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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