Mammoth Energy Services, Inc.
DE ˙ DB ˙ US56155L1089
2,78 € ↑0,10 (3,73%)
2026-06-01
DELAT PRIS
SecurityDE:5M8 / Mammoth Energy Services, Inc.
InstitutionCitigroup Inc
Latest Disclosed Ownership1,127 shares
Latest Disclosed Value $ 2,761
Citigroup Inc reports 105.28% increase in ownership of 5M8 / Mammoth Energy Services, Inc.

On May 11, 2026 - Citigroup Inc filed a 13F-HR form disclosing ownership of 1,127 shares of Mammoth Energy Services, Inc. (DE:5M8) valued at $2,479 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 549 shares of Mammoth Energy Services, Inc.. This represents a change in shares of 105.28% during the quarter. The current value of the position is $3,133 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-05-11 2026-03-31 13F MAMMOTH ENERGY SVCS COM 56155L108 1,127 578 105.28 3 100.00 0.0000
2026-02-13 2025-12-31 13F MAMMOTH ENERGY SVCS COM 56155L108 549 -178 -24.48 1 0.00 0.0000
2025-11-10 2025-09-30 13F MAMMOTH ENERGY SVCS COM 56155L108 727 -8,731 -92.31 2 -96.15 0.0000
2025-08-11 2025-06-30 13F MAMMOTH ENERGY SVCS COM 56155L108 9,458 -7,861 -45.39 26 -25.71 0.0000
2025-05-12 2025-03-31 13F MAMMOTH ENERGY SVCS COM 56155L108 17,319 -20,852 -54.63 35 -69.30 0.0000
2025-02-12 2024-12-31 13F MAMMOTH ENERGY SVCS COM 56155L108 38,171 17,946 88.73 115 39.02 0.0001
2024-11-12 2024-09-30 13F MAMMOTH ENERGY SVCS COM 56155L108 20,225 14,568 257.52 83 355.56 0.0000
2024-08-12 2024-06-30 13F MAMMOTH ENERGY SVCS COM 56155L108 5,657 1,076 23.49 19 12.50 0.0000
2024-05-10 2024-03-31 13F MAMMOTH ENERGY SVCS COM 56155L108 4,581 1,083 30.96 17 6.67 0.0000
2024-02-09 2023-12-31 13F MAMMOTH ENERGY SVCS COM 56155L108 3,498 3,443 6,260.00 16 0.0000
2023-12-06 2023-09-30 13F/A-1 MAMMOTH ENERGY SVCS COM 56155L108 55 -6,882 -99.21 0 -100.00 0.0000
2023-11-09 2023-09-30 13F MAMMOTH ENERGY SVCS COM 56155L108 55 -6,882 0 0.0000
2023-08-10 2023-06-30 13F MAMMOTH ENERGY SVCS COM 56155L108 6,937 4,443 178.15 34 230.00 0.0000
2023-05-11 2023-03-31 13F MAMMOTH ENERGY SVCS COM 56155L108 2,494 17 0.69 11 -52.38 0.0000
2023-02-09 2022-12-31 13F MAMMOTH ENERGY SVCS COM 56155L108 2,477 2,477 21 0.0000
2022-08-10 2022-06-30 13F MAMMOTH ENERGY SVCS COM 56155L108 0 -170,000 -100.00 0 -100.00
2022-05-12 2022-03-31 13F MAMMOTH ENERGY SVCS COM 56155L108 170,000 170,000 362 0.0002
2021-08-10 2021-06-30 13F MAMMOTH ENERGY SVCS COM 56155L108 0 -6,197 -100.00 0 -100.00
2021-05-13 2021-03-31 13F MAMMOTH ENERGY SVCS COM 56155L108 6,197 303 5.14 33 26.92 0.0000
2021-02-11 2020-12-31 13F MAMMOTH ENERGY SVCS COM 56155L108 5,894 5,894 26 0.0000
2020-08-12 2020-06-30 13F MAMMOTH ENERGY SVCS COM 56155L108 0 -3,263 -100.00 0 -100.00
2020-05-12 2020-03-31 13F MAMMOTH ENERGY SVCS COM 56155L108 3,263 656 25.16 2 -66.67 0.0000
2020-02-12 2019-12-31 13F MAMMOTH ENERGY SVCS COM 56155L108 2,607 -8,755 -77.06 6 -78.57 0.0000
2019-11-08 2019-09-30 13F MAMMOTH ENERGY SVCS COM 56155L108 11,362 -2,993 -20.85 28 -71.43 0.0000
2019-08-12 2019-06-30 13F MAMMOTH ENERGY SVCS COM 56155L108 14,355 -22,557 -61.11 98 -84.07 0.0001
2019-05-13 2019-03-31 13F MAMMOTH ENERGY SVCS COM 56155L108 36,912 -97,075 -72.45 615 -74.47 0.0006
2019-02-12 2018-12-31 13F MAMMOTH ENERGY SVCS COM 56155L108 133,987 40,743 43.70 2,409 -11.24 0.0024
2018-11-13 2018-09-30 13F MAMMOTH ENERGY SVCS COM 56155L108 93,244 86,043 1,194.88 2,714 1,012.30 0.0024
2018-08-10 2018-06-30 13F MAMMOTH ENERGY SVCS COM 56155L108 7,201 6,154 587.77 244 617.65 0.0002
2018-05-11 2018-03-31 13F MAMMOTH ENERGY SVCS COM 56155L108 1,047 918 711.63 34 1,033.33 0.0000
2018-02-12 2017-12-31 13F MAMMOTH ENERGY SVCS COM 56155L108 129 127 6,350.00 3 0.0000
2017-11-13 2017-09-30 13F MAMMOTH ENERGY SVCS COM 56155L108 2 -84 -97.67 0 -100.00
2017-08-11 2017-06-30 13F MAMMOTH ENERGY SVCS COM 56155L108 86 -129 -60.00 2 -50.00 0.0000
2017-05-12 2017-03-31 13F MAMMOTH ENERGY SVCS COM 56155L108 215 -7,683 -97.28 4 -96.67 0.0000
2017-02-10 2016-12-31 13F MAMMOTH ENERGY SVCS COM 56155L108 7,898 7,898 120 0.0001
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.