TUSK insider buying – Mammoth Energy Services, Inc.
19 insider purchases since 2016 worth $11.4M by 10 different insiders. Last 12 months: 5 purchases, $10.5M. Most recent filing: 2026-09-17.
Small company Public float $71M (latest 10-K, SEC). Share prices of small companies usually swing much more than those of large ones, in both directions, and are easier to move with little trading.
Same time range as the chart above - each mark sits under the week of the trade. Circles = purchases (height = price paid, size = amount), red triangles = open-market sales of $50k+. Prices as reported, not adjusted for later stock splits. 8 older purchases (before the 5-year window) are listed in the table below.
Purchases are open-market buys (SEC Form 4, code "P") - insiders paying with their own money. Sales are open-market sales (code "S") of $50,000 or more; many sales are pre-planned (Rule 10b5-1) or made for taxes and diversification. Each row links to the original filing.
Bought, sold, still holding?
| Insider | Bought | First / last buy | Sold since 2016 | Holds now* | Status |
|---|---|---|---|---|---|
| Wexford GP LLC Officer | $10.7M 2× · 4,117,342 sh | 2022-06-08 2026-06-17 | 1× · $2.4M last 2016-10-19 | 18,673,038 shares as of 2026-06-22 | Holds (sold earlier) |
| SMITH ARTHUR L Director | $177,260 3× · 51,000 sh | 2017-06-09 2021-12-13 | 4× · $503,550 last 2025-05-22 | 130,034 shares as of 2025-05-27 | Sold part |
| WEXFORD CAPITAL LP Director | $145,908 2× · 81,286 sh | 2019-11-13 2022-06-16 | 2× · $115.2M last 2018-07-30 | 22,423,743 shares as of 2022-06-21 | Holds (sold earlier) |
| JACOBS JOSEPH Director | $117,331 1× · 50,802 sh | 2022-06-13 2022-06-13 | – | 22,388,743 shares as of 2022-06-15 | Holds - never sold |
| Amron Arthur H Director | $80,610 5× · 28,000 sh | 2024-03-12 2026-06-11 | – | 67,135 shares as of 2026-06-15 | Holds - never sold |
| Palm James D Director | $76,520 1× · 6,000 sh | 2017-08-24 2017-08-24 | – | 240,144 shares as of 2024-06-14 | Holds - never sold |
| Layton Mark E. CFO | $45,000 1× · 3,000 sh | 2016-10-19 2016-10-19 | 3× · $487,936 last 2022-03-10 | 418,985 shares as of 2023-03-07 | Sold part |
| Straehla Arty CEO | $29,990 2× · 1,792 sh | 2016-10-19 2017-02-28 | 5× · $3.1M last 2023-12-18 | 1,053,899 shares as of 2023-12-19 | Sold part |
| Wexford Spectrum Trading LTD Director | $22,200 1× · 16,692 sh | 2019-11-20 2019-11-20 | – | 22,045,273 shares as of 2019-11-22 | Holds - never sold |
| Plaumann Mark Lawrence Director | $15,000 1× · 5,000 sh | 2026-09-16 2026-09-16 | – | 5,000 shares as of 2026-09-17 | Holds - never sold |
* Shares held after the insider's most recent SEC filing for this company (all share classes, direct and indirect). If an insider stops filing, later changes are not known.
Insider buying and selling by year
| Year | Purchases | Bought | Buyers | Sales | Sold |
|---|---|---|---|---|---|
| 2026 | 4 | $10.5M | 3 | – | – |
| 2025 | 1 | $18,900 | 1 | 2 | $213,050 |
| 2024 | 2 | $29,250 | 1 | 1 | $86,350 |
| 2023 | 0 | – | – | 2 | $833,750 |
| 2022 | 3 | $456,089 | 3 | 2 | $223,851 |
| 2021 | 1 | $50,000 | 1 | 2 | $1.1M |
| 2020 | 1 | $25,800 | 1 | – | – |
| 2019 | 2 | $71,029 | 2 | – | – |
| 2018 | 0 | – | – | 7 | $168.0M |
| 2017 | 3 | $187,990 | 3 | 1 | $476,706 |
| 2016 | 2 | $64,980 | 2 | 2 | $3.5M |
Insider purchases
| Filed | Insider | Role | Shares | Avg price | Value | Holdings | Filing |
|---|---|---|---|---|---|---|---|
| 2026-09-17 | Plaumann Mark Lawrence | Director | 5,000 | $3.00 | $15,000 | SEC | |
| 2026-06-22 | Wexford GP LLC | Officer | 4,019,574 | $2.60 | $10.5M | +60.9% | SEC |
| 2026-06-15 | Amron Arthur H | Director | 4,500 | $3.25 | $14,610 | +7.2% | SEC |
| 2026-05-28 | Amron Arthur H | Director | 5,500 | $3.25 | $17,850 | +9.6% | SEC |
| 2025-12-15 | Amron Arthur H | Director | 10,000 | $1.89 | $18,900 | +21.2% | SEC |
| 2024-05-30 | Amron Arthur H | Director | 5,000 | $3.62 | $18,090 | +37.7% | SEC |
| 2024-03-14 | Amron Arthur H | Director | 3,000 | $3.72 | $11,160 | +29.2% | SEC |
| 2022-06-21 | WEXFORD CAPITAL LP | Director | 45,382 | $2.14 | $97,079 | +0.2% | SEC |
| 2022-06-15 | JACOBS JOSEPH | Director | 50,802 | $2.31 | $117,331 | +0.2% | SEC |
| 2022-06-10 | Wexford GP LLC | Director | 97,768 | $2.47 | $241,679 | +0.4% | SEC |
| 2021-12-14 | SMITH ARTHUR L | Director | 25,000 | $2.00 | $50,000 | +16.1% | SEC |
| 2020-09-08 | SMITH ARTHUR L | Director | 20,000 | $1.29 | $25,800 | +18.2% | SEC |
| 2019-11-22 | Wexford Spectrum Trading LTD | Director | 16,692 | $1.33 | $22,200 | +0.1% | SEC |
| 2019-11-15 | WEXFORD CAPITAL LP | Director | 35,904 | $1.36 | $48,829 | +0.2% | SEC |
| 2017-08-28 | Palm James D | Director | 6,000 | $12.75 | $76,520 | +89.6% | SEC |
| 2017-06-13 | SMITH ARTHUR L | Director | 6,000 | $16.91 | $101,460 | SEC | |
| 2017-03-02 | Straehla Arty | CEO | 460 | $21.76 | $10,010 | SEC | |
| 2016-10-21 | Straehla Arty | CEO | 1,332 | $15.00 | $19,980 | SEC | |
| 2016-10-21 | Layton Mark E. | CFO | 3,000 | $15.00 | $45,000 | SEC |
Insider sales
| Filed | Insider | Role | Shares | Avg price | Value | Type | Filing |
|---|---|---|---|---|---|---|---|
| 2025-05-27 | SMITH ARTHUR L | Director | 20,000 | $2.51 | $50,200 | Sale | SEC |
| 2025-05-21 | SMITH ARTHUR L | Director | 65,000 | $2.51 | $162,850 | Sale | SEC |
| 2024-11-26 | Booker Corey J. | Director | 25,000 | $3.45 | $86,350 | Sale | SEC |
| 2023-12-19 | Straehla Arty | CEO | 70,000 | $4.36 | $305,400 | Sale | SEC |
| 2023-12-15 | Straehla Arty | CEO | 120,000 | $4.40 | $528,350 | Sale | SEC |
| 2022-11-14 | SMITH ARTHUR L | Director | 20,000 | $7.07 | $141,400 | Sale | SEC |
| 2022-03-11 | Layton Mark E. | CFO | 40,417 | $2.04 | $82,451 | Sale | SEC |
| 2021-03-11 | Layton Mark E. | CFO | 55,789 | $5.22 | $291,219 | Sale | SEC |
| 2021-03-11 | Straehla Arty | CEO | 148,990 | $5.35 | $796,537 | Sale | SEC |
| 2018-12-06 | SMITH ARTHUR L | Director | 6,000 | $24.85 | $149,100 | Sale | SEC |
| 2018-11-13 | Straehla Arty | CEO | 38,841 | $26.68 | $1.0M | Sale | SEC |
| 2018-08-01 | WEXFORD CAPITAL LP | Director | 266,026 | $38.01 | $10.1M | Sale | SEC |
| 2018-08-01 | GULFPORT ENERGY CORP | Director | 118,974 | $38.01 | $4.5M | Sale | SEC |
| 2018-07-03 | WEXFORD CAPITAL LP | Director | 2,764,400 | $38.01 | $105.1M | Sale | SEC |
| 2018-07-03 | GULFPORT ENERGY CORP | Director | 1,235,600 | $38.01 | $47.0M | Sale | SEC |
Showing the latest 15 of 19 sales of $50,000+ since 2016.
Compiled automatically from public SEC filings. Not investment advice. Get every new insider purchase in the daily report.
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