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Mammoth Energy Services, Inc. (TUSK) institutional ownership

Market cap$144M SectorIndustrials
Funds holding · Q1 2026
86
reported TUSK position changes
Top owners · Q1 2026
No disclosed owners are available.
Institutional activity · Q1 2026
Activity unavailable N/A
51 buyers · 35 sellers

Mammoth Energy Services, Inc. (TUSK) price and institutional activity

Dates

Q1 2026

$0 bought by 51 investors
Peapod Lane Capital LLCLos Angeles Capital Management LLC +49 more
$0 sold by 35 investors
Russell Investments Group, Ltd.JPMorgan Chase & Co +33 more
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Bought Sold Totals per quarter; hover a bar for the names.

Mammoth Energy Services, Inc. (TUSK) institutional activity · 86

Investor Type Est. change Change Δ Own Date
Peapod Lane Capital LLC · New
Change +600K Date Q1 2026
Peapod Lane Capital LLC New· Q1 2026 +600K Q1 2026
Russell Investments Group, Ltd. · Reduced
Change −179K Date Q1 2026
Russell Investments Group, Ltd. Reduced· Q1 2026 −179K Q1 2026
Los Angeles Capital Management LLC · New
Change +163K Date Q1 2026
Los Angeles Capital Management LLC New· Q1 2026 +163K Q1 2026
JPMorgan Chase & Co · Reduced
Change −156K Date Q1 2026
JPMorgan Chase & Co Reduced· Q1 2026 −156K Q1 2026
Boston Partners · New
Change +154K Date Q1 2026
Boston Partners New· Q1 2026 +154K Q1 2026
Morgan Stanley · Reduced
Change −140K Date Q1 2026
Morgan Stanley Reduced· Q1 2026 −140K Q1 2026
Goldman Sachs Group Inc · Added
Change +134K Date Q1 2026
Goldman Sachs Group Inc Added· Q1 2026 +134K Q1 2026
Vanguard · Added
Change +116K Date Q1 2026
Vanguard Added· Q1 2026 +116K Q1 2026
Citadel Advisors LLC Added· Q1 2026 +111K +50.5% Q1 2026
Corient Private Wealth LLC · Exited
Change −98K Δ Own −100.0% Date Q1 2026
Corient Private Wealth LLC Exited· Q1 2026 −98K −100.0% Q1 2026
Acadian Asset Management LLC · Added
Change +97K Date Q1 2026
Acadian Asset Management LLC Added· Q1 2026 +97K Q1 2026
Bridgeway Capital Management, LLC · Reduced
Change −78K Date Q1 2026
Bridgeway Capital Management, LLC Reduced· Q1 2026 −78K Q1 2026
Landscape Capital Management, L.L.C. · Exited
Change −73K Δ Own −100.0% Date Q1 2026
Landscape Capital Management, L.L.C. Exited· Q1 2026 −73K −100.0% Q1 2026
Centiva Capital, LP · Added
Change +70K Date Q1 2026
Centiva Capital, LP Added· Q1 2026 +70K Q1 2026
Quadrature Capital Ltd · Exited
Change −66K Δ Own −100.0% Date Q1 2026
Quadrature Capital Ltd Exited· Q1 2026 −66K −100.0% Q1 2026
Data through Q1 2026 · filed Jun 2, 2026
15 of 86

Famous investor activity in Mammoth Energy Services, Inc. (TUSK)

Mammoth Energy Services, Inc. (TUSK) insider trading

Company insiders, action and economics first; trade and filed dates last.
Dates
Insider Title Type Price Qty Value Owned ΔOwn Trade date Filed date
Lancaster Phillip · Director Other Form 4 events 68K
Owned 159K ΔOwn +74.7% Trade date Jun 26, 2026 Filed date Jul 1, 2026
Lancaster Phillip Director Other Form 4 events 68K 159K +74.7% Jun 26, 2026 Jul 1, 2026
Jacobi Paul M. · Director Other Form 4 events 3K
Owned 31K ΔOwn +11.5% Trade date Jun 17, 2026 Filed date Jun 22, 2026
Jacobi Paul M. Director Other Form 4 events 3K 31K +11.5% Jun 17, 2026 Jun 22, 2026
Amron Arthur H. · Director 2 operations 29K
Owned 10K Trade date Jun 17, 2026 Filed date Jun 22, 2026
Amron Arthur H. Director 2 operations 29K 10K Jun 17, 2026 Jun 22, 2026
Wexford Capital LP · Director Buy +$10M
Price $2.60 Qty +4.0M Owned 10.6M ΔOwn +60.9% Trade date Jun 17, 2026 Filed date Jun 22, 2026
Wexford Capital LP Director Buy $2.60 +4.0M +$10M 10.6M +60.9% Jun 17, 2026 Jun 22, 2026
Wexford Capital LP · Director 2 operations 7.4M
Owned 6.6M Trade date Jun 17, 2026 Filed date Jun 22, 2026
Wexford Capital LP Director 2 operations 7.4M 6.6M Jun 17, 2026 Jun 22, 2026
Davidson Charles E. · 10% Owner 2 operations 6.5M
Owned 4.1M Trade date Jun 17, 2026 Filed date Jun 22, 2026
Davidson Charles E. 10% Owner 2 operations 6.5M 4.1M Jun 17, 2026 Jun 22, 2026
Amron Arthur H. · Director Buy +$7K
Price $3.28 Qty +2K Owned 67K Trade date Jun 12, 2026 Filed date Jun 15, 2026
Amron Arthur H. Director Buy $3.28 +2K +$7K 67K Jun 12, 2026 Jun 15, 2026
Amron Arthur H. · Director Buy +$8K
Price $3.22 Qty +2K Owned 65K Trade date Jun 11, 2026 Filed date Jun 15, 2026
Amron Arthur H. Director Buy $3.22 +2K +$8K 65K Jun 11, 2026 Jun 15, 2026
Amron Arthur H. · Director Buy +$10K
Price $3.25 Qty +3K Owned 63K Trade date May 28, 2026 Filed date May 28, 2026
Amron Arthur H. Director Buy $3.25 +3K +$10K 63K May 28, 2026 May 28, 2026
Amron Arthur H. · Director Buy +$8K
Price $3.24 Qty +2K Owned 60K Trade date May 26, 2026 Filed date May 28, 2026
Amron Arthur H. Director Buy $3.24 +2K +$8K 60K May 26, 2026 May 28, 2026
Amron Arthur H. · Director Buy +$19K
Price $1.89 Qty +10K Owned 57K Trade date Dec 11, 2025 Filed date Dec 15, 2025
Amron Arthur H. Director Buy $1.89 +10K +$19K 57K Dec 11, 2025 Dec 15, 2025
11 of 11

Mammoth Energy Services, Inc. (TUSK) activist and large shareholders

What are Schedules 13D and 13G?

Dates
Owner/Filer identity Shares reported % of shares outstanding Filing date
Wexford Capital LP 12.1M
% of shares outstanding 25.1% Filing date Jun 22, 2026
Wexford Capital LP 12.1M 25.1% Jun 22, 2026
Charles E. Davidson 6.5M
% of shares outstanding 13.4% Filing date Jun 22, 2026
Charles E. Davidson 6.5M 13.4% Jun 22, 2026
Adage Capital Partners Gp, L.L.C. 3.1M
% of shares outstanding 6.6% Filing date Feb 9, 2023
Adage Capital Partners Gp, L.L.C. 3.1M 6.6% Feb 9, 2023
Valueworks Limited Partners, LP 1.9M
% of shares outstanding 3.9% Filing date Aug 14, 2025
Valueworks Limited Partners, LP 1.9M 3.9% Aug 14, 2025
4 of 4

Mammoth Energy Services, Inc. (TUSK) ownership FAQ

Who owns TUSK?

86 reporting institutions disclosed TUSK position changes in the Q1 2026 snapshot.

How is institutional activity calculated?

For each manager, WhoBought compares accepted consecutive 13F share counts. Share change is current shares minus prior shares. Estimated dollar change is that signed share change multiplied by the split-adjusted quarter-mean close. The activity table on this page uses Q1 2026.

What are activist and large shareholder filings?

An investor crossing 5% of a share class generally files Schedule 13D for activist intent or Schedule 13G for a passive position. The technical form names appear here rather than in the activity rows.

Where does this data come from?

Ownership and institutional activity come from SEC Form 13F filings. Insider activity comes from SEC Form 4, and large-shareholder activity from SEC Schedules 13D and 13G. FMP supplies price data only. Company logos use the local verified Parqet cache with one shared fallback.

Why are ownership reports delayed?

Form 13F is a quarterly disclosure and is normally filed after the quarter ends. Every ownership and activity value therefore names its represented period; it is not presented as a live position.

How are missing table values shown?

A muted dash marks a missing table value. It means the filing omitted the value, comparable data is unavailable, or no prior position exists for comparison.