TUSK · Mammoth Energy Services, Inc. · Shareholders & Ownership

$2.75 +0.06 (+2.04%)

Market Cap

$131.63M

48.13M

Volume · Oct 21 12.7K Avg daily vol (3M) 143.22K

Every disclosed holder of TUSK in one list: 13F institutions, Schedule 13D and 13G filers, insiders (Forms 3, 4 and 5) and registered funds, each from its own latest filing. Holders nest by CIK and SEC reporting links, never by name, and each is summed once.

How the holder list picks a filing →

Who Owns TUSK

13F quarter Sep 30, 2026, combined view: filers that have not filed yet carry their Jun 30, 2026 positions

Holder group	Holders	Shares	% Out	Summed
Institutional (13F)	88	25,881,712	53.78%	Yes
Insiders (Forms 3, 4, 5)	7	7,018,060	14.58%	Yes
13D/G-only blocks	1	2,389,031	4.96%	Yes
Remaining	—	12,838,782	26.68%	Rest
Registered funds (N-PORT, not summed)	54	2,846,685	5.91%	No

Shares outstanding: 48,127,585, the issuer's latest cover-page count restated onto today's split basis.

13D/G-only counts each filer's latest 13D or 13G that no 13F report of the listing contains, that names no 13F filer and that no counted insider files. Funds are never summed: their shares sit inside their advisers' 13F reports.

Holders of TUSK

One row per holder Every filing By ultimate parent

All 13F Funds Insiders 13D/G Non-US

#	Holder	Shares	% Out	Change	As of	Notes
1	WEXFORD CAPITAL LP 13F CIK 1048462 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	12,071,823	25.08%	-9,996,389	Jun 30, 2026	carried, not yet filed for the newest quarter
1.1	WEXFORD CAPITAL LP Insider CIK 1048462 · Jun 17, 2026 10% Owner, issuer-wide, not summed	12,071,823	25.08%	-9,959,049	Jun 17, 2026	10% Owner, issuer-wide, not summed
2	Charles E. Davidson 13G CIK 1001391 · Unknown · Jun 17, 2026 Rule 13d-1(c), passive investor, not summed	6,470,441	13.44%	—	Jun 17, 2026	Rule 13d-1(c), passive investor, not summed
2.1	DAVIDSON CHARLES E Insider CIK 1001391 · Jun 17, 2026 10% Owner, issuer-wide	6,470,441	13.44%	—	Jun 17, 2026	10% Owner, issuer-wide
3	ADAGE CAPITAL PARTNERS GP, L.L.C. 13F CIK 1165408 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	4,575,000	9.51%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
4	VALUEWORKS LLC 13G CIK 1282189 · Registered investment adviser · Jun 30, 2025 Rule 13d-1(c), passive investor	2,389,031	4.96%	-747,340	Jun 30, 2025	Rule 13d-1(c), passive investor
5	VANGUARD CAPITAL MANAGEMENT LLC 13F CIK 2100119 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	1,059,603	2.20%	+240,483	Jun 30, 2026	carried, not yet filed for the newest quarter
6	Peapod Lane Capital LLC 13F CIK 2050979 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	807,804	1.68%	+207,999	Jun 30, 2026	carried, not yet filed for the newest quarter
7	VANGUARD TOTAL STOCK MARKET INDEX FUND Fund S000002848 · Registered fund · Jun 30, 2026 VANGUARD INDEX FUNDS, not summed	767,902	1.60%	+234,210	Jun 30, 2026	VANGUARD INDEX FUNDS, not summed
8	DIMENSIONAL FUND ADVISORS LP 13F CIK 354204 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	691,667	1.44%	+5,468	Jun 30, 2026	carried, not yet filed for the newest quarter
8.1	U.S. SMALL CAP PORTFOLIO Fund S000000971 · Registered fund · Jul 31, 2026 DFA INVESTMENT DIMENSIONS GROUP INC, not summed	156,438	0.33%	0	Jul 31, 2026	DFA INVESTMENT DIMENSIONS GROUP INC, not summed
8.2	Dimensional U.S. Small Cap ETF Fund S000070906 · Registered fund · Jul 31, 2026 Dimensional ETF Trust, not summed	154,800	0.32%	-6,100	Jul 31, 2026	Dimensional ETF Trust, not summed
8.3	U.S. MICRO CAP PORTFOLIO Fund S000000948 · Registered fund · Jul 31, 2026 DFA INVESTMENT DIMENSIONS GROUP INC, not summed	84,048	0.17%	+11,899	Jul 31, 2026	DFA INVESTMENT DIMENSIONS GROUP INC, not summed
8.4	U.S. SMALL CAP VALUE PORTFOLIO Fund S000000987 · Registered fund · Jul 31, 2026 DFA INVESTMENT DIMENSIONS GROUP INC, not summed	37,940	0.08%	0	Jul 31, 2026	DFA INVESTMENT DIMENSIONS GROUP INC, not summed
8.5	Dimensional U.S. Core Equity 2 ETF Fund S000070903 · Registered fund · Jul 31, 2026 Dimensional ETF Trust, not summed	25,346	0.05%	0	Jul 31, 2026	Dimensional ETF Trust, not summed
9	JANE STREET GROUP, LLC 13F CIK 1595888 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	506,662	1.05%	+483,808	Jun 30, 2026	carried, not yet filed for the newest quarter
10	CITADEL ADVISORS LLC 13F CIK 1423053 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	452,163	0.94%	+120,796	Jun 30, 2026	carried, not yet filed for the newest quarter
11	BlackRock, Inc. 13F CIK 2012383 · Holding company · Jun 30, 2026 carried, not yet filed for the newest quarter	407,976	0.85%	-1,046,863	Jun 30, 2026	carried, not yet filed for the newest quarter
11.1	iShares Micro-Cap ETF Fund S000004439 · Registered fund · Jun 30, 2026 iShares Trust, not summed	86,748	0.18%	+27,919	Jun 30, 2026	iShares Trust, not summed
12	MARSHALL WACE, LLP 13F CIK 1318757 · Exempt reporting adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	395,583	0.82%	+395,583	Jun 30, 2026	carried, not yet filed for the newest quarter
13	Johns Hopkins University 13F CIK 1764756 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	387,359	0.80%	+387,359	Jun 30, 2026	carried, not yet filed for the newest quarter
14	BRIDGEWAY CAPITAL MANAGEMENT, LLC 13F CIK 1107261 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	332,313	0.69%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
14.1	Ultra-Small Company Market Fund Fund S000004424 · Registered fund · Jun 30, 2026 Bridgeway Funds, Inc., not summed	60,000	0.12%	0	Jun 30, 2026	Bridgeway Funds, Inc., not summed
14.2	Omni Small-Cap Value Fund Fund S000033567 · Registered fund · Jun 30, 2026 Bridgeway Funds, Inc., not summed	21,500	0.04%	0	Jun 30, 2026	Bridgeway Funds, Inc., not summed
15	Russell Investments Group, Ltd. 13F CIK 1692234 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	329,821	0.69%	+261,791	Jun 30, 2026	carried, not yet filed for the newest quarter
15.1	U.S. Small Cap Equity Fund Fund S000001586 · Registered fund · Jul 31, 2026 RUSSELL INVESTMENT CO, not summed	139,495	0.29%	+31,082	Jul 31, 2026	RUSSELL INVESTMENT CO, not summed
15.2	Tax-Managed U.S. Mid & Small Cap Fund Fund S000001571 · Registered fund · Jul 31, 2026 RUSSELL INVESTMENT CO, not summed	54,843	0.11%	0	Jul 31, 2026	RUSSELL INVESTMENT CO, not summed
15.3	U.S. Small Cap Equity Fund Fund S000006864 · Registered fund · Jun 30, 2026 RUSSELL INVESTMENT FUNDS, not summed	25,408	0.05%	—	Jun 30, 2026	RUSSELL INVESTMENT FUNDS, not summed
16	GEODE CAPITAL MANAGEMENT, LLC 13F CIK 1214717 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	306,028	0.64%	-304,898	Jun 30, 2026	carried, not yet filed for the newest quarter
17	RENAISSANCE TECHNOLOGIES LLC 13F CIK 1037389 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	292,280	0.61%	+60,308	Jun 30, 2026	carried, not yet filed for the newest quarter
18	ARROWSTREET CAPITAL, LIMITED PARTNERSHIP 13F CIK 1164508 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	290,096	0.60%	+290,096	Jun 30, 2026	carried, not yet filed for the newest quarter
19	VANGUARD EXTENDED MARKET INDEX FUND Fund S000002841 · Registered fund · Jun 30, 2026 VANGUARD INDEX FUNDS, not summed	270,943	0.56%	-1,013	Jun 30, 2026	VANGUARD INDEX FUNDS, not summed
20	Empowered Funds, LLC 13F CIK 1592828 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	241,313	0.50%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
20.1	EA Bridgeway Omni Small-Cap Value ETF Fund S000078089 · Registered fund · Jun 30, 2026 EA Series Trust, not summed	241,313	0.50%	0	Jun 30, 2026	EA Series Trust, not summed
21	AQR CAPITAL MANAGEMENT LLC 13F CIK 1167557 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	177,824	0.37%	+111,093	Jun 30, 2026	carried, not yet filed for the newest quarter
22	VANGUARD FIDUCIARY TRUST CO 13F CIK 933478 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	161,791	0.34%	-8,340	Jun 30, 2026	carried, not yet filed for the newest quarter
23	Lancaster Phillip Insider CIK 1336012 · Jun 26, 2026 Director, issuer-wide	159,445	0.33%	—	Jun 26, 2026	Director, issuer-wide
24	Round Rock Advisors LLC 13F CIK 1846991 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	152,841	0.32%	+152,841	Jun 30, 2026	carried, not yet filed for the newest quarter
25	MORGAN STANLEY 13F CIK 895421 · Holding company · Jun 30, 2026 carried, not yet filed for the newest quarter	133,560	0.28%	-19,163	Jun 30, 2026	carried, not yet filed for the newest quarter
26	Centiva Capital, LP 13F CIK 1692507 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	130,870	0.27%	+19,762	Jun 30, 2026	carried, not yet filed for the newest quarter
27	SMITH ARTHUR L Insider CIK 1034323 · May 22, 2025 Director, issuer-wide	130,034	0.27%	-20,000	May 22, 2025	Director, issuer-wide
28	GSA CAPITAL PARTNERS LLP 13F CIK 1362033 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	129,547	0.27%	+115,638	Jun 30, 2026	carried, not yet filed for the newest quarter
29	Booker Corey J. Insider CIK 1821262 · Nov 25, 2024 Director, issuer-wide	125,488	0.26%	-25,000	Nov 25, 2024	Director, issuer-wide
30	MILLENNIUM MANAGEMENT LLC 13F CIK 1273087 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	124,186	0.26%	+124,186	Jun 30, 2026	carried, not yet filed for the newest quarter
31	VANGUARD RUSSELL 2000 INDEX FUND Fund S000030003 · Registered fund · May 31, 2026 VANGUARD SCOTTSDALE FUNDS, not summed	123,590	0.26%	+4,830	May 31, 2026	VANGUARD SCOTTSDALE FUNDS, not summed
32	ACADIAN ASSET MANAGEMENT LLC 13F CIK 916542 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	122,050	0.25%	-82,055	Jun 30, 2026	carried, not yet filed for the newest quarter
33	STIFEL FINANCIAL CORP 13F CIK 720672 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	105,572	0.22%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
34	STATE STREET CORP 13F CIK 93751 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	101,864	0.21%	-320,058	Jun 30, 2026	carried, not yet filed for the newest quarter
35	BANK OF AMERICA CORP /DE/ 13F CIK 70858 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	97,046	0.20%	+71,457	Jun 30, 2026	carried, not yet filed for the newest quarter
36	Amron Arthur H Insider CIK 1179697 · Jun 17, 2026 Director, issuer-wide	96,585	0.20%	+29,450	Jun 17, 2026	Director, issuer-wide
37	BNP PARIBAS ARBITRAGE, SA 13F CIK 1166588 · Non-US institution · Jun 30, 2026 carried, not yet filed for the newest quarter	92,964	0.19%	+76,217	Jun 30, 2026	carried, not yet filed for the newest quarter
38	Dunham Small Cap Value Fund Fund S000020974 · Registered fund · Jul 31, 2026 Dunham Funds, not summed	91,271	0.19%	+19,256	Jul 31, 2026	Dunham Funds, not summed
39	Point72 Asset Management, L.P. 13F CIK 1603466 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	72,091	0.15%	+72,091	Jun 30, 2026	carried, not yet filed for the newest quarter
40	Boston Partners 13F CIK 1386060 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	68,935	0.14%	-85,453	Jun 30, 2026	carried, not yet filed for the newest quarter
41	Aster Capital Management (DIFC) Ltd 13F CIK 2040915 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	67,570	0.14%	+67,570	Jun 30, 2026	carried, not yet filed for the newest quarter
42	Bank of New York Mellon Corp 13F CIK 1390777 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	62,007	0.13%	-70,532	Jun 30, 2026	carried, not yet filed for the newest quarter
43	Qube Research & Technologies Ltd 13F CIK 1729829 · Exempt reporting adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	58,859	0.12%	+58,859	Jun 30, 2026	carried, not yet filed for the newest quarter
44	TWO SIGMA INVESTMENTS, LP 13F CIK 1179392 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	58,538	0.12%	+58,538	Jun 30, 2026	carried, not yet filed for the newest quarter
45	NORTHERN TRUST CORP 13F CIK 73124 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	57,180	0.12%	-129,948	Jun 30, 2026	carried, not yet filed for the newest quarter
46	GOLDMAN SACHS GROUP INC 13F CIK 886982 · Holding company · Jun 30, 2026 carried, not yet filed for the newest quarter	54,928	0.11%	-168,561	Jun 30, 2026	carried, not yet filed for the newest quarter
47	SUSQUEHANNA INTERNATIONAL GROUP, LLP 13F CIK 1446194 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	49,920	0.10%	+13,621	Jun 30, 2026	carried, not yet filed for the newest quarter
48	XTX Topco Ltd 13F CIK 1828301 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	49,261	0.10%	+49,261	Jun 30, 2026	carried, not yet filed for the newest quarter
49	Walleye Capital LLC 13F CIK 1758720 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	49,141	0.10%	+49,141	Jun 30, 2026	carried, not yet filed for the newest quarter
50	WELLINGTON MANAGEMENT GROUP LLP 13F CIK 902219 · Holding company · Jun 30, 2026 carried, not yet filed for the newest quarter	47,486	0.10%	-20,929	Jun 30, 2026	carried, not yet filed for the newest quarter

8 more nested rows are not shown here; Every filing lists them all.

Shares are restated onto today's split basis. Change compares each row with the same holder's previous filing in the same source; a dash means there is none to compare. Nested 13D/G, insider and fund rows are not summed, since a 13F report already holds them.

Showing 1–50 of 124 holders

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Key facts CIK 1679268 CUSIP 56155L108 13F (30d) 4 filings 4 filers Visit website Investor relations