MASON CAPITAL MANAGEMENT LLC
13F Reported Value
ⓘ$612.9M
Holdings
7
Latest Filing
2026-03-31
Filing Quarter
Q1 2026
Portfolio Overview
MASON CAPITAL MANAGEMENT LLC disclosed 7 positions worth $612.9M in its Form 13F-HR for Q1 2026, led by $ATS (ATS Corp /ATS) at 75.5% of the equity portfolio, followed by $NVRI and $BKD. During the quarter the fund opened 2 new positions and exited 4 — including a new stake in $NVRI and a full exit from $SOLS. The portfolio is most concentrated in Industrials (90.0% 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 — Q1 2026
Click any card to unlockTop Holdings
- —
Quality
$462.6M16,404,170 sh - 35.6#2,133
Quality
$88.2M4,494,536 sh - 43.1#1,826
Quality
$30.6M2,233,741 sh - 47.1
Quality
$23.3M9,828,401 sh - —
Quality
$7.0M4,319,933 sh - 25.4
Quality
$963.3K776,885 sh SIGNATURE BANK
—Quality
$260.0K400,000 sh
| Company | Quality | Value | Shares |
|---|---|---|---|
 ATS Corp /ATS$ATS | — | $462.6M | 16,404,170 |
 ENVIRI Corp$NVRI | 35.6#2,133 | $88.2M | 4,494,536 |
 Brookdale Senior Living Inc.$BKD | 43.1#1,826 | $30.6M | 2,233,741 |
 Clear Channel Outdoor Holdings, Inc.$CCO | 47.1 | $23.3M | 9,828,401 |
 Ready Capital Corp$RC | — | $7.0M | 4,319,933 |
 JELD-WEN Holding, Inc.$JELD | 25.4 | $963.3K | 776,885 |
| SIGNATURE BANK | — | $260.0K | 400,000 |
Unlock AI quality scores for every holding
32-signal composite ranking on each of MASON CAPITAL MANAGEMENT LLC's 7 positions.
Showing top 7 of 7 holdings.
Sector Allocation
Industrials
$551.7M
Healthcare
$30.6M
Technology
$23.3M
Real Estate
$7.0M
Other
$260,000
Full Holdings — MASON CAPITAL MANAGEMENT LLC (Q1 2026)
All 7 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 | $462.6M | 75.5% | +5% | — |
| 2 | $NVRI | ENVIRI Corp | $88.2M | 14.4% | NEW | 35.6 |
| 3 | $BKD | Brookdale Senior Living Inc. | $30.6M | 5.0% | -38% | 43.1 |
| 4 | $CCO | Clear Channel Outdoor Holdings, Inc. | $23.3M | 3.8% | +0% | 47.1 |
| 5 | $RC | Ready Capital Corp | $7.0M | 1.1% | +14% | — |
| 6 | $JELD | JELD-WEN Holding, Inc. | $963,337 | 0.2% | NEW | 25.4 |
| 7 | — | SIGNATURE BANK | $260,000 | 0.0% | +0% | — |
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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.