MAMMOTH ENERGY SERVICES, INC.

1. Organization and Nature of Business

Mammoth Energy Services, Inc. (“Mammoth” or the “Company”), together with its subsidiaries, is an integrated, growth-oriented company focused on providing products and services to our customers primarily in the oil and natural gas, aviation and utility infrastructure industries in North America. Mammoth’s suite of services includes rental services and aviation sales, infrastructure services, natural sand proppant services, accommodation services and drilling services. The Company’s rental services and aviation sales include a wide range of equipment used in oilfield, construction and aviation activities. The Company’s infrastructure services include providing fiber optic services to the utility infrastructure industry. The Company’s natural sand proppant services include mining, processing and selling natural sand proppant used for hydraulic fracturing. The Company’s accommodation services include housing, kitchen and dining, and recreational service facilities for workers located in remote areas away from readily available lodging. The Company’s drilling services include providing directional drilling to oilfield operators. The Company was incorporated in Delaware in June 2016.

On April 11, 2025, the Company completed a transaction to sell a portion of its infrastructure services entities, including its distribution, transmission and substation operations, for aggregate proceeds of $108.7 million. Subsequently, on June 16, 2025, the Company sold all of the equipment previously used in its hydraulic fracturing services for $15.0 million. In addition, on December 2, 2025, the Company completed a transaction to sell its engineering business for $30.0 million. These transactions reflect a strategic shift in the Company’s business. Results of operations, financial position and cash flows for these services are reported as discontinued operations for all periods presented and discussed in this report. Refer to Note 4 for further information.

2. Basis of Presentation and Significant Accounting Policies

Basis of Presentation

The accompanying unaudited condensed consolidated financial statements include the accounts of the Company and its subsidiaries and the variable interest entities (“VIE”) for which the Company is the primary beneficiary. See Note 11 for additional information regarding these entities. All intercompany accounts and transactions have been eliminated.

This report has been prepared in accordance with the rules and regulations of the Securities and Exchange Commission, and reflects all adjustments, which in the opinion of management are necessary for the fair presentation of the results for the interim periods, on a basis consistent with the annual audited consolidated financial statements. All such adjustments are of a normal, recurring nature. Certain information, accounting policies and footnote disclosures normally included in financial statements prepared in accordance with generally accepted accounting principles (“GAAP”) have been omitted pursuant to such rules and regulations, although the Company believes that the disclosures are adequate to make the information presented not misleading.

Unless otherwise indicated, information in these notes to unaudited condensed consolidated financial statements relates to continuing operations. Certain of our operations have been presented as discontinued. See Note 4 for further information.

These unaudited condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and the summary of significant accounting policies and notes thereto included in the Company’s most recent Annual Report on Form 10-K for the year ended December 31, 2025.

Reclassifications

Certain prior period balances in the unaudited condensed consolidated balance sheets and notes to the unaudited condensed consolidated financial statements have been combined or reclassified to conform to current period presentation. There was no impact on previously reported total assets, total liabilities, net income (loss) or equity for the periods presented.

Cash, Cash Equivalents and Restricted Cash

All highly liquid investments with an original maturity of three months or less are considered cash equivalents. Restricted cash at June 30, 2026 and December 31, 2025 consisted of amounts held in escrow related to the sale of certain of our infrastructure subsidiaries as discussed in Note 4.

The following table provides a reconciliation of “cash and cash equivalents” and “restricted cash” reported on the unaudited condensed consolidated balance sheets that sum to the total of the same such amounts shown on the unaudited condensed consolidated statements of cash flows (in thousands):

Marketable Securities

The Company considers all of its marketable publicly held securities as available for use in current operations, and therefore classifies these securities within current assets on the unaudited condensed consolidated balance sheets. Equity securities are measured at fair value, with changes in fair value recognized within “(Loss) gain on marketable securities, net” on the unaudited condensed consolidated statements of operations and comprehensive income (loss).

Realized gains and losses on securities sold are determined using the specific identification method and are measured based on the last reported carrying value of the securities immediately preceding the date of sale. The following table presents the components of “(Loss) gain on marketable securities, net”:

Accounts Receivable, net

Accounts receivable include amounts due from customers for services performed or goods sold. The Company grants credit to customers in the ordinary course of business and generally does not require collateral. Prior to granting credit to customers, the Company analyzes the potential customer’s risk profile by utilizing a credit report, analyzing macroeconomic factors and using its knowledge of the industry, among other factors. Customer balances are generally considered delinquent if unpaid by the due date, which generally ranges from 30 to 60 days following the invoice date, and credit privileges may be revoked if balances remain unpaid. Interest on delinquent trade accounts receivable is recognized in “other (expense) income”, net on the unaudited condensed consolidated statements of operations and comprehensive income (loss) when chargeable and collectability is reasonably assured.

The Company regularly reviews receivables and provides for expected losses through an allowance for expected credit losses. In evaluating the level of established reserves, the Company makes judgments regarding its customers’ ability to make required payments, economic events and other factors. As the financial condition of customers changes, circumstances develop, or additional information becomes available, adjustments to the allowance for expected credit losses may be required. In the event the Company expects that a customer may not be able to make required payments, the Company would increase the allowance through a charge to income in the period in which that determination is made. If it is determined that previously reserved amounts are collectible, the Company would decrease the allowance through a credit to income in the period in which that determination is made. Uncollectible accounts receivable are periodically charged against the allowance for expected credit losses once a final determination is made regarding their collectability.

Following is a rollforward of the changes in our allowance for expected credit losses for the six months ended June 30, 2026 (in thousands):

The Company has made specific reserves consistent with Company policy which resulted in additions to the allowance for expected credit losses totaling $0.1 million for the six months ended June 30, 2025. There wereno additions to the allowance for expected credit losses for the six months ended June 30, 2026. These additions were charged to credit loss expense, which is included in “selling, general and administrative” on the unaudited condensed consolidated statements of operations and comprehensive income (loss) based on the factors described above.

Substantially all of the allowance for expected credit losses relates to the receivable from the Puerto Rico Electric Power Authority (“PREPA”). Refer to the Company’s Annual Report on Form 10-K for the year ended December 31, 2025, previously filed with the SEC for more information regarding the Settlement Agreement.

PREPA

During the period October 2017 through March 2019, the Company provided infrastructure services in Puerto Rico under master services agreements entered into by Cobra Acquisitions LLC (“Cobra”), one of the Company’s subsidiaries, with the Puerto Rico Electric Power Authority (“PREPA”) to perform repairs to PREPA’s electrical grid as a result of Hurricane Maria. PREPA is currently subject to bankruptcy proceedings, which were filed in July 2017 and are currently pending in the United States District Court for the District of Puerto Rico (the “Title III Court”). On July 22, 2024, Cobra entered into a release and settlement agreement with PREPA and the Financial Oversight and Management Board for Puerto Rico (the “FOMB”), in its capacity as Title III representative for PREPA, to settle all outstanding matters between Cobra and PREPA (the “Settlement Agreement”). Pursuant to the terms of the Settlement Agreement, PREPA paid Cobra approximately $168.4 million in 2024 and, as of June 30, 2026, PREPA owes Cobra $20.0 million, which is payable within seven days following the effective date of PREPA’s plan of adjustment in its bankruptcy proceedings.

The Settlement Agreement will not be fully performed until PREPA remits the remaining $20.0 million payment.

Concentrations of Credit Risk and Significant Customers

Financial instruments that potentially subject the Company to concentrations of credit risk consist of cash and cash equivalents in excess of federally insured limits, marketable securities and trade receivables. Following is a summary of our significant customers based on percentages of total accounts receivable, net balances at June 30, 2026 and December 31, 2025 and percentages of total revenue derived for the three and six months ended June 30, 2026 and 2025:

(a)Revenue and the related accounts receivable balances earned from Customer A and E were derived from the Company’s natural sand proppant services segment.

(b)Revenue and the related accounts receivable balances earned from Customer B were derived from the Company’s drilling services segment.

(c)Revenue and the related accounts receivable balances earned from Customer C and D were derived from the Company’s rental services segment.

(d)Revenue and the related accounts receivable balances earned from Customer F were derived from the Company’s infrastructure services segment.

(e)The accounts receivable balance with Customer G was derived from the Company’s other services.

Fair Value of Financial Instruments

Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs.

The fair value hierarchy is based on three levels of input, of which the first two are considered observable and the last unobservable, that may be used to measure fair value. A financial instrument’s categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurements in its entirety requires judgment and may affect the valuation of the assets and liabilities being measured and their placement within the fair value hierarchy. The Company uses appropriate valuation techniques based on available inputs to measure the fair values of its assets and liabilities.

Level 1 - Observable inputs that reflect unadjusted quoted prices for identical assets or liabilities in active markets as of the reporting date.

Level 2 - Observable market-based inputs or unobservable inputs that are corroborated by market data. These are inputs other than quoted prices in active markets included in Level 1, which are either directly or indirectly observable as of the reporting date.

Level 3 - Unobservable inputs that are not corroborated by market data and may be used with internally developed methodologies that result in management’s best estimate of fair value.

There were no transfers into, or out of, the three levels of fair value hierarchy for the three and six months ended June 30, 2026 and 2025.

The Company’s financial instruments consist of cash and cash equivalents, marketable securities, restricted cash, accounts receivable, accounts payable as well as financing and operating lease liabilities and financed insurance premium obligations. The carrying values of cash and cash equivalents, restricted cash, accounts receivable and accounts payable approximated fair value on June 30, 2026 and December 31, 2025 due to their short-term nature. The carrying values of amounts outstanding under financing and operating lease liabilities and financed insurance premium obligations approximated fair value on June 30, 2026 and December 31, 2025, as the effective borrowing rates approximated market rates.

Recurring Measurements

The fair value of the Company’s cash equivalents and marketable securities are measured on a recurring basis are carried at estimated fair value. Cash equivalents consist of money market accounts and U.S. treasury bills which the Company has classified as Level 1 given the active market for these assets. Marketable securities are presented and are also classified as Level 1 due to their quoted prices in active markets. At June 30, 2026 and December 31, 2025, the Company had cash equivalents and marketable securities measured at fair value of $70.5 million and $113.6 million, respectively.

Nonrecurring Measurements

The Company estimates fair value to perform impairment tests on long-lived assets including property, plant and equipment and goodwill. The inputs used to determine such fair value may be based on internally developed cash flow models or market appraisals, both of which would generally be classified within Level 3 in the event that such assets were required to be measured and recorded at fair value.

As discussed in Note 7, the Company changed the classification of its drilling rig assets from held for use to held for sale at March 31, 2025, which required the Company to estimate the fair value of such assets. Cash flow models or market appraisals used to determine such fair value may be based on inputs that are classified within Level 3. The Company determined that the fair value of its drilling rig assets exceeds the carrying value and, therefore, no impairment was recognized.

Common Stock Repurchases and Retirements

The Company accounts for repurchases of its common stock at the amount paid, including direct and incremental costs such as broker commissions. Shares repurchased under the Company’s stock repurchase program are cancelled and retired, with the par value charged to common stock and the excess of the repurchase price over par value recorded as a reduction of additional paid‑in capital.

New Accounting Pronouncements

In November 2024, the FASB issued ASU 2024-03, “Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses”, which requires disclosure of specified information about certain costs and expenses. ASU 2024-03 is effective for fiscal years beginning after December 15, 2026 and interim periods beginning after December 15, 2027, with early adoption permitted, and should be applied either on a prospective basis or retrospective basis. The Company is currently assessing the impact of this ASU on the Company’s unaudited condensed consolidated financial statements.

In December 2025, the FASB issued ASU No. 2025-11, Interim Reporting (Topic 270): Narrow-Scope Improvements (“ASU 2025-11”). The amendments clarify and reorganize existing interim reporting guidance, including the scope of Topic 270 and interim disclosure requirements, and introduce a disclosure principle requiring entities to disclose material events or changes occurring since the most recent annual reporting period. ASU 2025-11 is effective for interim reporting periods within annual reporting periods beginning after December 15, 2027. Early adoption is permitted. The Company is currently evaluating the impact of ASU 2025-11 on its unaudited condensed consolidated financial statements and related disclosures.

Recently Adopted Accounting Pronouncements

In July 2025, the FASB issued ASU 2025-05, “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses for Accounts Receivable and Contract Assets,” which provides a practical expedient for estimating expected credit losses for current accounts receivable and current contract assets arising from transactions accounted for under ASC 606. The practical expedient allows entities to assume that current conditions as of the balance sheet date remain unchanged over the remaining life of the asset. The Company adopted ASU 2025-05 on January 1, 2026 and elected to apply the practical expedient. Adoption did not have a material impact on the Company’s unaudited condensed consolidated financial statements.

3. Acquisitions

Acquisition of Mission Construction and BERE Rentals

On June 12, 2026, we acquired all of the outstanding equity interests in Mission Construction LLC (“Mission Construction”), and BERE Rentals LLC (“BERE Rentals”) pursuant to equity purchase agreements with unrelated third-party sellers for aggregate consideration of $6.5 million, funded with cash on hand, including a holdback payable of $0.7 million due within one year of closing and subject to reduction for valid indemnification claims arising from customary representations, warranties and covenants. Both Mission Construction and BERE Rentals provide fiber optic services to utility customers in the midwestern region of the United States. The acquisitions were accounted for as business combinations under ASC 805, Business Combinations, with the results of Mission Construction and BERE Rentals included in the Infrastructure Services segment of our consolidated financial statements from the acquisition date. The acquisitions were undertaken to expand our presence in the fiber optic services market, broaden our services to utility customers, and strengthen our position in the region.

The following table summarizes the fair value of Mission Construction and BERE Rentals as of June 12, 2026:

The purchase price allocation presented above is preliminary and subject to change as additional information becomes available regarding the fair values of assets acquired and liabilities assumed during the measurement period. The acquired customer relationship and trade name intangible assets each have an estimated useful life ofseven years.

4. Discontinued Operations

T&D Transaction

On April 11, 2025, Lion Power Services LLC (“Lion”), a subsidiary of the Company, entered into an Equity Interest Purchase Agreement (the “T&D Agreement”), as the seller, with Peak Utility Services Group, Inc. (“Peak”), as the buyer, pursuant to which Lion sold all equity interests in its wholly-owned subsidiaries 5 Star Electric, LLC (“5 Star”), Higher Power Electrical, LLC (“Higher Power”) and Python Equipment LLC (“Python”) (the “T&D Transaction”). These subsidiaries provided transmission, distribution and substation services and were previously included in the Company’s Infrastructure segment, as defined in Note 19. The T&D Transaction was completed simultaneously with the signing of the T&D Agreement on April 11, 2025. The aggregate sales price in connection with the T&D Transaction was approximately $108.7 million. Of the $108.7 million, $98.3 million was paid to Lion and the remaining $10.4 million was deposited into an escrow account, pursuant to the terms of the T&D Agreement. Of the $10.4 million deposited into an escrow account, $0.8 million has been received, leaving $9.6 million left in the restricted cash balance. The T&D Agreement includes customary representations, warranties and covenants by the parties. In addition, the T&D Agreement provides for customary indemnification rights with respect to a breach of a representation, warranty or covenant by either party, subject to customary thresholds and caps on liability.

Pressure Pumping Transaction

On June 16, 2025, Stingray Pressure Pumping LLC (“Stingray”) and Mammoth Equipment Leasing LLC (“Mammoth

Equipment”), subsidiaries of the Company, entered into an Equipment Purchase Agreement (the “Pressure Pumping Agreement”), as the sellers, with MGB Manufacturing, LLC (“MGB”), as the buyer, pursuant to which Stingray and Mammoth Equipment sold all of the Company’s equipment used in its hydraulic fracturing services, which was included in the Company’s historical well completion segment, to MGB for $15.0 million (the “Pressure Pumping Transaction” and collectively with the T&D Transaction, the “Transactions”). The Pressure Pumping Transaction was completed simultaneously with the signing of the Pressure Pumping Agreement on June 16, 2025. In conjunction with the Pressure Pumping Transaction, the Company has ceased operations of its sand hauling and equipment manufacturing services, which operations primarily served Stingray and Mammoth Equipment. All assets and liabilities associated with the Company’s sand hauling and equipment manufacturing services are included in discontinued operations.

Engineering Transaction

On December 2, 2025, Mammoth Energy Partners LLC ("MEP"), a subsidiary of the Company, entered into an Equity Purchase Agreement (the “Agreement”), as the seller, with Qualus, LLC (“Qualus”), as the buyer, and Aquawolf LLC ("Aquawolf"), MEP's wholly-owned subsidiary and the subject of the sale, as a party to the Agreement. Pursuant to the Agreement, MEP sold all equity interests in Aquawolf, which was included in the Company’s Infrastructure segment, to Qualus for $30.0 million (the “Engineering Transaction” and collectively with the Pressure Pumping Transaction and T&D Transaction, the “Transactions”)). The Engineering Transaction was completed simultaneously with the signing of the Agreement on December 2, 2025. The aggregate sales price in connection with the Transaction was approximately $30.0 million. Of the $30.0 million, $23.5 million was paid to MEP and $2.5 million was deposited into an escrow account, pursuant to the terms of the Agreement. Of the $2.5 million deposited into an escrow account, $0.2 million has been received, leaving $2.3 million left in the restricted cash balance. The Agreement includes customary representations, warranties and covenants by the parties. In addition, the Agreement provides for customary indemnification rights with respect to a breach of a representation, warranty or covenant by either party, subject to customary thresholds and caps on liability.

The Transactions and ceasing operations of the Company’s sand hauling and equipment manufacturing services reflect a strategic shift in the Company’s business. Therefore, the results of operations and cash flows of the services discussed above are classified as discontinued operations in the Company’s unaudited condensed consolidated statements of operations and comprehensive income (loss) and unaudited condensed consolidated statements of cash flows for all periods presented. The related assets and liabilities associated with the discontinued operations are included in the financial statement line items labeled discontinued operations in the unaudited condensed consolidated balance sheets as of June 30, 2026 and December 31, 2025. Amounts presented in discontinued operations have been derived from our consolidated financial statements and accounting records using the historical basis of assets, liabilities, results of operations and cash flows of the services discussed above. The discontinued operations exclude general corporate allocations.

The following table presents the major classes of assets and liabilities of discontinued operations (in thousands):

The following tables present the major components from discontinued operations in the Company’s unaudited condensed consolidated statements of operations and comprehensive income (loss) (in thousands):

5. Revenue from Contracts with Customers

The Company’s primary revenue streams include rental services and aviation sales, infrastructure services, natural sand proppant services, accommodation services and drilling services. See Note 19 for the Company’s revenue disaggregated by type.

Certain of the Company’s customer contracts include provisions entitling the Company to a termination penalty when the customer invokes its contractual right to terminate prior to the contract’s nominal end date. The termination penalties in the customer contracts vary, but are generally considered substantive for accounting purposes and create enforceable rights and obligations throughout the stated duration of the contract. The Company accounts for a contract cancellation as a contract modification in the period in which the customer invokes the termination provision. The determination of the contract termination penalty is based on the terms stated in the related customer agreement. As of the modification date, the Company updates its estimate of the transaction price using the expected value method, subject to constraints, and recognizes the amount over the remaining performance period.

Rental, Accommodation and Drilling Services

Rental services, accommodation services and drilling services are generally provided pursuant to purchase orders, master service agreements, customer contracts or on a spot market basis. Services are typically billed on a day rate, hourly, contract or utilization basis. Performance obligations for these services are satisfied over time and revenue is recognized as services are performed using an appropriate measure of output. Contract durations are generally short-term in nature and may range from a single day to several months.

In addition, the Company generates revenue from aviation leasing and aviation sales. Revenue from aviation leases is recognized in accordance with the contractual terms. Revenue from aviation equipment sales is recognized at the point in time when control of the equipment transfers to the customer, generally upon delivery. Revenue from aviation leasing and other rental services is included in “services revenue”, while revenue from aviation sales is included in “product revenue” on the unaudited condensed consolidated statements of operations and comprehensive income (loss). The cost of aviation equipment sold is included in “product cost of revenue”. The proceeds from sale of aviation equipment are included in investing activities in the unaudited condensed consolidated statements of cash flows.

Infrastructure Services

Infrastructure services are typically provided pursuant to master service agreements, repair and maintenance contracts or fixed price and non-fixed price installation contracts. Pricing under these contracts may be unit priced, cost-plus/hourly (or time and materials basis) or fixed price (or lump sum basis). Generally, the Company accounts for infrastructure services as a single performance obligation satisfied over time. In certain circumstances, the Company supplies materials that are utilized during the jobs as part of the agreement with the customer. The Company accounts for these infrastructure agreements as multiple performance obligations satisfied over time. Revenue is recognized over time as work progresses based on progress toward completion utilizing an appropriate measure of output. Under certain customer contracts in our infrastructure services segment, the Company warranties equipment and labor performed for a specified period following substantial completion of the work.

Natural Sand Proppant Services

The Company sells natural sand proppant through sand supply agreements with its customers. Under these agreements, sand is typically sold at a flat rate per ton or a flat rate per ton with an index-based adjustment. The Company recognizes revenue at the point in time when the customer obtains legal title to the product, which may occur at the production facility, rail origin or at the destination terminal.

Certain of the Company’s sand supply agreements contained a minimum volume commitment related to sand purchases whereby the Company charges a shortfall payment if the customer fails to meet the required minimum volume commitment. These agreements may also contain make-up provisions whereby shortfall payments can be applied in future periods against purchased volumes exceeding the minimum volume commitment. If a make-up right exists, the Company has future performance obligations to deliver excess volumes of product in subsequent months. In accordance with ASC 606, if the customer fails to meet the minimum volume commitment, the Company will assess whether it expects the customer to fulfill its unmet commitment during the contractually specified make-up period based on discussions with the customer and management’s knowledge of the business. If the Company expects the customer will make-up deficient volumes in future periods, revenue related to shortfall payments will be deferred and recognized on the earlier of the date on which the customer utilizes make-up volumes or the likelihood that the customer will exercise its right to make-up deficient volumes becomes remote. If the Company does not expect the customer will make-up deficient volumes in future periods, the breakage model will be applied and revenue related to shortfall payments will be recognized when the model indicates the customer’s inability to take delivery of excess volumes. The Company didnot recognize any shortfall revenue during the three and six months ended June 30, 2026. The Company recognized shortfall revenue totaling $1.6 million during the six months ended June 30, 2025.

In certain of the Company’s sand supply agreements, the customer obtains control of the product when it is loaded into rail cars and the customer reimburses the Company for all freight charges incurred. The Company has elected to account for shipping and handling as activities to fulfill the promise to transfer the sand. If revenue is recognized for the related product before the shipping and handling activities occur, the Company recognizes the related costs of those shipping and handling activities.

Practical Expedients

The Company does not disclose the value of unsatisfied performance obligations for (i) contracts with an original expected length ofone year or less and (ii) contracts in which variable consideration is allocated entirely to a wholly unsatisfied performance obligation or to a wholly unsatisfied distinct good or service that forms part of a single performance obligation.

Contract Balances

Following is a rollforward of the Company’s contract liabilities, which are included in “accrued expenses and other current liabilities” on the unaudited condensed consolidated balance sheets (in thousands):

The Company didnot have any contract assets at June 30, 2026 and December 31, 2025.

Performance Obligations

Revenue recognized in the current period from performance obligations satisfied in previous periods wasimmaterial for the three and six months ended June 30, 2026 and 2025. At June 30, 2026, the Company had unsatisfied performance obligations totaling $2.9 million, which will be recognized over the next 7 months.

6. Inventories

Inventories consist of raw sand, processed sand and parts available for sale and supplies used in performing services, as well as aviation equipment being repaired for their intended use. Inventory is stated at the lower of cost or net realizable value on an average cost basis. The Company assesses the valuation of its inventories based upon specific usage, future utility, obsolescence and other factors. A summary of the Company’s inventories is shown below (in thousands):

7. Property, Plant and Equipment, net and Assets Held for Sale

Property, plant and equipment, net includes the following (in thousands):

(a) This equipment relates to assets leased and available to be leased to customers under operating leases.

(b) Includes accumulated depreciation of $10.6 million and $5.7 million at June 30, 2026 and December 31, 2025, respectively, related to assets under operating leases.

Depreciation, depletion, amortization and accretion

A summary of depreciation, depletion, amortization and accretion is below (in thousands):

Assets Held for Sale

The Company’s assets held for sale consist solely of its contract drilling assets, which were classified as held for sale during the first quarter of 2025 pursuant to a plan to divest these assets. The Company continues to actively market the assets at a price that is reasonable in relation to their current fair value and remains committed to its plan of sale. At June 30, 2026 and December 31, 2025, assets held for sale totaled $2.2 million and $4.3 million and were recorded in “current assets held for sale” on the unaudited condensed consolidated balance sheets. These assets are measured at the lower of their carrying amount or fair value less costs to sell, andno impairment was recognized during the three and six months ended June 30, 2026.

8. Equity Method Investment

On December 21, 2018, Cobra Aviation Services LLC (“Cobra Aviation”) and Wexford Partners Investment Co. LLC (“Wexford Investment”), a related party, formed a joint venture under the name of Brim Acquisitions LLC (“Brim Acquisitions”) to acquire all outstanding equity interest in Brim Equipment Leasing, Inc. (“Brim Equipment”) for a total purchase price of approximately $2.0 million. Cobra Aviation owns a 49% economic interest and Wexford Investment owns a 51% economic interest in Brim Acquisitions, and each member contributed its pro rata portion of Brim Acquisitions’ initial capital of $2.0 million. Brim Acquisitions, through Brim Equipment, owns three commercial helicopters and leasestwo commercial helicopters for operations, which it uses to provide a variety of services, including short haul, aerial ignition, hoist operations, aerial photography, fire suppression, construction services, animal/capture/survey, search and rescue, airborne law enforcement, power line construction, precision long line operations, pipeline construction and survey, mineral and seismic exploration, and aerial seeding and fertilization.

The Company uses the equity method of accounting to account for its investment in Brim Acquisitions, which had a carrying value of approximately $2.9 million and $3.2 million at June 30, 2026 and December 31, 2025, respectively. The investment is included in “other non-current assets” on the unaudited condensed consolidated balance sheets. The Company recorded equity method income (loss) to its investment of $0.2 million and ($0.3) million for the three and six months ended June 30, 2026, respectively, and equity method income of $0.4 million and $0.3 million for the three and six months ended June 30, 2025, respectively, which is included in “other income (expense), net” on the unaudited condensed consolidated statements of operations and comprehensive income (loss). The investment in Brim Acquisitions is included in the Company’s Rentals segment, as defined in Note 19. The Company made additional equity contributions of $0.4 million during the year ended December 31, 2025 andno contributions were made during the six months ended June 30, 2026.

9. Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities included the following (in thousands):

(a)Financed insurance premiums are due in monthly installments, are unsecured and mature within the twelve-month period following the close of the year. At June 30, 2026 the applicable interest rate associated with financed insurance premiums was 5.49%. At December 31, 2025, the applicable interest rate associated with financed insurance premiums ranged from 5.49% to 6.49%.

10. Debt

Revolving Credit Facility

On May 8, 2026, the Company entered into a new $25.0 million revolving credit agreement with Fifth Third Bank, National Association (the “new revolving credit facility”) and terminated its prior revolving credit facility, dated October 16, 2023, as amended (the “prior revolving credit facility”). The new revolving credit facility matures on May 8, 2029 and may be increased to up to $50.0 million at the Company’s request, subject to the lender’s sole discretion. Borrowings bear interest at one-month Term SOFR plus 1.50% per annum, and the Company pays a 0.20% per annum fee on the unused commitments. The facility is secured by a first-priority lien on cash and investment securities held in a collateral account maintained with the lender, the value of which, after applying specified advance rates, must equal at least 100% of outstanding borrowings and letter of credit obligations. The new revolving credit facility is not guaranteed by the Company’s subsidiaries and does not contain a financial maintenance covenant based on the Company’s operating results or any restriction on the payment of dividends or the repurchase of the Company’s common stock. In connection with the termination of the prior revolving credit facility, the Company wrote off $1.2 million of unamortized debt issuance costs during the three months ended June 30, 2026.

At June 30, 2026, the new revolving credit facility was undrawn and there was $20.0 million of borrowing capacity under the facility, after giving effect to $5.0 million of outstanding letters of credit deemed issued thereunder. At December 31, 2025, the prior revolving credit facility was undrawn and there was $36.7 million of borrowing capacity under that facility, after giving effect to $5.0 million of outstanding letters of credit. The Company was in compliance with all covenants under the new revolving credit facility at June 30, 2026.

11. Variable Interest Entities

Dire Wolf Energy Services LLC (“Dire Wolf”) and Predator Aviation LLC (“Predator Aviation”), wholly owned subsidiaries of the Company, are party to Voting Trust Agreements with TVPX Aircraft Solutions Inc. (the “Voting Trustee”). Under the Voting Trust Agreements, Dire Wolf transferred 100% of its membership interest in Cobra Aviation and Predator Aviation transferred 100% of its membership interest in Leopard Aviation LLC (“Leopard”) to the respective Voting Trustees in exchange for Voting Trust Certificates. Dire Wolf and Predator Aviation retained the obligation to absorb all expected returns or losses of Cobra Aviation and Leopard. Prior to the transfer of the membership interest to the Voting Trustee, Cobra Aviation was a wholly owned subsidiary of Dire Wolf and Leopard was a wholly owned subsidiary of Predator Aviation. Cobra Aviation owns aviation equipment, including eight aircraft that are owned through individual trusts that are each structured as separate legal entities, and 49% of the equity interest in Brim Acquisitions. Leopard owns aviation equipment. Dire Wolf and Predator Aviation entered into the Voting Trust Agreements in order to meet certain registration requirements.

Dire Wolf’s and Predator Aviation’s voting rights are not proportional to their respective obligations to absorb expected returns or losses of Cobra Aviation and Leopard, respectively, and all of Cobra Aviation’s and Leopard’s activities are conducted on behalf of Dire Wolf and Predator Aviation, which have disproportionately fewer voting rights; therefore, Cobra Aviation and Leopard meet the criteria of a VIE. Cobra Aviation and Leopard’s operational activities are directed by Dire Wolf’s and Predator Aviation’s officers and Dire Wolf and Predator Aviation have the option to terminate the Voting Trust Agreements at any time. Therefore, the Company, through Dire Wolf and Predator Aviation, is considered the primary beneficiary of the VIEs and consolidates Cobra Aviation and Leopard at June 30, 2026.

12. Income Taxes

The Company recorded income tax expense from continuing operations of $3.3 million for the six months ended June 30, 2026 compared to income tax benefit of $0.1 million for the six months ended June 30, 2025. The Company’s effective tax rates were 48.7% and 0.2% for the six months ended June 30, 2026 and 2025, respectively.

The effective tax rate for the six months ended June 30, 2026 differed from the statutory rate of 21% primarily due to changes in the valuation allowance and interest and penalties recognized during the period. The effective tax rate for the six months ended June 30, 2025 differed from the statutory rate of 21% primarily due to changes in the valuation allowance and interest and penalties recognized during the period.

On July 4, 2025, the One Big Beautiful Bill Act (the “OBBBA”) was enacted in the United States. The legislation made several changes to U.S. federal income tax law, including provisions allowing 100% bonus depreciation for certain qualifying depreciable property acquired and placed in service after January 19, 2025, and changes to the business interest expense limitation under Section 163(j) for tax years beginning after December 31, 2024. The Company considered the impact of these provisions to estimate its income tax provision for the six months ended June 30, 2026, including the expected impact on future cash taxes.

13. Leases

Lessee Accounting

The Company recognizes a lease liability equal to the present value of the lease payments and an operating lease right-of-use asset representing its right to use the underlying asset for the lease term for all leases with a term in excess of 12 months. For operating leases, lease expense for lease payments is recognized on a straight-line basis over the lease term, while finance leases include both an operating expense and an interest expense component. For all leases with a term of 12 months or less, the Company has elected the practical expedient to not recognize lease assets and liabilities and recognizes lease expense for these short-term leases on a straight-line basis over the lease term.

The Company’s operating leases are primarily for rail cars, real estate, and equipment and its finance leases are primarily for vehicles and equipment. Generally, the Company does not include renewal or termination options in its assessment of the leases unless extension or termination of certain assets is deemed to be reasonably certain. The accounting for some of the Company’s leases may require significant judgment, which includes determining whether a contract contains a lease, determining the incremental borrowing rates to utilize in the net present value calculation of lease payments for lease agreements which do not provide an implicit rate and assessing the likelihood of renewal or termination options. Lease agreements that contain a lease and non-lease component are generally accounted for as a single lease component.

The rate implicit in the Company’s leases is not readily determinable. Therefore, the Company uses its incremental borrowing rate based on information available at the commencement date of its leases in determining the present value of lease payments. The Company’s incremental borrowing rate reflects the estimated rate of interest that it would pay to borrow on a collateralized basis over a similar term an amount equal to the lease payments in a similar economic environment.

Lease expense consisted of the following for the three and six months ended June 30, 2026 and 2025 (in thousands):

Right-of-use assets and liabilities related to finance leases are recorded in the following line items on the unaudited condensed consolidated balance sheets at June 30, 2026 and December 31, 2025 (in thousands):

Other supplemental information related to leases for the three and six months ended June 30, 2026 and 2025 and at June 30, 2026 and December 31, 2025 is as follows (in thousands):

Maturities of lease liabilities at June 30, 2026 are as follows (in thousands):

Lessor Accounting

Certain rental and accommodation service arrangements contain lease components under ASC 842. The Company has elected the practical expedient to combine the lease and non-lease components when permitted. Revenue from these arrangements is generally recognized over time based on the contractual rental period. The Company recognized lease revenue of $5.0 million and $8.9 million during the three and six months ended June 30, 2026, respectively, and $1.0 million and $1.2 million during the three and six months ended June 30, 2025, respectively, which is included in “services revenue” and “services revenue - related parties” on the unaudited condensed consolidated statements of operations and comprehensive income (loss).

Maturities of lease payments for the Company’s outstanding long-term leases at June 30, 2026 are as follows (in thousands):

14. Earnings Per Share

Reconciliations of the components of basic and diluted net earnings per share are presented in the table below (in thousands, except per share data):

(a) Excludes 94 and 93 shares for the three and six months ended June 30, 2025 of potentially dilutive restricted stock awards as their effect was antidilutive under the treasury stock method.

15. Equity Based Compensation

During June 2026, all outstanding Specified Member and Non-Employee Member awards were settled through the transfer of shares of Mammoth common stock by the majority equity holder of MEH Sub. As a result, all rights under the awards were cancelled and extinguished. The Company recognized equity based compensation expense of approximately $0.5 million during the three and six months ended June 30, 2026, with a corresponding capital contribution recorded in equity. No unrecognized compensation cost remained as of June 30, 2026.

16. Stock Based Compensation

On April 29, 2024, the board of directors of Mammoth adopted the Mammoth Energy Services, Inc. 2024 Equity Incentive Plan (the “2024 Plan”). The 2024 Plan authorizes the Company’s board of directors or the compensation committee of the Company’s board of directors to grant restricted stock, restricted stock units, stock appreciation rights, stock options and performance awards. There are a maximum of 1.9 million shares of common stock reserved for issuance under the 2024 Plan, of which 1.9 million shares of common stock remain available for future grants under the 2024 Plan at June 30, 2026.

Restricted Stock Units

The fair value of restricted stock unit awards was determined based on the fair market value of the Company’s common stock on the date of the grant. This value is amortized over the vesting period. At June 30, 2026, there wasno unrecognized compensation cost. No shares vested during the three and six months ended June 30, 2026. The total fair value of shares vested was $0.5 million and $0.6 million during the three and six months ended June 30, 2025, respectively. Included in “selling, general and administrative” on the unaudited condensed consolidated statements of operations and comprehensive income (loss) is stock based compensation expense of $0.2 million and $0.4 million for the three and six months ended June 30, 2025, respectively.

17. Related Party Transactions

Transactions between the subsidiaries of the Company and the following companies are included in related party transactions: Wexford, El Toro Resources LLC, Caliber Investment Group LLC, Grizzly Oil Sands ULC, Brim Equipment and Executive Express Aviation LLC. The Company provides accommodations services to Grizzly Oil Sands ULC and engages in aircraft leasing arrangements with Brim Equipment. Revenue from related party transactions was $0.2 million and $0.7 million for the three and six months ended June 30, 2026, respectively, and $0.6 million and $0.7 million for the three and six months ended June 30, 2025, respectively. Costs incurred from related party transactions was $0.1 million and $0.2 million for the three and six months ended June 30, 2025, respectively. At June 30, 2026 and December 31, 2025, accounts receivable from related party transactions was $0.4 million and $0.4 million, which is included in “accounts receivable, net” on the unaudited condensed consolidated balance sheets. There wereno accounts payable for related party transactions at June 30, 2026 and December 31, 2025.

On December 21, 2018, Cobra Aviation purchasedtwo commercial helicopters, spare parts, support equipment and aircraft documents from Brim Equipment. Following these transactions, and also on December 21, 2018, Cobra Aviation formed a joint venture with Wexford Investment named Brim Acquisitions to acquire all outstanding equity interests in Brim Equipment. Cobra Aviation owns a 49% economic interest and Wexford Investment owns a 51% economic interest in Brim Acquisitions, and each member contributed its pro rata portion of Brim Acquisitions’ initial capital of $2.0 million. Wexford Investment is an entity controlled by Wexford. Cobra Aviation and Leopard each leaseone helicopter to Brim Equipment under the terms of aircraft lease and management agreements.

On February 23, 2026, Mammoth Energy Partners LLC, a subsidiary of the Company, entered into a sublease agreement with El Toro Resources LLC, an entity controlled by Wexford and a related party of the Company. The agreement was subject to approval by Mammoth Energy Partners LLC's landlord, which approval was obtained on March 16, 2026. The sublease relates to office space located at 14201 Caliber Drive, Suite 200, Oklahoma City, Oklahoma. The sublease began on June 1, 2026 and extends through May 31, 2027, with an option to extend through April 30, 2028. The aggregate minimum lease payments under the agreement are approximately $0.2 million.

On June 2, 2026, and July 28, 2026, Cobra Aviation, a subsidiary of the Company, entered into separate aircraft lease agreements with Executive Express Aviation LLC, an entity controlled by Wexford and a related party of the Company. The first lease relates to a Pilatus Model PC12/45 aircraft, while the second lease relates to a Raytheon Aircraft Company Model 1900D aircraft. Both leases are expected to commence on August 31, 2026 and extend through August 31, 2029. The aggregate minimum lease payments under the Pilatus and Raytheon leases are approximately $1.1 million and $1.3 million, respectively.

18. Commitments and Contingencies

Commitments

From time to time, the Company may enter into agreements with suppliers that contain minimum purchase obligations and agreements to purchase capital equipment. Aggregate future minimum payments under these obligations in effect at June 30, 2026 were approximately $6.2 million.

Letters of Credit

The Company had outstanding letters of credit related to environmental remediation and insurance programs that were issued under the Company’s revolving credit facility, which is collateralized by cash and investment securities held in a collateral account maintained with the lender, totaling $5.0 million at June 30, 2026 and December 31, 2025.

Insurance

The Company has insurance coverage for physical partial loss to its assets, employer’s liability, automobile liability, commercial general liability, workers’ compensation and insurance for other specific risks. At June 30, 2026 and December 31, 2025, there was no deductible for the workers’ compensation policy. At June 30, 2026 and December 31, 2025, the Company’s primary automobile liability policy required a deductible per occurrence of up to $0.1 million.

Effective November 1, 2024, the Company became party to a deductible reimbursement insurance policy from a protected cell captive insurance company that covers losses between $0.1 million and the $0.5 million deductible under its primary auto liability policy that was in effect through October 31, 2025. Also effective November 1, 2024, the Company became a member of a group captive insurance company that covers one layer of its auto liability coverage.

The Company establishes liabilities for the unpaid deductible portion of claims incurred based on estimates. At June 30, 2026 and December 31, 2025, total accrued claims for continuing and discontinued operations were $0.6 million and

$1.2 million, respectively. Of this amount, $0.3 million and $0.4 million at June 30, 2026 and December 31, 2025, respectively, relate to continuing operations.

The Company also has insurance coverage for directors and officers liability. As of June 30, 2026 and December 31, 2025, the directors and officers liability policy had a deductible per occurrence of $1.5 million and an aggregate deductible of $10.0 million. As of June 30, 2026 and December 31, 2025, the Company did not have any accrued claims for directors and officers liability.

Effective January 1, 2026, the Company transitioned to a fully insured employee health insurance plan. Through December 31, 2025, the Company self-insured its employee health insurance. At June 30, 2026 and December 31, 2025, total accrued claims for continuing and discontinued operations were $0.3 million and $0.9 million, respectively. Of these amounts, $0.3 million at June 30, 2026 and December 31, 2025, respectively, relate to continuing operations. These estimates may change in the near term as actual claims continue to develop.

Bonds

In the ordinary course of business, the Company is required to provide bid bonds to certain customers in the infrastructure services segment as part of the bidding process. These bonds provide a guarantee to the customer that the Company, if awarded the project, will perform under the terms of the contract. Bid bonds are typically provided for a percentage of the total contract value. Additionally, the Company may be required to provide performance and payment bonds for contractual commitments related to projects in process. These bonds provide a guarantee to the customer that the Company will perform under the terms of a contract and that the Company will pay subcontractors and vendors. If the Company fails to perform under a contract or to pay subcontractors and vendors, the customer may demand that the surety make payments or provide services under the bond. The Company must reimburse the surety for expenses or outlays it incurs. At June 30, 2026 and December 31, 2025, there wereno outstanding performance and payment bonds andno outstanding bid bonds that related to the Company's continuing operations.

Litigation

PREPA

Foreman Electric Services, Inc. (“Foreman”) and related parties asserted claims against Mammoth and Cobra arising from Puerto Rico restoration work performed by Cobra. As discussed in Note 2, PREPA owes Cobra $20.0 million as of June 30, 2026 pursuant to the Settlement Agreement entered into in July 2024. Payment is due following the effective date of PREPA's plan of adjustment.

Other Litigation

In July 2025, the Company settled the matter with Foreman. The settlement did not have a material adverse effect on the Company’s business, financial condition, results of operations or cash flows.

The Company is routinely involved in state and local tax audits. During 2015, the State of Ohio assessed taxes on the purchase of equipment the Company believes is exempt under state law. The Company appealed the assessment and a hearing was held in 2017. As a result of the hearing, the Company received a decision from the State of Ohio, which the Company appealed. On February 25, 2022, the Company received an unfavorable decision on the appeal. The Company appealed the decision. On August 2, 2023, the Ohio Supreme Court affirmed the ruling in part and reversed the ruling in part. The Company received the final assessment in April 2025. It did not have a material adverse effect on the Company’s business, financial condition, results of operations or cash flows.

Cobra has been named in 15 lawsuits brought by municipalities in Puerto Rico seeking construction excise taxes and volume of business taxes associated with restoration work performed in Puerto Rico. Several adverse judgments have been entered, and certain matters remain subject to ongoing appellate and post-judgment proceedings. Cobra continues to challenge these assessments and intends to vigorously defend these matters. In connection with the Settlement Agreement entered into with PREPA, PREPA and related governmental parties have agreed to cooperate with Cobra in connection with the resolution of these matters. However, there can be no assurance that these efforts will be successful. Based on the current status of the proceedings, management is unable to reasonably estimate a range of possible loss, if any, beyond amounts already accrued. Accordingly no additional liability has been recorded. The Company will continue to evaluate these matters as additional information becomes available.

On April 16, 2019, Christopher Williams, a former employee of Higher Power Electrical, LLC, filed a putative class and collective action complaint titled Christopher Williams, individually and on behalf of all others similarly situated v.

Higher Power Electrical, LLC, Cobra Acquisitions LLC, and Cobra Energy LLC in the U.S. District Court for the District of Puerto Rico. On June 24, 2019, the complaint was amended to replace Mr. Williams with Matthew Zeisset as the named plaintiff. The plaintiff alleges the defendant failed to pay overtime wages to a class of workers in compliance with the Fair Labor Standards Act and Puerto Rico law. On August 21, 2019, upon request of the parties, the Court stayed proceedings in the lawsuit and administratively closed the case pending completion of individual arbitration proceedings initiated by Mr. Zeisset and opt-in plaintiffs. Other claimants subsequently initiated additional individual arbitration proceedings asserting similar claims. The Company has agreed to settlements with a portion of the claimants. Arbitrations remain pending for the remaining claimants. The Company will continue to vigorously defend the arbitrations. The Company has recognized an estimated liability related to the remaining complaints, which is included in “accounts payable” in the accompanying unaudited condensed consolidated balance sheets. The amount required to resolve these matters may ultimately increase or decrease from the Company’s estimated amount as the matters progress.

The Company is involved in various other legal proceedings in the ordinary course of business. Although the Company cannot predict the outcome of these proceedings, legal matters are subject to inherent uncertainties and there exists the possibility that the ultimate resolution of these matters could have a material impact on the Company’s business, financial condition, results of operations or cash flows.

Defined Contribution Plan

The Company sponsors a 401(k) defined contribution plan for the benefit of substantially all employees at their date of hire. The plan allows eligible employees to contribute up to 92% of their annual compensation, not to exceed annual limits established by the federal government. The Company makes discretionary matching contributions of up to 3% of an employee’s compensation and may make additional discretionary contributions for eligible employees. For the three and six months ended June 30, 2026 and 2025, the Company paid $0.1 million, $0.2 million, $0.3 million and $0.8 million, respectively, in contributions to the plan. Of these amounts for the three and six months ended June 30, 2026 and 2025, $0.1 million, $0.2 million, $0.1 million and $0.1 million, respectively, relates to continuing operations.

19. Reportable Segments

The Company’s Chief Operating Officer, Chief Financial Officer and Chief Business Officer comprise the Company’s chief operating decision makers (“CODM”). Segment information is prepared on the same basis that the CODM manages the segments, evaluates the segment financial statements and makes key operating and resource utilization decisions. Segment evaluation is determined on a quantitative basis based on a function of Adjusted EBITDA, as well as a qualitative basis, such as nature of the product and service offerings and types of customers. The Company defines Adjusted EBITDA as net income (loss) from continuing operations before depreciation, depletion, amortization and accretion, gains on disposal of assets, net, impairment of long lived assets, equity based compensation, stock based compensation, interest income, net, inclusive of related parties, (loss) gain on marketable securities, net, other (income) expense, net and provision for income taxes. The Company’s significant segment expenses include cost of revenue, exclusive of depreciation, depletion, amortization and accretion, and selling, general and administrative expense.

The Company principally provides products and services to customers operating in the oil and natural gas, aviation and utility infrastructure industries. At June 30, 2026, the Company hadfive reportable segments, which includes rental services (“Rentals”), infrastructure services (“Infrastructure”), natural sand proppant services (“Sand”), accommodation services (“Accommodations”) and drilling services (“Drilling”). The Company has determined that its operating segments meet the criteria in ASC Topic 280, Segment Reporting, and are reported asfive reportable segments.

Sales from one segment to another are generally priced at estimated equivalent commercial selling prices. All transactions conducted between segments are eliminated in consolidation. Transactions conducted by companies within the same reportable segment are eliminated within each reportable segment. Corporate selling, general and administrative costs are allocated to each segment based on forecasted revenue, expense and asset base. Corporate interest expense is allocated to each segment based on its intercompany payable position with the Company’s corporate entity. U.S. income tax expense is not allocated to each segment. Foreign income tax expense is realized in the segment in which the foreign operations occur.

To reflect how the CODM evaluates the business, prior period segment information has been recast to conform with our reportable segment composition as of June 30, 2026. The following tables set forth certain financial information with respect to the Company’s reportable segments (in thousands):

20. Subsequent Events

On July 27, 2026, the Company committed to purchase three aircraft for an aggregate purchase price of $32.4 million. As part of this commitment, the Company made a non-refundable security deposit of approximately $0.6 million. As of the date of issuance of these financial statements, definitive purchase agreements had not been executed.

On July 30, 2026, Cobra Aviation entered intotwo separate purchase agreements with a third‑party seller to purchasetwo auxiliary power units (“APUs”) for aggregate consideration of approximately $7.1 million. In connection with these agreements, the Company made a non-refundable deposit of approximately $0.4 million. On July 31, 2026, the Company completed the purchase ofone of the APUs for approximately $3.6 million.

On July 31, 2026, Stingray Rentals committed to purchase rental equipment of approximately $7.2 million.

On August 7, 2026, Cobra Aviation committed to sell an aircraft engine for $7.7 million.