Greenidge Generation Holdings Inc.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark One)

For the fiscal year ended December 31, 2025

OR

Commission File Number 001-40808

Greenidge Generation Holdings Inc.

(Exact name of Registrant as specified in its Charter)

Registrant’s telephone number, including area code: (315)536-2359

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the Registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes o No x

Indicate by check mark if the Registrant is not required to file reports pursuant to Section 13 or 15(d) of the Act. Yeso No x

Indicate by check mark whether the Registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the Registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes x Noo

Indicate by check mark whether the Registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the Registrant was required to submit such files). Yes x Noo

Indicate by check mark whether the Registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the Registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. o

Indicate by check mark whether the Registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. o

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the Registrant included in the filing reflect the correction of an error to previously issued financial statements.☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the Registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b). ☐

Indicate by check mark whether the Registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yeso Nox

Based on the closing sale price of $1.29 of the Registrant’s Class A common stock on The Nasdaq Global Select Market on June 30, 2025, the last business day of the Registrant’s most recently completed second fiscal quarter, the aggregate market value of the voting common equity held by non-affiliates of the Registrant was $14,480,618.

As of March 26, 2026, the Registrant had 13,495,756 shares of Class A common stock, $0.0001 par value per share, outstanding and 2,733,394 shares of Class B common stock, $0.0001 par value per share, outstanding.

DOCUMENTS INCORPORATED BY REFERENCE

Portions of the Registrant’s definitive proxy statement for its 2026 Annual Meeting of Stockholders are incorporated by reference in Part III of this Annual Report on Form 10-K where indicated. The Registrant’s definitive proxy statement will be filed with the Securities and Exchange Commission within 120 days after December 31, 2025.

Table of Contents

Unless otherwise indicated or the context otherwise requires, all references in this annual report on Form 10-K (this “Annual Report”) to the “Company,” “Greenidge,” “we,” “us,” “our” and similar terms refer to Greenidge Generation Holdings Inc., together with its consolidated subsidiaries.

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

This report includes certain statements that may constitute “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”), and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). All statements other than statements of historical fact are forward-looking statements for purposes of federal and state securities laws. These forward-looking statements involve uncertainties that could significantly affect our financial or operating results. These forward-looking statements may be identified by terms such as “anticipate,” “believe,” “continue,” “foresee,” “expect,” “intend,” “plan,” “may,” “will,” “would,” “could” and “should” and the negative of these terms or other similar expressions. Forward-looking statements are based on current beliefs and assumptions that are subject to risks and uncertainties and are not guarantees of future performance. Forward-looking statements in this document include, among other things, statements regarding our business plan, business strategy and operations in the future. In addition, all statements that address operating performance and future performance, events or developments that are expected or anticipated to occur in the future, including statements relating to creating value for stockholders are forward-looking statements.

Forward-looking statements are subject to a number of risks, uncertainties and assumptions. Matters and factors that could cause actual results to differ materially from those expressed or implied in such forward-looking statements include but are not limited to the matters and factors described in Item 1A, “Risk Factors” of this Annual Report, as well as statements about or relating to or otherwise affected by:

•our ability to meet our existing short-term and long-term debt obligations with the Company’s current projected operating cash flows in the long term;

•our ability to successfully maintain our power and hosting arrangements on acceptable terms, or our operations may be disrupted, and our business results may suffer, which could have a material adverse effect on our business, financial condition, and results of operations;

•fluctuations and volatility in the price of bitcoin and other cryptocurrencies;

•any failure by us to obtain acceptable financing with regard to our growth strategies or operations;

•the ability to negotiate or execute definitive documentation with respect to potential expansion sites on terms and conditions that are acceptable to Greenidge, whether on a timely basis or at all;

•changes in applicable laws, regulations, or permits, including the pathway for the issuance of our Title V Air Permit, affecting our operations or the industries in which we operate, including regulation regarding power generation, environmental laws, cryptocurrency usage and/or cryptocurrency mining, and a regulatory trend toward stricter oversight of crypto asset platforms and the cryptocurrency industry;

•loss of public confidence in, or use cases of, bitcoin and other cryptocurrencies;

•the potential of cryptocurrency market manipulation;

•the economics of hosting cryptocurrency miners, including as to variables or factors affecting the cost, efficiency and profitability of our hosting arrangements;

•the availability, delivery schedule, and cost of equipment necessary to maintain and grow our business and operations, including datacenter equipment and equipment meeting the technical or other specifications required to achieve our growth strategy;

•the possibility that we may be adversely affected by other economic, business, or competitive factors, including factors affecting the industries in which we operate or upon which we rely and are dependent;

•geopolitical instability, including conflicts in the Middle East and other regions, and related impacts on global energy markets, supply chains, critical infrastructure (including power and data systems), and cybersecurity risks;

•the ability to expand successfully to other facilities, effectively integrate and manage acquired businesses or assets, mine other cryptocurrencies, or otherwise expand our business;

•changes in tax regulations applicable to us, our assets or cryptocurrencies, including bitcoin;

•if we fail to comply with the continued listing standards of The Nasdaq Stock Market LLC (“Nasdaq”), or fail to regain compliance if required in the future, Nasdaq may delist our Class A common stock;

•any litigation involving us;

•costs and expenses relating to cryptocurrency transaction fees and fluctuation in cryptocurrency transaction fees; and

•the condition of our physical assets, including that our operating facility may realize material, if not total, loss and interference as a result of equipment malfunction or break-down, physical disaster, data security breach, computer malfunction or sabotage.

Consequently, all of the forward-looking statements made in this Annual Report are qualified by the information contained herein, including the information contained under this caption and the information in Item 1A, "Risk Factors" of this Annual Report. No assurance can be given that these are all of the factors that could cause actual results to vary materially from the forward-looking statements.

Additionally, we may provide information in this Annual Report that is not necessarily “material” under the federal securities laws for SEC reporting purposes, but that is informed by various environmental, social, and governance (“ESG”) standards and frameworks (including standards for the measurement of underlying data), and the interests of various stakeholders. Much of this information is subject to assumptions, estimates or third-party information that is still evolving and subject to change. For example, our disclosures based on any standards may change due to revisions in framework requirements, availability of information, changes in our business or applicable government policies, or other factors, some of which may be beyond our control.

You should not put undue reliance on forward-looking statements. We can provide no assurance that any of the events anticipated by the forward-looking statements will transpire or occur, or if any of them do occur, what impact they will have on the results of our operations, financial condition or cash flows. Actual results may differ materially from those discussed in this Annual Report. All forward-looking statements speak only as of the date of this Annual Report and, except as required by law, we do not assume any duty to update or revise forward-looking statements, whether as a result of new information, future events, uncertainties or otherwise, as of any future date.

Our business is subject to numerous risks and uncertainties, which illuminate challenges that we face in connection with the successful implementation of our strategy and the growth of our business. The following considerations, among others, may offset our competitive strengths or have a negative effect on our business strategy, which could adversely impact our results of operations, financial condition, or cash flows, our ability to meet our short-term and long-term debt obligations, or cause a decline in the price of our Class A common stock:

•We have experienced financial difficulties and an investment in our common stock is highly speculative. Holders of our common stock could suffer a total loss of their investment. See Note 2,“Significant Accounting Policies—Going Concern,” in the Notes to Consolidated Financial Statements.

•We may need to raise additional capital to grow our business and may not be able to do so on favorable terms, if at all. Future issuances of equity or debt securities may adversely affect the value of our common stock.

•We may not have sufficient resources to repay our 8.50% Senior Notes due 2026 (the “Senior Notes”) upon their maturity in October 2026, and we will face additional risks if we incur additional indebtedness. If we are unable to refinance, repay, exchange, or otherwise address the maturity of these notes when due, we could be in default under the terms of the notes and related agreements. Such a default could result in the acceleration of our indebtedness and could materially and adversely affect our liquidity and financial condition and, if not remedied, could require us to pursue restructuring alternatives, including a bankruptcy filing, liquidation of assets, or other similar proceedings, potentially resulting in a total loss of any investment in our Company.

•We have a history of operating losses. If we are unable to sustain greater revenues than our operating costs and support our expansion plans, we may continue to experience operating losses, which could negatively impact our results of operations, strategy and financial performance and could impair our ability to service our indebtedness.

•If we fail to comply with the Nasdaq continued listing standards, or fail to regain compliance if required in the future, Nasdaq may delist our Class A common stock.

•We have material environmental liabilities, and the costs of compliance with existing and new environmental laws and climate-related regulations could have a material adverse effect on us.

•We are exposed to customer concentration risk, substantially dependent on our sole hosting services customer, and exposed to counterparty nonperformance risk for our hosting services arrangement.

•It may take significant time, expenditure, or effort for us to grow our business, including our bitcoin datacenter operations and potential AI or HPC datacenter opportunities, whether through acquisitions, which we must effectively integrate and manage and which may present unanticipated liabilities or challenges, or through internal development efforts, which may require, among other things, technical expertise, access to capital or regulatory permits that we may not be able to obtain, and our efforts may not be successful.

•Our efforts to expand into AI and HPC datacenter opportunities may be capital intensive, which may affect our liquidity, results of operations and financial condition, and may not perform as planned. In addition, such efforts may divert resources from our core bitcoin mining operations, limit our power capacity for mining, and introduce operational complexity.

•We have experienced recent turnover in our senior management team and reduced our headcount in 2024 and 2025. If we fail to retain key talent or are unable to attract and retain other qualified personnel, our results of operations, strategy, and financial performance could be adversely affected.

•We have been, are currently, and may be in the future, the subject of legal proceedings, administrative proceedings and inquiries, audits, or probes conducted by various government agencies or regulatory bodies.

•Our revenues are largely dependent on the single natural gas power generation facility that we operate. Any disruption to our single power plant, including equipment failures, outages or damage to generation infrastructure, disruptions in fuel supply, transmission constraints or increases in energy costs, or a substantial portion of our other limited sources of revenues, would have a material adverse effect on our business and operations, as well as our results of operations and financial condition.

•Extreme weather events or other climate-related impacts could damage our infrastructure, disrupt power generation or datacenter operations, and increase our operating costs.

•We may not be able to compete effectively against other companies, some of whom have greater resources and experience or operate more efficient mining or computing infrastructure.

•As the aggregate amount of computing power, or hashrate, in the bitcoin network increases, the amount of bitcoin earned per unit of hashrate decreases; as a result, in order to maintain our market share, we may have to incur significant capital expenditures to expand our fleet of miners or replace existing mining equipment with newer, more efficient hardware.

•Our future success will depend significantly on the price of bitcoin, which is subject to risk and has historically been subject to wide swings and significant volatility.

•The bitcoin reward for successfully uncovering a block will halve several times in the future and bitcoin value may not adjust to compensate us for the reduction in the rewards we receive from our bitcoin mining efforts.

•The digital asset exchanges on which cryptocurrencies, including bitcoin, trade are relatively new and, in many cases, subject to evolving and inconsistent regulatory oversight. As a result, such platforms may be exposed to fraud, operational failures, liquidity constraints, cybersecurity incidents, or other disruptions. Periodic market events, including platform disruptions and failures that contributed to the “flash crash” in October 2025 and similar events in prior years, have contributed to significant volatility and reduced confidence in the digital asset industry. Any similar events in the future could result in declines in the price of bitcoin and other cryptocurrencies and could adversely affect the value of our digital asset holdings, our operations and financial condition, and an investment in our securities.

•The properties utilized by us in our cryptocurrency datacenter and hosting may experience damage, including damage not covered by insurance.

•While no formal regulations have been proposed to classify bitcoin as a security, if regulatory changes or interpretations classify bitcoin or other cryptocurrencies as investment securities, and we hold a significant portion of our assets in bitcoin or acquire and hold such other cryptocurrencies, we may inadvertently violate the Investment Company Act or other securities laws. We could incur large losses to modify our operations to avoid the need to register as an investment company or could incur significant expenses to register as an investment company or could terminate operations altogether.

•Regulatory changes or actions may alter the nature of an investment in us or restrict the use of bitcoin in a manner that adversely affects our business prospects, results of operations, and financial condition.

•We are subject to risks related to Internet disruptions, which could have an adverse effect on our ability to host bitcoin miners and to mine bitcoin or operate other energy-intensive computing infrastructure.

•Maintenance, expansion, and refurbishment of power generation facilities involve significant risks that could result in unplanned power outages or reduced output and could have a material adverse effect on our revenues, results of operations, cash flows, and financial condition. Our power generation facility in the Town of Torrey, New York includes certain legacy equipment, such as a steam turbine originally installed in 1953. The age and condition of certain components may increase the likelihood of additional mechanical failure, maintenance requirements, or operational disruptions, which could contribute to unplanned outages or reduced generation capacity.

•Banks and financial institutions may not provide bank accounts, or may cut off certain banking or other financial services, to cryptocurrency investors or businesses that engage in bitcoin-related activities or that accept bitcoin as payment.

•The impact of geopolitical and economic events on the supply and demand for bitcoin is uncertain.

•Bitcoin miners and other necessary hardware are subject to malfunction, technological obsolescence, the global supply chain, and difficulty and cost in obtaining new hardware.

•Our operations depend on complex information technology systems and infrastructure, and cybersecurity incidents, phishing attempts, data breaches or other technology disruptions could materially and adversely affect our operations, financial results or reputation.

•We are exposed to the impact of market price changes in bitcoin on our bitcoin holdings.

•We may not adequately respond to rapidly changing technology.

•A failure to properly monitor and upgrade the bitcoin network protocol could damage the bitcoin network which could, in turn, have an adverse effect on our business.

•Over time, incentives for bitcoin miners to continue to contribute processing power to the bitcoin network may transition from a set reward to transaction fees. If the incentives for bitcoin mining are not sufficiently high, we may not have an adequate incentive to continue datacenter operations.

•Our operations and financial performance may be impacted by fuel supply disruptions, price fluctuations in the wholesale power and natural gas markets, and fluctuations in other market factors that are beyond our control.

•Geopolitical instability, including ongoing and potential escalation of conflicts in the Middle East and other regions, may contribute to volatility in global energy markets, disrupt fuel supply, shipping routes, or critical infrastructure (including power grids and data systems), increase cybersecurity risks, and adversely affect our operating costs, supply chain, and results of operations.

The risks described above should be read together with the text of the full risk factors described in Item 1A, “Risk Factors” and the other information set forth in this report, including our consolidated financial statements and the related notes, as well as in other documents that we file with Securities and Exchange Commission (the “SEC”). Our business, prospects, results of operations or financial condition could be harmed by any of these risks, as well as other risks not currently known to us or that we currently consider immaterial. Certain statements in “Risk Factors” are forward-looking statements. See “Cautionary Statement Regarding Forward-Looking Statements” above.