MASON CAPITAL MANAGEMENT LLC

All Holdings — 2025 Q4

AI Portfolio Summary
In 2025 Q4, MASON CAPITAL MANAGEMENT LLC maintained a portfolio of 10 distinct positions. The most significant new addition to the portfolio was SOLSTICE ADV MATERIA, which now represents 5.48% of the total fund value. They heavily accumulated shares in BROOKDALE SENIOR LIV, increasing their position by 44.8%. Conversely, MASON CAPITAL MANAGEMENT LLC completely exited their position in KENVUE INC.
PCA Score Concentration Risk
Risk ENB
Total Positions
10
Quarter
2025 Q4
Top Holding
ATS (76.3%)
Top 10 Concentration
100.0%
Turnover Rate
23.4%
Sector HHI
0.18
Items per page:
1-10 of 10
Stock History Sector / Type Port % Prev % Rank / Prev Conviction Change % Change Influence Shares Mkt Value Avg Cost Price Held 1st Owned Source Source Date Date Reported
ATS
ATS CORPORATION
Industrials 76.32% 82.99% #1
Prev: #1
10.0 no change no change
P
S
15,563,568 $428,620,663 2023 Q2 13F Filing 2025-12-31 2026-02-14 (Est.)
BKD
BROOKDALE SENIO...
Healthcare 6.89% 4.27% #2 1
Prev: #3
4.9 1,109,977 44.8%
P
S
3,585,941 $38,692,303 2025 Q3 13F Filing 2025-12-31 2026-02-14 (Est.)
SOLS
SOLSTICE ADV MA...
Basic Materials 5.48% #3
Prev: #—
4.2 633,801 no change
NEW
633,801 $30,790,053 2025 Q4 13F Filing 2025-12-31 2026-02-14 (Est.)
CCO
CLEAR CHANNEL O...
Communication Services 3.87% 3.16% #4
Prev: #4
1.5 no change no change
P
S
9,828,401 $21,720,766 2019 Q2 13F Filing 2025-12-31 2026-02-14 (Est.)
N/A
JBS N.V.
Unknown 3.35% #5
Prev: #—
3.3 1,306,000 no change
NEW
1,306,000 $18,832,520 13F Filing 2025-12-31 2026-02-14 (Est.)
BORR
BORR DRILLING L...
Energy 1.57% #6
Prev: #—
2.6 2,182,136 no change
NEW
2,182,136 $8,794,008 2025 Q4 13F Filing 2025-12-31 2026-02-14 (Est.)
RC
READY CAPITAL C...
Real Estate 1.47% #7
Prev: #—
2.6 3,776,139 no change
NEW
3,776,139 $8,231,983 2024 Q3 13F Filing 2025-12-31 2026-02-14 (Est.)
MLAB
MESA LABORATORI...
Technology 0.98% 0.96% #8 3
Prev: #5
0.4 no change no change
P
S
70,300 $5,518,550 2025 Q3 13F Filing 2025-12-31 2026-02-14 (Est.)
SBNY
SIGNATURE BANK
Financial Services 0.07% 0.05% #9 3
Prev: #6
0.0 no change no change
P
S
400,000 $404,000 2024 Q1 13F Filing 2025-12-31 2026-02-14 (Est.)
KVUE
KENVUE INC
Consumer Defensive 0.00% 8.57%
Sold All 😨
(Was: #2)
0.3 -2,595,000 -100.0%
CLOSED
$— 2025 Q3 13F Filing 2025-12-31 2026-02-14 (Est.)
Showing 1-10 of 10 holdings

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