SEC Form 4 · Updated Daily
TUSK
— MAMMOTH ENERGY SERVICES, INC. OwnershipInsider and institutional ownership derived from SEC Form 4 filings. Click any owner to see their holdings across every company they’ve filed on, and how their position has changed over time.
Current Reporting Owners
| Owner | Role | Shares Owned | As Of | Last Activity |
|---|---|---|---|---|
| Wexford Spectrum Trading LTD | 10%+ Owner · Director | 22,045,273 | 2019-11-20 | P |
| MEH SUB LLC | 10%+ Owner · Director | 22,045,273 | 2019-11-20 | P |
| Wexford Catalyst Trading LTD | 10%+ Owner · Director | 22,045,273 | 2019-11-20 | P |
| Mammoth Energy Holdings LLC | 10%+ Owner · Director | 20,445,923 | 2016-10-19 | S |
| WEXFORD CAPITAL LP | 10%+ Owner · Director | 10,620,789 | 2026-06-17 | P |
| Wexford GP LLC | 10%+ Owner · Director | 10,620,789 | 2026-06-17 | P |
| DAVIDSON CHARLES E | 10%+ Owner · Director | 10,620,789 | 2026-06-17 | P |
| JACOBS JOSEPH | 10%+ Owner · Director | 10,620,789 | 2026-06-17 | P |
| GPOR Distribution Trust | 10%+ Owner | 9,829,548 | 2021-06-30 | — |
| GULFPORT ENERGY CORP | 10%+ Owner · Director | 9,829,548 | 2018-07-30 | S |
| CD Holding Company, LLC | 10%+ Owner | 4,066,610 | 2026-06-17 | J |
| Straehla Arty | Director · Officer | 1,052,107 | 2023-12-18 | S |
| Layton Mark E. | Officer | 418,985 | 2023-03-03 | F |
| Palm James D | Director | 240,144 | 2024-06-12 | A |
| Lancaster Phillip | Director | 159,445 | 2026-06-26 | J |
| Booker Corey J. | Director | 140,488 | 2024-11-22 | S |
| SMITH ARTHUR L | Director | 130,034 | 2025-05-22 | S |
| Amron Holdings LLC | Director | 86,256 | 2026-06-17 | J |
| Amron Arthur H | Director | 86,256 | 2026-06-17 | J |
| YELLEN JONATHAN H | Director | 36,674 | 2019-11-18 | A |
| Jacobi Paul M. | Director | 31,067 | 2026-06-17 | J |
| LaForge Rusty Neal | Officer | 20,000 | 2018-07-30 | — |
| Ross Matthew | Director | 19,815 | 2019-11-21 | S |
| Heerwagen Paul K IV | Officer | 10,493 | 2019-06-05 | A |
| McCarthy Marc T | Director | 10,493 | 2019-06-05 | A |
| Weiss Andre | Director | 6,667 | 2016-10-19 | A |
| Gaydosik Aaron | Director | 6,667 | 2016-10-19 | A |
| Plaumann Mark Lawrence | Director | 5,000 | 2026-09-16 | P |
Recent Filings
| Date | Owner | Activity | Shares | Price | Owned After |
|---|---|---|---|---|---|
| 2026-09-16 | Plaumann Mark Lawrence | Open-market buy | 5,000 | $3.00 | 5,000 |
| 2026-06-26 | Lancaster Phillip | J | 68,152 | $0.00 | 159,445 |
| 2026-06-17 | CD Holding Company, LLC | J | 4,066,610 | $0.00 | 4,066,610 |
| 2026-06-17 | CD Holding Company, LLC | J | 2,403,831 | $0.00 | 2,403,831 |
| 2026-06-17 | DAVIDSON CHARLES E | J | 4,066,610 | $0.00 | 4,066,610 |
| 2026-06-17 | DAVIDSON CHARLES E | J | 2,403,831 | $0.00 | 2,403,831 |
| 2026-06-17 | JACOBS JOSEPH | Open-market buy | 4,019,574 | $2.60 | 10,620,789 |
| 2026-06-17 | JACOBS JOSEPH | J | 6,354,667 | $0.00 | 6,601,215 |
| 2026-06-17 | JACOBS JOSEPH | J | 1,072,896 | $0.00 | 1,451,034 |
| 2026-06-17 | DAVIDSON CHARLES E | Open-market buy | 4,019,574 | $2.60 | 10,620,789 |
| 2026-06-17 | DAVIDSON CHARLES E | J | 6,354,667 | $0.00 | 6,601,215 |
| 2026-06-17 | DAVIDSON CHARLES E | J | 1,072,896 | $0.00 | 1,451,034 |
| 2026-06-17 | Wexford GP LLC | Open-market buy | 4,019,574 | $2.60 | 10,620,789 |
| 2026-06-17 | Wexford GP LLC | J | 6,354,667 | $0.00 | 6,601,215 |
| 2026-06-17 | Wexford GP LLC | J | 1,072,896 | $0.00 | 1,451,034 |
| 2026-06-17 | WEXFORD CAPITAL LP | Open-market buy | 4,019,574 | $2.60 | 10,620,789 |
| 2026-06-17 | WEXFORD CAPITAL LP | J | 6,354,667 | $0.00 | 6,601,215 |
| 2026-06-17 | WEXFORD CAPITAL LP | J | 1,072,896 | $0.00 | 1,451,034 |
| 2026-06-17 | Amron Holdings LLC | J | 10,329 | $0.00 | 10,329 |
| 2026-06-17 | Amron Holdings LLC | J | 19,121 | $0.00 | 86,256 |
| 2026-06-17 | Amron Arthur H | J | 10,329 | $0.00 | 10,329 |
| 2026-06-17 | Amron Arthur H | J | 19,121 | $0.00 | 86,256 |
| 2026-06-17 | Jacobi Paul M. | J | 3,211 | $0.00 | 31,067 |
| 2026-06-12 | Amron Arthur H | Open-market buy | 2,000 | $3.28 | 67,135 |
| 2026-06-11 | Amron Arthur H | Open-market buy | 2,500 | $3.22 | 65,135 |
| 2026-05-28 | Amron Arthur H | Open-market buy | 3,000 | $3.25 | 62,635 |
| 2026-05-26 | Amron Arthur H | Open-market buy | 2,500 | $3.24 | 59,635 |
| 2025-12-11 | Amron Arthur H | Open-market buy | 10,000 | $1.89 | 57,135 |
| 2025-05-22 | SMITH ARTHUR L | Open-market sale | 20,000 | $2.51 | 130,034 |
| 2025-05-20 | SMITH ARTHUR L | Open-market sale | 50,000 | $2.51 | 150,034 |
| 2025-05-19 | SMITH ARTHUR L | Open-market sale | 15,000 | $2.49 | 200,034 |
| 2024-12-12 | Amron Arthur H | Open-market buy | 1,000 | $2.97 | 47,135 |
| 2024-11-25 | Booker Corey J. | Open-market sale | 15,000 | $3.47 | 125,488 |
| 2024-11-22 | Booker Corey J. | Open-market sale | 10,000 | $3.43 | 140,488 |
| 2024-11-21 | Booker Corey J. | Open-market sale | 6,709 | $3.25 | 150,488 |
| 2024-11-20 | Booker Corey J. | Open-market sale | 5,000 | $3.21 | 157,197 |
| 2024-11-14 | Booker Corey J. | Open-market sale | 3,607 | $3.50 | 162,197 |
| 2024-11-13 | Booker Corey J. | Open-market sale | 7,100 | $3.68 | 165,804 |
| 2024-11-11 | Booker Corey J. | Open-market sale | 3,494 | $3.61 | 172,904 |
| 2024-11-08 | Booker Corey J. | Open-market sale | 24 | $3.76 | 176,398 |
Source: SEC EDGAR Form 4 filings. For informational purposes only — not investment advice.