holdings.
What did Mason Capital Management LLC own in Q3 2025? Top 6 positions
| # | Stock | Sector | Weight | Value | Shares | Δ shares | vs Q2 2025 |
|---|---|---|---|---|---|---|---|
| 1 | ATS ATS CORPORATION | 83.0% | $407.8m | 15,563,568 | 0% | held | |
| 2 | KVUE KENVUE INC | Consumer Defensive | 8.6% | $42.1m | 2,595,000 | – | new |
| 3 | BKD BROOKDALE SENIOR LIVING INC | Healthcare | 4.3% | $21.0m | 2,475,964 | – | new |
| 4 | CCO CLEAR CHANNEL OUTDOOR HLDGS | Communication Services | 3.2% | $15.5m | 9,828,401 | 0% | held |
| 5 | MLAB MESA LABORATORIES INC | Technology | 1.0% | $4.7m | 70,300 | – | new |
| 6 | SBNY SIGNATURE BANK | Financial Services | 0.1% | $260.0k | 400,000 | 0% | held |
Weights are shares of the reported long US equity book (options excluded). Values are as filed, normalised to whole dollars. Share changes compare against the immediately preceding filing only.