Stocks/Funds/CIK 1218735

MASON CAPITAL MANAGEMENT LLC

long-term holderconcentrated
Quarterly 13F filings · Latest period 2026-03-31 · CIK 1218735
Assets
$613M
+43.5% YoY
Holdings
7
Lifetime alpha vs market
-9.38% annual
Average hold time
2.1 yr
median 1.0 yr

Quarterly history

Cum return +3% vs S&P +52% · α -50% lifetimeAUM $613M · peak $3.1BFlow $-34M (-6%)2016-062017-122019-062020-122022-062023-122025-062026-03
AUM ($B)fundS&P 500(gap = α)/ Flow in/out

Behavior signals (lifetime)

Dip response
+7.14%
adds when stocks drop
when a holding falls −10%+
Middle response
+3.44%
steady accumulation
Rally response
-14.23%
trims into rallies
when a holding rises +10%+

Top positions · 7

Ticker$ value% portYoYHold time
$463M75.5%3.0 yr
NVRIEnviri Corporation$88M14.4%+195.0%0.3 yr
BKDBrookdale Senior Living $31M5.0%+118.5%0.8 yr
CCOClear Channel Outdoor Ho$23M3.8%+113.5%7.0 yr
RCReady Capital Corporatio$7M1.1%-66.0%1.0 yr
JELDJELD-WEN Holding, Inc.$1M0.2%-79.2%0.3 yr
SBNYSignature Bank$0M0.0%-33.7%2.3 yr

Portfolio composition (YoY)

Industry mix
Unknown75.5%-15.3pp$463M
Waste Management14.4%$88M
Medical - Care Facilities5.0%$31M
Advertising Agencies3.8%+1.2pp$23M
REIT - Mortgage1.1%$7M
Construction0.2%$1M
Banks - Regional0.0%-0.0pp$0M
Country
Unknown75.5%-15.3pp
US24.5%+15.3pp
Top 5: 99.8% · Top 10: 100.0% · Top 25: 100.0%

Winners

TickerPrev $PnLYoY %
CCO$11M+0.01B113.5%
SBNY$0M-0.00B-33.7%

Losers

TickerPrev $PnLYoY %
SBNY$0M-0.00B-33.7%

Top buys this quarter · 4

NVRI Enviri Corporationnew+$88M
JELD JELD-WEN Holding, Inc.new+$1M
RC Ready Capital Corporation+$7M
+$0M

Top sells this quarter · 5

SOLS Solstice Advanced Materials Inexit$48M
BKD Brookdale Senior Living Inc.$18M
MLAB Mesa Laboratories, Inc.exit$6M
exit$0M
exit$0M

Quarterly history (TTM returns)

PeriodAUM# PosReturn (1yr)SPY (1yr)Alpha (1yr)Flow
2026-03-31$613M7+37.00%+17.59%+19.41%-0.03B
2025-12-31$562M9-3.01%+17.72%-20.72%-0.01B
2025-09-30$491M6-21.41%+17.52%-38.93%-0.01B
2025-06-30$512M4-16.08%+14.94%-31.02%+0.07B
2025-03-31$427M5-22.04%+8.30%-30.35%+0.04B
2024-12-31$471M4-20.04%+24.89%-44.93%-0.00B
2024-09-30$503M6-1.85%+36.04%-37.88%-0.06B
2024-06-30$538M6-1.61%+24.49%-26.10%-0.17B
2024-03-31$728M6+4.00%+29.62%-25.62%-0.02B
2023-12-31$894M7+26.12%+26.18%-0.06%-0.45B
2023-09-30$1.16B8+35.91%+21.57%+14.34%+0.08B
2023-06-30$1.03B10+35.94%+19.42%+16.51%+0.79B
2023-03-31$234M12-7.63%-7.82%+0.19%-0.00B
2022-12-31$231M12+24.13%+7.56%+16.56%-0.09B
2022-09-30$258M12+5.39%-4.93%+10.32%-0.04B
2022-06-30$281M16-30.33%-16.11%-14.22%+0.06B