# MASON CAPITAL MANAGEMENT LLC: Form 13F holdings

An institutional investment manager in NEW YORK, NY. SEC CIK 1218735.

- Quarter ended: 2026-06-30
- Filed: 2026-08-14
- Reported value: $607.0m
- Positions: 9 (9 lines in the filing's table; lines for the same security and option type are added together here)
- Compared with: the 13F for the quarter ended 2026-03-31
- Filing: https://www.sec.gov/Archives/edgar/data/1218735/000110465926097052/

## Holdings

As filed, largest first. Reported value is what the manager stated at the quarter end (Jun 30, 2026), in US dollars; it is filing data, not a price. Weight is the share of the total reported value.

| Issuer | Class | Reported value | Weight | Shares | Put or call | Change on the quarter before |
| --- | --- | ---: | ---: | ---: | --- | --- |
| [ATS CORPORATION (ATS)](/companies/ats.md) | COM | $472.1m | 77.8% | 16,404,170 |  | Unchanged |
| [BROOKDALE SENIOR LIVING INC (BKD)](/companies/bkd.md) | COM | $41.4m | 6.8% | 2,575,826 |  | Added +342,085 |
| ENVIRI CORP | COM | $38.9m | 6.4% | 1,770,959 |  | Reduced −2,723,577 |
| CLEAR CHANNEL OUTDOOR HLDGS | COM | $23.8m | 3.9% | 9,828,401 |  | Unchanged |
| [GROUPON INC (GRPN)](/companies/grpn.md) | COM | $15.8m | 2.6% | 657,144 |  | New +657,144 |
| [READY CAPITAL CORP (RC)](/companies/rc.md) | REIT | $7.6m | 1.2% | 4,319,933 |  | Unchanged |
| [JELD-WEN HOLDING INC (JELD)](/companies/jeld.md) | COM | $4.7m | 0.8% | 3,109,621 |  | Added +2,332,736 |
| [CONTEXTLOGIC HOLDINGS INC (LOGC)](/companies/logc.md) | COM | $2.6m | 0.4% | 291,341 |  | New +291,341 |
| SIGNATURE BANK | COM | $180.0k | <0.1% | 400,000 |  | Unchanged |

Source: SEC EDGAR, Form 13F-HR, accession 0001104659-26-097052. Last ingested by Listed: Oct 22, 2026, 05:26 ET. No prices; not investment advice.