Stock Trading Canary

United States · SEC Form 4 · Snapshot date: 2026-10-18 · Built: 2026-10-18 · 中文

← United States · Coverage record

US · SEC FORM 4

MAMMOTH ENERGY SERVICES, INC.

TUSK · Nasdaq · CIK 0001679268 · Industrials · Conglomerates

INSIDER SIGNAL

77.8 / 100

3 buyers · 6 purchase transaction lines · $10.5M gross purchase

WHY THIS SIGNAL?

Buyer breadthModerate
Purchase sizeStrong
RoleStrong
RecencyModerate
ConvictionStrong
Score anatomy

Each bar shows the contribution to the current score; the weights and formula stay unchanged.

Cluster+21.0 / 35
Purchase size+22.9 / 25
Role+18.0 / 20
Recency+5.9 / 10
Conviction+10.0 / 10

What is holding the score back?

  • ⚠ Cluster breadth is moderate · 3 insider(s), not 4+
  • ✓ Role scores high · most senior buyer: Chief Business Officer

Purchase-size comments are relative to the model scale. Average daily volume is a separate market-context diagnostic.

US-v1.2 ranks qualifying equity purchases under the current 180-day rules. The score is a research priority, not a return forecast or probability. Backtests have not shown that a higher US score is followed by better returns.

Insider activity timeline

Owner lanes show the latest 180 days. Symbol shape identifies the transaction type; sales remain context only.

AprMayJunJulAugSepOct
Amron Arthur HDirector
●●●●
DAVIDSON CHARLES E; JACOBS JOSEPH; WEXFORD CAPITAL LP; Wexford GP LLCChief Business Officer
○●
Jacobi Paul M.Chief Business Officer
○
Amron Arthur H; Amron Holdings LLCDirector
○
CD Holding Company, LLC; DAVIDSON CHARLES ETenPercentOwner
○
Plaumann Mark LawrenceDirector
●
● Purchase▼ Sale○ Other

Showing the six most active owners; 1 additional owner(s) remain in Form 4 evidence.

Purchase breadth & concentration

QUALIFYING BUYERS3
PURCHASE CONCENTRATION100%Largest buyer: DAVIDSON CHARLES E; JACOBS JOSEPH; WEXFORD CAPITAL LP; Wexford GP LLC · $10.5M
CLUSTER BUYING · 15D2 insidersPeak activity: 2026-06-11–2026-06-17

Roles in the peak window: Chief Business Officer, Director. Concentration uses priced qualifying P lines only and does not change the saved score.

SIGNAL HISTORY

77.8 / 100

Latest recorded score

↓ -0.2 ptsversus the previous recorded snapshot
  1. 78.4
  2. 78.3
  3. 78.2
  4. 78.0
  5. 77.8

Only scores saved when a full US scoring run completed are shown; gaps are not reconstructed.

Recent Form 4 activity

7Purchases
0Sales
8Other Form 4 lines
9SEC filings · 365 days
BUYING6 qualifying P line(s) · 180 days
SELLING0 sale line(s) · context only
OTHER8 exercise / withholding / award / gift / other lines
10b5-1 / PLANNEDNot assessed

P is an open-market or private purchase. S is a sale. M, F, A and G usually describe exercises, tax withholding, awards and gifts. These categories remain visually separate.

Market context

Market context provides additional background on recent price performance and risk. It does not affect the Insider Signal.

Price performance

1M
-9.3%
3M
-3.1%
6M
+17.0%
12M
+21.0%

Volatility & liquidity

Volatility
67.0%
Beta
—
Avg daily value
USD 431,321

Valuation

Market cap
USD 135.7M
P/E
29.5×

Fundamentals

Profit margin
10.4%
ROE
1.8%
Industry
Conglomerates

Market data

Price data up to: 2026-10-11 · Price source: OpenBB/yfinance; volume from price cache (yfinance) · From SEC filings: Market cap, P/E, Profit margin, ROE · Fiscal year ended: 2025-12-31 · Market cap is the shares outstanding stated on the filing cover multiplied by the latest close. Share count date: 2026-08-04 · Status: PASS

Short interest

Short interest is external context reported to FINRA by broker-dealers. It does not affect the Insider Signal.

Shares short
110,518
Previous report
88,848
Avg daily volume
93,678
Days to cover
1.2

FINRA settlement date: 2026-09-30 · Captured 2026-10-12 · FINRA equity short interest ↗. A share count, published about a week after each of two settlement dates a month; not a percentage of shares outstanding.

Historical equity purchases

Qualifying code P transactions in the local Form 4 history, including purchases outside the current signal window.

Transaction dateReporting ownerTypeSecuritySharesAvg. priceApprox. valueSource
2026-09-16Plaumann Mark LawrencePurchase (P)Common Stock5,000USD 3.00USD 15,000SEC filing ↗
2026-06-17DAVIDSON CHARLES E; JACOBS JOSEPH; WEXFORD CAPITAL LP; Wexford GP LLCPurchase (P)Common Stock4,019,574USD 2.60USD 10,450,892SEC filing ↗
2026-06-12Amron Arthur HPurchase (P)Common Stock2,000USD 3.28USD 6,560SEC filing ↗
2026-06-11Amron Arthur HPurchase (P)Common Stock2,500USD 3.22USD 8,050SEC filing ↗
2026-05-28Amron Arthur HPurchase (P)Common Stock3,000USD 3.25USD 9,750SEC filing ↗
2026-05-26Amron Arthur HPurchase (P)Common Stock2,500USD 3.24USD 8,100SEC filing ↗
2025-12-11Amron Arthur HPurchase (P)Common Stock10,000USD 1.89USD 18,900SEC filing ↗
2024-12-12Amron Arthur HPurchase (P)Common Stock1,000USD 2.97USD 2,970SEC filing ↗
2024-05-30Amron Arthur HPurchase (P)Common Stock3,000USD 3.65USD 10,950SEC filing ↗
2024-05-28Amron Arthur HPurchase (P)Common Stock2,000USD 3.57USD 7,140SEC filing ↗
2024-03-12Amron Arthur HPurchase (P)Common Stock3,000USD 3.72USD 11,160SEC filing ↗
2022-06-17DAVIDSON CHARLES E; JACOBS JOSEPH; WEXFORD CAPITAL LP; Wexford GP LLCPurchase (P)Common Stock10,382USD 2.17USD 22,529SEC filing ↗
2022-06-16DAVIDSON CHARLES E; JACOBS JOSEPH; WEXFORD CAPITAL LP; Wexford GP LLCPurchase (P)Common Stock35,000USD 2.13USD 74,550SEC filing ↗
2022-06-15DAVIDSON CHARLES E; JACOBS JOSEPH; WEXFORD CAPITAL LP; Wexford GP LLCPurchase (P)Common Stock5,100USD 2.23USD 11,373SEC filing ↗
2022-06-14DAVIDSON CHARLES E; JACOBS JOSEPH; WEXFORD CAPITAL LP; Wexford GP LLCPurchase (P)Common Stock20,600USD 2.28USD 46,968SEC filing ↗

Form 4 evidence

15 transaction lines in the latest 365-day window; 84 in local history.

DateOwnerTypeSecuritySharesAvg. priceApprox. valueSource
2026-09-16Plaumann Mark LawrencePurchase (P)Common Stock5,000USD 3.00USD 15,000SEC filing ↗
2026-06-26Lancaster PhillipJ (J)Common Stock68,152USD 0.00USD 0SEC filing ↗
2026-06-17Jacobi Paul M.J (J)Common Stock3,211USD 0.00USD 0SEC filing ↗
Show recent Form 4 evidence (12 grouped rows)
DateOwnerTypeSecuritySharesAvg. priceApprox. valueSource
2026-09-16Plaumann Mark LawrencePurchase (P)Common Stock5,000USD 3.00USD 15,000SEC filing ↗
2026-06-26Lancaster PhillipJ (J)Common Stock68,152USD 0.00USD 0SEC filing ↗
2026-06-17Jacobi Paul M.J (J)Common Stock3,211USD 0.00USD 0SEC filing ↗
2026-06-17DAVIDSON CHARLES E; JACOBS JOSEPH; WEXFORD CAPITAL LP; Wexford GP LLCPurchase (P)Common Stock4,019,574USD 2.60USD 10,450,892SEC filing ↗
2026-06-17DAVIDSON CHARLES E; JACOBS JOSEPH; WEXFORD CAPITAL LP; Wexford GP LLCJ (J)Common Stock7,427,563USD 0.00USD 0SEC filing ↗
2026-06-17CD Holding Company, LLC; DAVIDSON CHARLES EJ (J)Common Stock6,470,441USD 0.00USD 0SEC filing ↗
2026-06-17Amron Arthur H; Amron Holdings LLCJ (J)Common Stock29,450USD 0.00USD 0SEC filing ↗
2026-06-12Amron Arthur HPurchase (P)Common Stock2,000USD 3.28USD 6,560SEC filing ↗
2026-06-11Amron Arthur HPurchase (P)Common Stock2,500USD 3.22USD 8,050SEC filing ↗
2026-05-28Amron Arthur HPurchase (P)Common Stock3,000USD 3.25USD 9,750SEC filing ↗
2026-05-26Amron Arthur HPurchase (P)Common Stock2,500USD 3.24USD 8,100SEC filing ↗
2025-12-11Amron Arthur HPurchase (P)Common Stock10,000USD 1.89USD 18,900SEC filing ↗

Multiple price lines in one filing are grouped and share-weighted. Price and value are blank when a grouped filing line lacks price evidence.

Snapshot & identity

Snapshot date2026-10-18
Ranking versionUS-v1.2
Data qualityPASS ELIGIBLE · —
TickerTUSK
CIK0001679268
SectorIndustrials
IndustryConglomerates Yahoo Finance
SEC SIC1389 Oil & Gas Field Services, NEC
ExchangeNasdaq

Data coverage

Local Form 4 history84 transaction lines from 2020-03-03 to 2026-09-16
21 P purchase lines · 23 S sale lines · 40 other lines
SEC company submissionsOpen SEC filings ↗

Local ledger as of 2026-10-18. Mapping status is an audit field and does not erase SEC filing evidence.