MASON CAPITAL MANAGEMENT LLC
13F Reported Value
ⓘ$607.0M
Holdings
9
Latest Filing
2026-06-30
Filing Quarter
Q2 2026
Portfolio Overview
MASON CAPITAL MANAGEMENT LLC disclosed 9 positions worth $607.0M in its Form 13F-HR for Q2 2026, led by $ATS (ATS Corp /ATS) at 77.8% of the equity portfolio, followed by $BKD and $NVRI.R45876. During the quarter the fund opened 2 new positions and exited 0 — including a new stake in $GRPN. The portfolio is most concentrated in Industrials (85.0% of disclosed assets). All figures are sourced directly from MASON CAPITAL MANAGEMENT LLC’s Form 13F-HR filing with the SEC under CIK 1218735.
AI Fund Analysis
StableSector Allocation
AUM History
Top Equity Holdings by Value
Quarterly Activity — Q2 2026
Click any card to unlockTop Holdings
- —
Quality
$472.1M16,404,170 sh - 44.1#1,931
Quality
$41.4M2,575,826 sh - 22.3#2,752
Quality
$38.9M1,770,959 sh - 42.7
Quality
$23.8M9,828,401 sh - 26.1
Quality
$15.8M657,144 sh - 24.5
Quality
$7.6M4,319,933 sh - 26.0
Quality
$4.7M3,109,621 sh CONTEXTLOGIC HOLDINGS INC - COM
—Quality
$2.6M291,341 shSIGNATURE BANK - COM
—Quality
$180.0K400,000 sh
| Company | Quality | Value | Shares |
|---|---|---|---|
 ATS Corp /ATS$ATS | — | $472.1M | 16,404,170 |
 Brookdale Senior Living Inc.$BKD | 44.1#1,931 | $41.4M | 2,575,826 |
 ENVIRI Corp$NVRI.R45876 | 22.3#2,752 | $38.9M | 1,770,959 |
 Clear Channel Outdoor Holdings, Inc.$CCO | 42.7 | $23.8M | 9,828,401 |
 Groupon, Inc.$GRPN | 26.1 | $15.8M | 657,144 |
 Ready Capital Corp$RC | 24.5 | $7.6M | 4,319,933 |
 JELD-WEN Holding, Inc.$JELD | 26.0 | $4.7M | 3,109,621 |
| CONTEXTLOGIC HOLDINGS INC - COM | — | $2.6M | 291,341 |
| SIGNATURE BANK - COM | — | $180.0K | 400,000 |
Unlock AI quality scores for every holding
32-signal composite ranking on each of MASON CAPITAL MANAGEMENT LLC's 9 positions.
Showing top 9 of 9 holdings.
Sector Allocation
Industrials
$515.6M
Healthcare
$41.4M
Technology
$23.8M
Communication Services
$15.8M
Real Estate
$7.6M
Other
$2.8M
Full Holdings — MASON CAPITAL MANAGEMENT LLC (Q2 2026)
All 9 disclosed positions from the latest Form 13F-HR, with quarter-over-quarter share changes and 13F Pro quality scores. Sourced from SEC EDGAR.
| # | Ticker | Company | Value | Weight | QoQ | Quality |
|---|---|---|---|---|---|---|
| 1 | $ATS | ATS Corp /ATS | $472.1M | 77.8% | +0% | — |
| 2 | $BKD | Brookdale Senior Living Inc. | $41.4M | 6.8% | +15% | 44.1 |
| 3 | $NVRI.R45876 | ENVIRI Corp | $38.9M | 6.4% | -61% | 22.3 |
| 4 | $CCO | Clear Channel Outdoor Holdings, Inc. | $23.8M | 3.9% | +0% | 42.7 |
| 5 | $GRPN | Groupon, Inc. | $15.8M | 2.6% | NEW | 26.1 |
| 6 | $RC | Ready Capital Corp | $7.6M | 1.3% | +0% | 24.5 |
| 7 | $JELD | JELD-WEN Holding, Inc. | $4.7M | 0.8% | +300% | 26 |
| 8 | — | CONTEXTLOGIC HOLDINGS INC - COM | $2.6M | 0.4% | NEW | — |
| 9 | — | SIGNATURE BANK - COM | $180,000 | 0.0% | +0% | — |
New Positions (2)
$GRPN Groupon, Inc.$15.8MBrowse Top Institutional Investors
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AI-Powered Hedge Fund Analysis: MASON CAPITAL MANAGEMENT LLC
13F Pro is an AI hedge fund tracker and stock research platform. For MASON CAPITAL MANAGEMENT LLC (SEC CIK: 1218735), the platform ingests every quarterly Form 13F filing and applies AI-powered analysis on top — 10 specialized AI analysts (value, growth, momentum, macro, activist, and more) debate the fund's top positions and publish AI-generated analysis with cited SEC sources.
Every holding in MASON CAPITAL MANAGEMENT LLC's portfolio is scored on a 32-signal AI quality ranking (ROIC, FCF margin, revenue growth, institutional flow, earnings quality, shareholder dilution, and more). Track accumulation and distribution quarter over quarter, identify conviction positions, and see AI stock analysis for each position — alongside 8,700+ other institutional filers and 2,800+ AI-ranked companies.