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MASON CAPITAL MANAGEMENT LLC

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13F filer, CIK 1218735, NEW YORK, NY

MASON CAPITAL MANAGEMENT LLC reported $607,022,468 across 9 holdings for the quarter ended 2026-06-30, in a 13F-HR filed 2026-08-14.

Filed (acceptance time not in the bulk data set), ingested 13F-HR 0001104659-26-097052

Period
2026-06-30
Reported value
$607M
Holdings
9
Top 10 weight
100%
New
2
Sold out
0

Largest buys vs the previous quarter

SecurityShares changeApprox. value
GRPNnew+657,144$15.8M
BKDadded+342,085$5.5M
JELDadded+2,332,736$3.5M
LOGCnew+291,341$2.59M

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
NVRIreduced-2,723,577-$59.8M

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, Q2 2026

Share positions as resolved from 13F-HR 0001104659-26-097052, largest first. % of portfolio is the value over $606,842,468, 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; 2024Q3: 14,914,765 shares; 2024Q4: 14,914,765 shares; 2025Q1: 15,563,568 shares; 2025Q2: 15,563,568 shares; 2025Q3: 15,563,568 shares; 2025Q4: 15,563,568 shares; 2026Q1: 16,404,170 shares; 2026Q2: 16,404,170 shares 16,404,170$472M77.8%0Timeline
BKDBROOKDALE SR LIVING INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q3: not reported; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: 2,475,964 shares; 2025Q4: 3,585,941 shares; 2026Q1: 2,233,741 shares; 2026Q2: 2,575,826 shares 2,575,826$41.4M6.83%+342,085Timeline
NVRIENVIRI CORPQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q3: not reported; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: not reported; 2025Q4: not reported; 2026Q1: 4,494,536 shares; 2026Q2: 1,770,959 shares 1,770,959$38.9M6.41%-2,723,577Timeline
CCOCLEAR CHANNEL OUTDOOR HLDGSQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q3: 9,828,401 shares; 2024Q4: 9,828,401 shares; 2025Q1: 9,828,401 shares; 2025Q2: 9,828,401 shares; 2025Q3: 9,828,401 shares; 2025Q4: 9,828,401 shares; 2026Q1: 9,828,401 shares; 2026Q2: 9,828,401 shares 9,828,401$23.8M3.92%0Timeline
GRPNGROUPON INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q3: not reported; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: not reported; 2025Q4: not reported; 2026Q1: not reported; 2026Q2: 657,144 shares 657,144$15.8M2.61%newTimeline
RCREADY CAPITAL CORPQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q3: 838,856 shares; 2024Q4: 278,856 shares; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: not reported; 2025Q4: 3,776,139 shares; 2026Q1: 4,319,933 shares; 2026Q2: 4,319,933 shares 4,319,933$7.56M1.25%0Timeline
JELDJELD-WEN HLDG INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q3: not reported; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: not reported; 2025Q4: not reported; 2026Q1: 776,885 shares; 2026Q2: 3,109,621 shares 3,109,621$4.66M0.77%+2,332,736Timeline
LOGCCONTEXTLOGIC HOLDINGS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q3: not reported; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: not reported; 2025Q4: not reported; 2026Q1: not reported; 2026Q2: 291,341 shares 291,341$2.59M0.43%newTimeline
SBNYSIGNATURE BANKQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2024Q3: 400,000 shares; 2024Q4: 400,000 shares; 2025Q1: 400,000 shares; 2025Q2: 400,000 shares; 2025Q3: 400,000 shares; 2025Q4: 400,000 shares; 2026Q1: 400,000 shares; 2026Q2: 400,000 shares 400,000$180K0Value about 1/1,000 of the price other filers imply, kept as filed and left out of ratios.Timeline

How Q2 2026 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 0001104659-26-097052 base2026-08-14acceptance time not in the bulk data set

Filings

Every filing of this filer: 13F reports and notices, the 13D and 13G it filed or is a reporting person of, and Forms 3, 4 and 5 it reported as an owner.

FilingSubjectFiledAcceptedIngested
13F-HR 0001104659-26-097052 Quarter ended 2026-06-302026-08-14acceptance time not in the bulk data set
13F-HR 0001104659-26-062410 Quarter ended 2026-03-312026-05-15acceptance time not in the bulk data set
13F-HR 0001104659-26-016335 Quarter ended 2025-12-312026-02-17acceptance time not in the bulk data set
13F-HR 0001104659-25-111862 Quarter ended 2025-09-302025-11-14acceptance time not in the bulk data set
13F-HR 0001104659-25-078546 Quarter ended 2025-06-302025-08-14acceptance time not in the bulk data set
13F-HR 0001104659-25-049417 Quarter ended 2025-03-312025-05-15acceptance time not in the bulk data set
13F-HR 0001104659-25-014023 Quarter ended 2024-12-312025-02-14acceptance time not in the bulk data set
13F-HR 0001104659-24-118983 Quarter ended 2024-09-302024-11-14acceptance time not in the bulk data set
13F-HR 0001104659-24-089695 Quarter ended 2024-06-302024-08-14acceptance time not in the bulk data set
13F-HR 0001104659-24-062078 Quarter ended 2024-03-312024-05-15acceptance time not in the bulk data set
13F-HR 0001104659-24-024372 Quarter ended 2023-12-312024-02-15acceptance time not in the bulk data set
13F-HR 0001104659-23-118259 Quarter ended 2023-09-302023-11-14acceptance time not in the bulk data set
13F-HR 0001104659-23-091289 Quarter ended 2023-06-302023-08-14acceptance time not in the bulk data set
13F-HR 0001104659-23-060733 Quarter ended 2023-03-312023-05-15acceptance time not in the bulk data set
13F-HR 0001104659-23-021566 Quarter ended 2022-12-312023-02-14acceptance time not in the bulk data set
13F-HR 0001104659-22-118705 Quarter ended 2022-09-302022-11-14acceptance time not in the bulk data set
13F-HR 0001104659-22-091318 Quarter ended 2022-06-302022-08-15acceptance time not in the bulk data set
13F-HR 0001104659-22-061284 Quarter ended 2022-03-312022-05-16acceptance time not in the bulk data set
13F-HR 0001104659-22-022969 Quarter ended 2021-12-312022-02-14acceptance time not in the bulk data set
13F-HR 0001104659-21-139130 Quarter ended 2021-09-302021-11-15acceptance time not in the bulk data set
13F-HR 0001104659-21-106273 Quarter ended 2021-06-302021-08-16acceptance time not in the bulk data set
13F-HR 0001104659-21-068026 Quarter ended 2021-03-312021-05-17acceptance time not in the bulk data set
13F-HR 0001104659-21-023776 Quarter ended 2020-12-312021-02-16acceptance time not in the bulk data set
13F-HR/A 0001104659-20-130856 Quarter ended 2020-09-302020-12-01acceptance time not in the bulk data set
13F-HR 0001104659-20-124970 Quarter ended 2020-09-302020-11-13acceptance time not in the bulk data set
13F-HR 0001104659-20-095094 Quarter ended 2020-06-302020-08-14acceptance time not in the bulk data set
13F-HR 0001104659-20-062152 Quarter ended 2020-03-312020-05-15acceptance time not in the bulk data set
13F-HR 0001104659-20-021600 Quarter ended 2019-12-312020-02-14acceptance time not in the bulk data set
13F-HR 0001104659-19-063857 Quarter ended 2019-09-302019-11-14acceptance time not in the bulk data set
13F-HR 0001144204-19-039769 Quarter ended 2019-06-302019-08-14acceptance time not in the bulk data set
13F-HR 0001144204-19-026211 Quarter ended 2019-03-312019-05-15acceptance time not in the bulk data set
13F-HR 0001144204-19-007563 Quarter ended 2018-12-312019-02-14acceptance time not in the bulk data set
13F-HR 0001144204-18-060162 Quarter ended 2018-09-302018-11-15acceptance time not in the bulk data set
13F-HR 0001144204-18-044576 Quarter ended 2018-06-302018-08-14acceptance time not in the bulk data set
13F-HR 0001144204-18-028699 Quarter ended 2018-03-312018-05-15acceptance time not in the bulk data set
13F-HR 0001144204-18-008683 Quarter ended 2017-12-312018-02-14acceptance time not in the bulk data set
13F-HR 0001144204-17-058901 Quarter ended 2017-09-302017-11-14acceptance time not in the bulk data set
13F-HR 0001144204-17-043031 Quarter ended 2017-06-302017-08-14acceptance time not in the bulk data set
13F-HR 0001144204-17-027315 Quarter ended 2017-03-312017-05-15acceptance time not in the bulk data set
13F-HR 0001144204-17-008450 Quarter ended 2016-12-312017-02-14acceptance time not in the bulk data set
13F-HR 0001144204-16-134466 Quarter ended 2016-09-302016-11-15acceptance time not in the bulk data set
13F-HR 0001144204-16-119407 Quarter ended 2016-06-302016-08-15acceptance time not in the bulk data set
13F-HR 0001144204-16-102565 Quarter ended 2016-03-312016-05-16acceptance time not in the bulk data set
13F-HR 0001144204-16-082654 Quarter ended 2015-12-312016-02-16acceptance time not in the bulk data set
13F-HR 0001144204-15-066005 Quarter ended 2015-09-302015-11-16acceptance time not in the bulk data set
13F-HR 0001144204-15-049865 Quarter ended 2015-06-302015-08-14acceptance time not in the bulk data set
13F-HR 0001144204-15-031551 Quarter ended 2015-03-312015-05-15acceptance time not in the bulk data set
13F-HR 0001144204-15-010130 Quarter ended 2014-12-312015-02-17acceptance time not in the bulk data set
13F-HR 0001144204-14-068776 Quarter ended 2014-09-302014-11-14acceptance time not in the bulk data set
13F-HR 0001144204-14-050180 Quarter ended 2014-06-302014-08-14acceptance time not in the bulk data set
13F-HR 0001144204-14-031155 Quarter ended 2014-03-312014-05-15acceptance time not in the bulk data set
13F-HR 0001144204-14-009921 Quarter ended 2013-12-312014-02-14acceptance time not in the bulk data set
13F-HR 0001144204-13-061943 Quarter ended 2013-09-302013-11-14acceptance time not in the bulk data set
13F-HR 0001144204-13-045882 Quarter ended 2013-06-302013-08-14acceptance time not in the bulk data set