Mason Capital Management LLC

Activist investor & 5%+ owner · SC 13D/13G filings

Total Filings

Stocks Covered

Latest Filing

Jan 29, 2026

Filings

Veradigm Inc.

SC 13G · Jan 29, 2026

5.8%

6.3M shares

ATS Corporation

SC 13G/A · Nov 13, 2024

15.2%

14.9M shares

ATS Corporation

SC 13G · Feb 14, 2024

18.2%

17.8M shares

PSQ Holdings, Inc. (f/k/a Colombier Acquisition Corp.)

SC 13D/A · Jul 21, 2023

0.0%

0 shares

Colombier Acquisition Corp.

SC 13D/A · Jul 19, 2023

7.5%

1.3M shares

Colombier Acquisition Corp.

SC 13D · Jun 26, 2023

7.5%

1.3M shares

Clear Channel Outdoor Holdings, Inc.

SC 13G/A · Feb 14, 2022

4.7%

22.1M shares

CoreCivic, Inc.

SC 13D/A · Jan 5, 2022

3.7%

4.4M shares