Skip to content
Disclosery

MASON CAPITAL MANAGEMENT LLC

Follow

13F filer, CIK 1218735, NEW YORK, NY

MASON CAPITAL MANAGEMENT LLC reported $427,192,325 across 5 holdings for the quarter ended 2025-03-31, in a 13F-HR filed 2025-05-15.

Filed (acceptance time not in the bulk data set), ingested 13F-HR 0001104659-25-049417

Period
2025-03-31
Reported value
$427M
Holdings
5
Top 10 weight
100%
New
2
Sold out
1

Largest buys vs the previous quarter

SecurityShares changeApprox. value
PARAMOUNT GLOBALnew+2,027,408$24.2M
ATSadded+648,803$16.2M
COHENCIRCLEACQUISITIONCORnew+325,000$3.64M

Ranked by the share change valued at this quarter's implied price (value over shares in the 13F). A position sold out is valued at the previous quarter's price, its last report.

Largest sells vs the previous quarter

SecurityShares changeApprox. value
RCexited-278,856-$1.9M

Ranked by the share change valued at this quarter's implied price (value over shares in the 13F). A position sold out is valued at the previous quarter's price, its last report.

Holdings, Q1 2025

Share positions as resolved from 13F-HR 0001104659-25-049417, largest first. % of portfolio is the value over $427,192,325, the sum of the share positions whose value is usable for ratios (method).

SecurityHistorySharesValue% of portfolioChangeLatest eventTimeline
ATSATS CORPORATIONQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q2: restricted; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 14,914,765 shares; 2024Q4: 14,914,765 shares; 2025Q1: 15,563,568 shares 15,563,568$388M90.83%+648,803Timeline
PARAMOUNT GLOBALPARAMOUNT GLOBALQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q2: restricted; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: not reported; 2024Q4: not reported; 2025Q1: 2,027,408 shares 2,027,408$24.2M5.68%new
CCOCLEAR CHANNEL OUTDOOR HLDGSQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q2: restricted; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 9,828,401 shares; 2024Q4: 9,828,401 shares; 2025Q1: 9,828,401 shares 9,828,401$10.9M2.55%0Timeline
COHENCIRCLEACQUISITIONCORCOHENCIRCLEACQUISITIONCORQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q2: restricted; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: not reported; 2024Q4: not reported; 2025Q1: 325,000 shares 325,000$3.64M0.85%new
SBNYSIGNATURE BANKQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q2: restricted; 2023Q3: restricted; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 400,000 shares; 2024Q4: 400,000 shares; 2025Q1: 400,000 shares 400,000$392K0.09%0Timeline

Sold out in Q1 2025

Positions in the previous quarter's report that this quarter's report no longer lists.

SecurityShares beforeValue beforeType
RCREADY CAPITAL CORP278,856$1.9Mshares

How Q1 2025 was built

Available 13F filings of this filer for the quarter and their roles: the base report is the latest original or restatement, NEW HOLDINGS amendments filed after it are added (method).

FilingRoleAmendmentFiledAcceptedIngested
13F-HR 0001104659-25-049417 base2025-05-15acceptance time not in the bulk data set