Mammoth Energy Services, Inc.
Mammoth Energy Services, Inc. (TUSK) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · TUSK · as of Sep 30, 2025
Ownership Breakdown
79
Institutional Holders
▲ 11 vs Q2
$82.58M
Total Inst. Value
▼ $19.35M vs Q2
48.17M
Shares Outstanding
freeFloat 88.50%
36.06M
13F Shares Held
▼ 340,245 vs Q2
Institutional ownership = 13F shares ÷ total outstanding. Insider % = 100 − free float. Public % = free float − institution %. Data: FMP /symbol-positions-summary + /shares-float + SEC EDGAR.
Top Institutional Holders
TUSK largest shareholders · institutional ownership
Q3 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
WEXFORD CAPITAL LP oil & gas field services, nec | 22.10M | 45.82% | 45.82% | $50.60B | Nov 14, 2025 | — held |
ADAGE CAPITAL PARTNERS GP, L.L.C. oil & gas field services, nec | 4.58M | 9.49% | 9.49% | $10.48B | Nov 14, 2025 | — held |
VALUEWORKS LLC oil & gas field services, nec | 2.04M | 4.23% | 4.23% | $4.67B | Nov 14, 2025 | ▼ 350.8K |
BLACKROCK, INC. oil & gas field services, nec | 1.45M | 3.01% | 3.01% | $3.33B | Nov 12, 2025 | ▼ 16.6K |
VANGUARD GROUP INC oil & gas field services, nec | 945.6K | 1.96% | 1.96% | $2.17B | Nov 7, 2025 | ▼ 11.6K |
DIMENSIONAL FUND ADVISORS LP oil & gas field services, nec | 936.4K | 1.94% | 1.94% | $2.14B | Nov 12, 2025 | ▼ 57.5K |
GEODE CAPITAL MANAGEMENT, LLC oil & gas field services, nec | 579.1K | 1.20% | 1.20% | $1.33B | Nov 12, 2025 | ▼ 1.6K |
STATE STREET CORP oil & gas field services, nec | 406.9K | 84.38% | 84.38% | $931.84M | Nov 14, 2025 | ▼ 1.8K |
BRIDGEWAY CAPITAL MANAGEMENT, LLC oil & gas field services, nec | 390.0K | 80.86% | 80.86% | $893.02M | Nov 14, 2025 | ▲ 39.5K |
CITADEL ADVISORS LLC oil & gas field services, nec | 268.3K | 55.64% | 55.64% | $614.44M | Nov 14, 2025 | ▲ 121.8K |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q3 2025 vs prior quarter
Q3 2025
15
Increased
+259.8K shares6
New Positions
first time holders22
Decreased
−710.2K shares0
Sold Out
fully exitedNet shares change (top 50)
450.3K
+259.8K / −710.2K
Net new holders
-1
6 new / 0 exited
Based on top 50 institutional holders by position size. Fields: isNew, isSoldOut, changeInSharesNumber (FMP extract-analytics/holder, limit=50).
Insider Buying vs Selling
TUSK insider trading · insider activity
Source: SEC Form 4
Insiders have been primarily selling shares recently. Selling may be driven by pre-scheduled Rule 10b5-1 plans rather than negative sentiment.
2
Buy transactions
0
Sell transactions
0.00
Buy/Sell ratio
$0M
Total disposed
Recent Insider Transactions
Showing 10 most recent · Common Stock only
| Name · Role | Date | Type | Shares | Price | Value | After Trans. | Filing |
|---|---|---|---|---|---|---|---|
Amron Arthur H director | May 28, 2026 | Purchase | 3,000 | $3.25 | $9.8K | 62.6K | Form 4 ↗ |
Amron Arthur H director | May 26, 2026 | Purchase | 2,500 | $3.24 | $8.1K | 59.6K | Form 4 ↗ |
Amron Arthur H director | Dec 11, 2025 | Purchase | 10,000 | $1.89 | $18.9K | 57.1K | Form 4 ↗ |
SMITH ARTHUR L director | May 22, 2025 | Sale | 20,000 | $2.51 | $50.2K | 130.0K | Form 4 ↗ |
SMITH ARTHUR L director | May 19, 2025 | Sale | 15,000 | $2.49 | $37.4K | 200.0K | Form 4 ↗ |
SMITH ARTHUR L director | May 20, 2025 | Sale | 50,000 | $2.51 | $125.5K | 150.0K | Form 4 ↗ |
Amron Arthur H director | Dec 12, 2024 | Purchase | 1,000 | $2.97 | $3.0K | 47.1K | Form 4 ↗ |
Booker Corey J. director | Nov 22, 2024 | Sale | 10,000 | $3.43 | $34.3K | 140.5K | Form 4 ↗ |
Booker Corey J. director | Nov 25, 2024 | Sale | 15,000 | $3.47 | $52.0K | 125.5K | Form 4 ↗ |
Booker Corey J. director | Nov 20, 2024 | Sale | 5,000 | $3.21 | $16.1K | 157.2K | Form 4 ↗ |
Source: /insider-trading/search (FMP stable). Buy/Sell direction: acquisitionOrDisposition A=Buy, D=Sell. RSU vesting (M-Exempt) excluded from sentiment bar. All data from SEC EDGAR public filings.
About institutional & insider ownership
Mammoth Energy Services, Inc. (TUSK) is primarily owned by institutional investors, who hold approximately 74.9% of total shares outstanding. Company insiders own approximately 11.50%, while retail and public investors account for the remaining 13.63%.
The largest institutional shareholder of Mammoth Energy Services, Inc. is WEXFORD CAPITAL LP, holding approximately 22.10 million shares — equal to 45.82% of outstanding shares — as of September 30, 2025.
A total of 79 institutional investors currently hold TUSK stock, with a combined institutional value of approximately $82,581,797 as of the most recent 13F filing period.
Frequently asked questions
TUSK ownershipMammoth Energy Services, Inc. (TUSK) is primarily owned by institutional investors, who hold approximately 74.9% of shares. The largest shareholder is WEXFORD CAPITAL LP with a 45.82% stake. Company insiders hold 11.50%. Data sourced from SEC Form 13F as of September 30, 2025.