§ 13F · FUND PROFILE
MASON CAPITAL MANAGEMENT LLC.
Institutional filer · behavioral pattern: Other. Summary pending.
AUM · $491M (13F)Positions · 6Turnover · — · Q1Filed · May 15, 2026
CONCENTRATION
—
Top 10 holdings
NEW BUYS
0
+$89M deployed
EXITS
0
No exits
SECTOR SHIFT
—
No prior quarter data
3YR HIT RATE
—
Top-5 overlap
§ 01 · TOP HOLDINGS
The book · Q1 2026
FILED MAY 15, 2026
| # | Ticker | Name | Shares | $ value | % port | Δ Q1 |
|---|---|---|---|---|---|---|
| 1 | ATS | ATS CORPORATION | 16.40M | $463M | 75.5% | +5% |
| 2 | NVRI | ENVIRI CORP | 4.49M | $88M | 14.4% | NEW |
| 3 | BKD | BROOKDALE SENIOR LIVING INC | 2.23M | $31M | 5.0% | −38% |
| 4 | CCO | CLEAR CHANNEL OUTDOOR HLDGS | 9.83M | $23M | 3.8% | ±0% |
| 5 | RC | READY CAPITAL CORP | 4.32M | $7M | 1.1% | +14% |
| 6 | JELD | JELD-WEN HOLDING INC | 777K | $963K | 0.2% | NEW |
| 7 | SBNY | SIGNATURE BANK | 400K | $260K | 0.0% | ±0% |
§ 02 · SECTOR ALLOCATION
Where the money is
Sector data pending
§ 03 · THE MASON SIGNAL
AC read
MASON CAPITAL MANAGEMENT LLC is a Other fund managing $491 million in assets. The fund runs a focused portfolio of just 6 positions.
Read the full dossier →§ 04 · FILING HISTORY
Q-by-Q deltas
2 FILINGS
Q1 2026
Steady book
+0 buys · −0 exits · 0 changed
Q4 2025
Steady book
+0 buys · −0 exits · 0 changed
Q3 2025
Steady book
+0 buys · −0 exits · 0 changed
Q1 2025
Steady book
+0 buys · −0 exits · 0 changed