Filed Pursuant to Rule 424(b)(3)
Registration No. 333-259247

PROSPECTUS

GREENIDGE GENERATION HOLDINGS INC.

10,458,474 Shares of

Class A Common Stock

This prospectus relates to the resale of 10,458,474 shares of class A common stock, $0.0001 par value, of Greenidge Generation Holdings Inc. (“Greenidge”) that may be sold from time to time by the selling stockholders named in this prospectus, which includes:

On September 14, 2021, we consummated the transactions contemplated by that certain Agreement and Plan of Merger, dated as of March 19, 2021, (the “Merger Agreement”), by and among Greenidge, Support.com, Inc. (“Support.com”) and GGH Merger Sub, Inc. (“Merger Sub”). As contemplated by the Merger Agreement, Merger Sub merged with and into Support.com, the separate corporate existence of Merger Sub ceased and Support.com survived as a wholly owned subsidiary of Greenidge (such transaction, the “Merger”).

We are registering the resale of (i) shares of class A common stock as required by the registration rights agreement, dated as of January 29, 2021, entered into by and among Greenidge and the investors in our formerly outstanding series A preferred stock and (ii) additional shares of class A common stock held by certain other stockholders.

Our registration of the securities covered by this prospectus does not mean that the selling stockholders will offer or sell any of the shares of outstanding class A common stock. The selling stockholders may offer, sell or distribute all or a portion of their shares of outstanding class A common stock publicly or through private transactions at prevailing market prices or at negotiated prices. We provide more information about how the selling stockholders may sell the shares in the section entitled “Plan of Distribution.” We will not receive any proceeds from the sales of outstanding class A common stock by the selling stockholders.

Trading of our class A common stock began on the Nasdaq Global Select Market on September 15, 2021 under the trading symbol “GREE.” On September 30, 2022, the closing sale price of our class A common stock as reported by the Nasdaq Global Select Market was $2.00.

Our class B common stock is not publicly traded. Holders of class A common stock and holders of class B common stock have substantially identical rights, except that holders of class A common stock are entitled to one vote per share and holders of shares of class B common stock are entitled to ten votes per share. Holders of class A common stock and holders of class B common stock vote together as a single class on all matters submitted to a vote of stockholders, unless otherwise required by law or our charter. Each share of class B common stock may be converted into a share of class A common stock at any time at the election of the holder.

We are an “emerging growth company” as defined in Section 2(a) of the Securities Act of 1933, as amended (the “Securities Act”), and are subject to reduced public company reporting requirements.

We are also a “controlled company” under the rules of The Nasdaq Stock Market LLC (“Nasdaq”) and may take advantage of certain corporate governance exemptions afforded to a “controlled company” under the rules of Nasdaq.

Investing in our class A common stock involves a high degree of risk. See “Risk Factors” beginning on page 5 of this prospectus and in the documents incorporated by reference in this prospectus to read about factors you should consider before you make an investment decision.

Neither the U.S. Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is October 6, 2022.

TABLE OF CONTENTS

i

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement on Form S-3 that we filed with the SEC using a “shelf” registration process. Under this shelf registration process, the selling stockholders may offer and sell from time to time the securities described in this prospectus. We will not receive any proceeds from the sale by such selling stockholders of the securities offered by them described in this prospectus.

You should rely only on the information contained in or incorporated by reference into this prospectus. Neither we nor the selling stockholders have authorized anyone to provide you with any information or to make any representations other than those contained in this prospectus or any applicable prospectus supplement or any free writing prospectuses prepared by or on behalf of us or to which we have referred you. Neither we nor the selling stockholders take responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. Neither we nor the selling stockholders will make an offer to sell these securities in any jurisdiction where such offer or sale is not permitted. No dealer, salesperson or other person is authorized to give any information or to represent anything not contained in this prospectus, any applicable prospectus supplement or any related free writing prospectus. You should assume that the information appearing in this prospectus or any prospectus supplement is accurate as of the date on the front of those documents only, regardless of the time of delivery of this prospectus or any applicable prospectus supplement, or any sale of a security. Our business, financial condition, results of operations and prospects may have changed since those dates.

The selling stockholders and their permitted transferees may use this prospectus to sell securities from time to time through any means described in the section titled “Plan of Distribution.” More specific terms of any securities that the selling stockholders and their permitted transferees offer and sell may be provided in a prospectus supplement that describes, among other things, the specific amounts and prices of the securities being offered and the terms of the offering.

We may also provide a prospectus supplement or post-effective amendment to the registration statement to add information to, or update or change information contained in, this prospectus. Any statement contained in this prospectus will be deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained in such prospectus supplement or post-effective amendment modifies or supersedes such statement. Any statement so modified will be deemed to constitute a part of this prospectus only as so modified, and any statement so superseded will be deemed not to constitute a part of this prospectus. You should read both this prospectus and any applicable prospectus supplement or post-effective amendment to the registration statement together with the additional information to which we refer you in the section of this prospectus titled “Where You Can Find More Information.”

This prospectus contains summaries of certain provisions contained in some of the documents described herein, but reference is made to the actual documents for complete information. All of the summaries are qualified in their entirety by the actual documents. Copies of some of the documents referred to herein have been filed, will be filed or will be incorporated by reference as exhibits to the registration statement of which this prospectus is a part, and you may obtain copies of those documents as described below under “Where You Can Find More Information.”

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WHERE YOU CAN FIND MORE INFORMATION

We have filed with the SEC this Post-Effective Amendment No. 3, including exhibits, under the Securities Act, with respect to the class A common stock described in this prospectus. This prospectus, which constitutes a part of the registration statement, does not contain all of the information set forth in the registration statement, some of which is contained in exhibits to the registration statement as permitted by the rules and regulations of the SEC. For further information with respect to us and our class A common stock, we refer you to the registration statement, including the exhibits filed as a part of the registration statement. Statements contained in this prospectus concerning the contents of any contract or any other document are not necessarily complete. If a contract or document has been filed as an exhibit to the registration statement, please see the copy of the contract or document that has been filed. Each statement in this prospectus relating to a contract or document filed as an exhibit is qualified in all respects by the filed exhibit. You may obtain copies of this information by mail from the public reference room of the SEC at 100 F Street, N.E., Washington, D.C. 20549, at prescribed rates. Please call the SEC at 1-800-SEC-0330 for more information about the operation of the Public Reference Room. The SEC also maintains an Internet website that contains reports, proxy and information statements and other information regarding issuers, like us, that file electronically with the SEC. The address of that website is http://www.sec.gov.

We are subject to the informational requirements of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and, in accordance with the Exchange Act, file reports, proxy and information statements and other information with the SEC. Such annual, quarterly and special reports, proxy and information statements and other information can be inspected and copied at the locations set forth above. We make available free of charge on or through our website, www.greenidge.com, our filings with the SEC pursuant to Sections 13(a) or 15(d) of the Exchange Act as soon as reasonably practicable after we electronically file such material with, or furnish it to, the SEC. We make our website content available for information purposes only. Information contained on, or accessible through, our website is not incorporated by reference into this prospectus and does not constitute a part of this prospectus.

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DOCUMENTS INCORPORATED BY REFERENCE

The SEC allows us to “incorporate by reference” certain of the information that we file with it after the date of the filing of the registration statement of which this prospectus forms a part, which means that we can disclose important information to you by referring you to the documents containing that information. The information incorporated by reference is considered to be part of this prospectus, and later information that we file with the SEC will automatically update and supersede this information.

The documents listed below and any future filings made by us with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act (excluding any information furnished pursuant to Item 2.02 or Item 7.01 on any Current Report on Form 8-K and exhibits filed on such form that are related to such items unless such Form 8-K expressly provides to the contrary), including all such documents we may file with the SEC after the date on which the registration statement that includes this prospectus was initially filed with the SEC and prior to the effectiveness of the registration statement and all such documents we may file with the SEC after the effectiveness of the registration statement, are incorporated by reference in this prospectus until the termination of the offering under this registration statement:

We will provide a copy of these filings (including certain exhibits that are specifically incorporated by reference therein) to each person, including any beneficial owner, to whom a prospectus is delivered. You may request a copy of any or all of these filings at no cost, by writing or calling us at:

Greenidge Generation Holdings Inc.

Attention: Investor Relations

135 Rennell Drive, 3rd Floor

Fairfield, CT 06890

(203) 718-5960

Copies of certain information filed by us with the SEC, including our Annual Report and Quarterly Reports, are also available on our website at www.greenidge.com. Information contained on our website or accessible through our website is not incorporated by reference herein.

You should read the information relating to us in this prospectus together with the information in the documents incorporated by reference. Nothing contained herein shall be deemed to incorporate information furnished, but not filed, with the SEC.

iv

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

This prospectus and the documents incorporated or deemed to be incorporated by reference herein include certain statements that may constitute “forward-looking statements” within the meaning of Section 27A of the Securities Act, Section 21E of the Exchange Act and Private Securities Litigation Reform Act of 1995 (the “PSLRA”). 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. As used herein, “we,” “us,” “our” and “Greenidge” and the “Company” refer to Greenidge Generation Holdings Inc. together with its consolidated subsidiaries.

Consequently, all of the forward-looking statements made in this prospectus are qualified by the information contained herein, including the information contained under this caption and the information under the section “Risk Factors” in our most recent Annual Report on Form 10-K filed with the SEC, as supplemented by our Quarterly Reports on Form 10-Q, and discussed elsewhere in this prospectus, each prospectus supplement and in the documents incorporated by reference in this prospectus and each prospectus supplement. 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, whether written or oral, that may be made from time to time, whether as a result of new information, future events or otherwise, except as may be required by law.

You should not put undue reliance on forward-looking statements. No assurances can be given 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 prospectus. All forward-looking statements speak only as of the date of this prospectus and 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.

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RISK FACTORS

An investment in our securities involves a high degree of risk. You should carefully read and consider all of the risks described in the “Risk Factors” section of our Annual Report on Form 10-K for the year ended December 31, 2021, our Quarterly Report on Form 10-Q for the quarter ended June 30, 2022 and other subsequent filings made with the SEC, which are incorporated by reference into this prospectus.

The risks and uncertainties incorporated by reference into this prospectus are not the only ones we face. Additional risks and uncertainties not presently known or which we consider immaterial as of the date hereof may also have an adverse effect on our business. If any of the matters discussed in the risk factors incorporated by reference were to occur, our financial condition, business and results of operations (including cash flows) may be materially adversely affected. In that event, the market price of our class A common stock could decline, and you could lose all or part of your investment. Please read “Cautionary Statement Regarding Forward-Looking Statements.”

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USE OF PROCEEDS

We will not receive any proceeds from the sale of class A common stock by the selling stockholders. The selling stockholders will pay any underwriting discounts and commissions and expenses incurred by them for brokerage, accounting, tax or legal services or any other expenses incurred by them in disposing of the shares. We will bear all other costs, fees and expenses incurred in effecting the registration of the shares covered by this prospectus, including, without limitation, all registration and filing fees and fees and expenses of our counsel and our accountants.

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DIVIDEND POLICY

We have never declared or paid cash dividends on our capital stock. Our policy is to retain all earnings, if any, to provide funds for the operation and expansion of our business and we do not anticipate paying any cash dividends in the foreseeable future. The declaration of dividends, if any, will be subject to the discretion of our board, which may consider such factors as our results of operations, financial condition, capital needs and acquisition strategy, among others. Under the Amended and Restated Bridge Promissory Note, dated August 10, 2022, by and between the Company and B. Riley Commercial Capital, LLC, that matures on June 20, 2023, the Company is restricted from paying dividends.

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SELLING STOCKHOLDERS

The following table was prepared based on information provided to us by the selling stockholders. It sets forth the name and address of the selling stockholders, the aggregate number of shares of common stock that the selling stockholders may offer pursuant to this prospectus, and the beneficial ownership of the selling stockholders both before and after the offering.

We have determined beneficial ownership in accordance with the rules of the SEC. Except as indicated by the footnotes below, we believe, based on the information furnished to us, that the persons and entities named in the table below have sole voting and investment power with respect to all shares that they beneficially own, subject to applicable community property laws. Unless otherwise indicated in the footnotes below, based on the information provided to us by or on behalf of the selling stockholders, no selling stockholder is a broker-dealer or an affiliate of a broker-dealer.

For purposes of computing percentage ownership after this offering, we have assumed that all class B common stock held by the selling stockholders will be converted to class A common stock and sold in this offering. In computing the number of shares beneficially owned by a person and the percentage ownership of that person, we have deemed to be outstanding all common stock subject to options, warrants or other convertible securities held by that person or entity that are currently exercisable or releasable or that will become exercisable or releasable within 60 days of September 30, 2022. We did not deem these shares outstanding, however, for the purpose of computing the percentage ownership of any other person.

Unless otherwise indicated, the address of each person listed in the table below is c/o Greenidge, 135 Rennell Drive, 3rd Floor Fairfield, CT 06890.

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We do not currently have any arrangements which, if consummated, may result in a change of control of Greenidge.

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SECURITIES ACT RESTRICTIONS ON RESALE OF SECURITIES

Rule 144

Pursuant to Rule 144 under the Securities Act (“Rule 144”), a person who has beneficially owned restricted shares of our class A common stock or our warrants for at least six months would be entitled to sell their securities provided that (1) such person is not deemed to have been an affiliate of us at the time of, or at any time during the three months preceding, a sale and (2) we are subject to the Exchange Act periodic reporting requirements for at least three months before the sale and have filed all required reports under Section 13 or 15(d) of the Exchange Act during the 12 months (or such shorter period as we were required to file reports) preceding the sale.

Persons who have beneficially owned restricted shares of our class A common stock or our warrants for at least six months but who are affiliates of us at the time of, or at any time during the three months preceding, a sale, would be subject to additional restrictions, by which such person would be entitled to sell within any three- month period only a number of securities that does not exceed the greater of:

Sales by our affiliates under Rule 144 are also limited by manner of sale provisions and notice requirements and to the availability of current public information about us.

Form S-8 Registration Statement

We filed a registration statement on Form S-8 under the Securities Act to register the shares of our class A common stock issued or issuable under the 2021 Plan. Such Form S-8 registration statement became effective automatically upon filing. The shares of our class A common stock issued or issuable under the 2021 Plan can be sold in the public market upon issuance, subject to applicable restrictions.

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MATERIAL U.S. FEDERAL TAX CONSIDERATIONS FOR NON-U.S. HOLDERS OF OUR COMMON STOCK

The following is a summary of the material U.S. federal income and estate tax consequences of the ownership and disposition of our common stock. This summary is limited to Non-U.S. Holders (as defined below) that hold our common stock as a capital asset (generally, property held for investment) for U.S. federal income tax purposes. This summary does not discuss all of the aspects of U.S. federal income and estate taxation that may be relevant to a Non-U.S. Holder in light of the Non-U.S. Holder’s particular investment or other circumstances. Accordingly, all prospective Non-U.S. Holders should consult their own tax advisors with respect to the U.S. federal, state, local and non-U.S. tax consequences of the purchase, ownership and disposition of our common stock.

This summary is based on provisions of the Internal Revenue Code of 1986, as amended (the “Code”), applicable U.S. Treasury regulations and administrative and judicial interpretations, all as in effect or in existence on the date of this prospectus. Subsequent developments in U.S. federal income or estate tax law, including changes in law or differing interpretations, which may be applied retroactively, could alter the U.S. federal income and estate tax consequences of owning and disposing of our common stock as described in this summary. There can be no assurance that Internal Revenue Service (the “IRS”) will not take a contrary position with respect to one or more of the tax consequences described herein and we have not obtained, nor do we intend to obtain, a ruling from the IRS with respect to the U.S. federal income or estate tax consequences of the purchase, ownership or disposition of our common stock.

As used in this summary, the term “Non-U.S. Holder” means a beneficial owner of our common stock that is not, for U.S. federal income tax purposes:

If an entity or arrangement treated as a partnership for U.S. federal income tax purposes holds our common stock, the tax treatment of a partner in such a partnership generally will depend upon the status of the partner, the activities of the partnership and certain determinations made at the partner level. Partnerships, and partners in partnerships, that hold common stock should consult their own tax advisors as to the particular U.S. federal income and estate tax consequences of purchasing, owning and disposing of our common stock that are applicable to them.

This summary does not consider any specific facts or circumstances that may apply to a Non-U.S. Holder and does not address any special tax rules that may apply to particular Non-U.S. Holders, such as:

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In addition, this summary does not address any U.S. state or local, or non-U.S. or other tax consequences, or any U.S. federal income or estate tax consequences for beneficial owners of a Non-U.S. Holder, including stockholders of a controlled foreign corporation or passive foreign investment company that holds common stock.

THIS DISCUSSION IS FOR INFORMATIONAL PURPOSES ONLY AND IS NOT TAX ADVICE. INVESTORS SHOULD CONSULT THEIR TAX ADVISORS WITH RESPECT TO THE APPLICATION OF THE U.S. FEDERAL INCOME TAX LAWS TO THEIR PARTICULAR SITUATIONS, AS WELL AS ANY TAX CONSEQUENCES OF THE PURCHASE, OWNERSHIP, AND DISPOSITION OF OUR COMMON STOCK ARISING UNDER THE U.S. FEDERAL ESTATE OR GIFT TAX LAWS OR UNDER THE LAWS OF ANY STATE, LOCAL OR NON-U.S. TAXING JURISDICTION OR UNDER ANY APPLICABLE INCOME TAX TREATY.

Distributions on Our Common Stock

We do not currently expect to pay any cash dividends on our common stock. If we make distributions of cash or property (other than certain pro rata distributions of common stock) with respect to our common stock, any such distributions generally will constitute dividends for U.S. federal income tax purposes to the extent paid from our current or accumulated earnings and profits, as determined under U.S. federal income tax principles and will be subject to withholding tax at a 30% rate or such lower rate as may be specified by an applicable income tax treaty. A Non-U.S. Holder who claims the benefit of an applicable income tax treaty between the United States and such holder’s country of residence generally will be required to provide a properly executed IRS Form W-8BEN or W-8BEN-E (or successor form) and satisfy applicable certification and other requirements. A Non-U.S. Holder that is eligible for a reduced rate of U.S. withholding tax under an income tax treaty may generally obtain a refund or credit of any excess amounts withheld by timely filing an appropriate claim with the IRS. Non-U.S. Holders are urged to consult their tax advisors regarding their entitlement to benefits under a relevant income tax treaty.

Dividends that are treated as effectively connected with a trade or business conducted by a Non-U.S. Holder within the United States and, if an applicable income tax treaty so provides, that are attributable to a permanent establishment or a fixed base maintained by the Non-U.S. Holder within the United States are generally exempt from the 30% withholding tax if the Non-U.S. Holder satisfies applicable certification and disclosure requirements. However, such U.S. effectively connected income is taxed on a net income basis at the same U.S. federal income tax rates applicable to United States persons (as defined in the Code). Any U.S. effectively connected income received by a Non-U.S. Holder that is a corporation may also, under certain circumstances, be subject to an additional “branch profits tax” at a 30% rate or such lower rate as may be specified by an applicable income tax treaty between the United States and such holder’s country of residence.

If the amount of a distribution exceeds our current and accumulated earnings and profits, such excess first will be treated as a tax-free return of capital to the extent of a Non-U.S. Holder’s adjusted tax basis in its shares of our common stock, and thereafter will be treated as capital gain from a disposition of common stock subject to the tax treatment described below in “ —Dispositions of Our Common Stock.”

The foregoing discussion is subject to the discussions below under “ —Backup Withholding and Information Reporting” and “ —FATCA Withholding.”

Dispositions of Our Common Stock

We believe that we may be a “United States real property holding corporation.” Generally, a corporation is a United States real property holding corporation if the fair market value of its United States real property interests equals or exceeds 50% of the sum of the fair market value of its worldwide real property interests and its other assets used or held for use in a trade or business. Notwithstanding our potential status as a “United States real property holding corporation,” a Non-U.S. Holder generally will not be subject to U.S. federal income tax (including U.S. withholding tax) on gain recognized on any sale or other disposition of our common stock unless:

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The foregoing discussion is subject to the discussions below under “ —Backup Withholding and Information Reporting” and “ —FATCA Withholding.”

Federal Estate Tax

Our common stock that is owned (or treated as owned) by an individual who is not a U.S. citizen or resident of the United States (as specially defined for U.S. federal estate tax purposes) at the time of death will be included in the individual’s gross estate for U.S. federal estate tax purposes, unless an applicable estate tax or other treaty provides otherwise and, therefore, may be subject to U.S. federal estate tax.

Backup Withholding and Information Reporting

Generally, distributions in respect of our common stock to a Non-U.S. Holder and the amount of any tax withheld from such payments must be reported annually to the IRS and to the Non-U.S. Holder. Copies of these information returns may be made available by the IRS to the tax authorities of the country in which the Non-U.S. Holder is a resident under the provisions of an applicable income tax treaty. Under certain circumstances, backup withholding of U.S. federal income tax may apply to distributions in respect of our common stock to a Non-U.S. Holder if the Non-U.S. Holder fails to certify under penalties of perjury that it is not a United States person.

Payments of the proceeds of the sale or other disposition of our common stock to or through a foreign office of a U.S. broker or of a foreign broker with certain specified U.S. connections will be subject to information reporting requirements, but generally not backup withholding, unless (i) the broker has evidence in its records that the payee is not a United States person, and the broker has no actual knowledge or reason to know to the contrary or (ii) the payee otherwise establishes an exemption. Payments of the proceeds of a sale or other disposition of our common stock to or through the U.S. office of a broker will be subject to information reporting and backup withholding unless the payee certifies under penalties of perjury that it is not a United States person (and the payor has no actual knowledge or reason to know to the contrary) or otherwise establishes an exemption.

Any amount withheld under the backup withholding rules generally will be allowed as a refund or credit against a Non-U.S. Holder’s U.S. federal income tax liability (if any); provided that the required information is timely furnished to the IRS. Non-U.S. Holders should consult their tax advisors about the filing of a U.S. federal income tax return in order to obtain a refund.

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FATCA Withholding

Non-U.S. Holders should be aware that, under Sections 1471 through 1474 of the Code (“FATCA”), a 30% withholding tax will be imposed on certain payments (which could include distributions in respect of our common stock) to a foreign entity if such entity fails to satisfy certain disclosure and reporting rules that in general require that (i) in the case of a foreign financial entity, the entity or a related entity register with the IRS and identify and provide information in respect of financial accounts with such entity held (directly or indirectly) by United States persons and United States owned foreign entities, and (ii) in the case of a non-financial foreign entity, the entity identify and provide information in respect of substantial United States owners of such entity. Foreign entities that hold our common stock generally will be subject to this tax unless they certify on an applicable IRS Form W-8 (generally, IRS Form W-8BEN-E) that they comply with, or are deemed to comply with, or are exempted from the application of, these rules.

Various requirements and exceptions are provided under FATCA and additional requirements and exceptions may be provided in subsequent guidance. Further, the United States has entered into many intergovernmental agreements (“IGAs”) with foreign governments relating to the implementation of, and information sharing under, FATCA and such IGAs may alter one or more of the FATCA information reporting rules.

Under certain circumstances, a Non-U.S. Holder might be eligible for refunds or credits of such taxes. Holders are encouraged to consult with their tax advisors regarding the possible implications of FATCA on their investment in our common stock.

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PLAN OF DISTRIBUTION

The selling stockholders and any of their pledgees, donees, transferees, assignees and successors-in-interest may, from time to time, sell any or all of their shares of our class A common stock on any stock exchange, market or trading facility on which the shares are traded or quoted or in private transactions. These sales may be at fixed or negotiated prices. The selling stockholders may use any one or more of the following methods when selling shares:

The selling stockholders may also sell shares under Rule 144 of the Securities Act, if available, rather than under this prospectus. The selling stockholders shall have the sole and absolute discretion not to accept any purchase offer or make any sale of shares if it deems the purchase price to be unsatisfactory at any particular time.

The selling stockholders or their respective pledgees, donees, transferees or other successors in interest, may also sell the shares directly to market makers acting as principals and/or broker-dealers acting as agents for themselves or their customers. Such broker-dealers may receive compensation in the form of discounts, concessions or commissions from the selling stockholders and/or the purchasers of shares for whom such broker- dealers may act as agents or to whom they sell as principal or both, which compensation as to a particular broker- dealer might be in excess of customary commissions. Market makers and block purchasers purchasing the shares will do so for their own account and at their own risk. It is possible that a selling stockholder will attempt to sell shares of our class A common stock in block transactions to market makers or other purchasers at a price per share which may be below the then existing market price. We cannot assure that all or any of the shares offered in this prospectus will be issued to, or sold by, the selling stockholders. The selling stockholders and any brokers, dealers or agents, upon effecting the sale of any of the shares offered in this prospectus, may be deemed to be “underwriters” as that term is defined under the Securities Act, the Exchange Act and the rules and regulations of such acts. In such event, any commissions received by such broker-dealers or agents and any profit on the resale of the shares purchased by them may be deemed to be underwriting commissions or discounts under the Securities Act.

We are required to pay all fees and expenses incident to the registration of the shares, including fees and disbursements of counsel to the selling stockholders, but excluding brokerage commissions or underwriter discounts.

The selling stockholders, alternatively, may sell all or any part of the shares offered in this prospectus through an underwriter. The selling stockholders have not entered into any agreement with a prospective underwriter and there is no assurance that any such agreement will be entered into.

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The selling stockholders may pledge their shares to their brokers under the margin provisions of customer agreements. If a selling stockholder defaults on a margin loan, the broker may, from time to time, offer and sell the pledged shares. The selling stockholders and any other persons participating in the sale or distribution of the shares will be subject to applicable provisions of the Exchange Act, and the rules and regulations under such act, including, without limitation, Regulation M. These provisions may restrict certain activities of, and limit the timing of purchases and sales of any of the shares by, the selling stockholders or any other such person. In the event that any of the selling stockholders are deemed an affiliated purchaser or distribution participant within the meaning of Regulation M, then the selling stockholders will not be permitted to engage in short sales of our class A common stock. Furthermore, under Regulation M, persons engaged in a distribution of securities are prohibited from simultaneously engaging in market making and certain other activities with respect to such securities for a specified period of time prior to the commencement of such distributions, subject to specified exceptions or exemptions. In addition, if a short sale is deemed to be a stabilizing activity, then the selling stockholders will not be permitted to engage in a short sale of our class A common stock. All of these limitations may affect the marketability of the shares.

If a selling stockholder notifies us that it has a material arrangement with a broker-dealer for the resale of class A common stock, then we would be required to amend the registration statement of which this prospectus is a part, and file a prospectus supplement to describe the agreements between the selling stockholder and the broker-dealer.

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LEGAL MATTERS

The validity of the class A common stock covered by this prospectus will be passed upon by Shearman & Sterling LLP. An investment vehicle comprised of certain partners of Shearman & Sterling LLP, members of their families and other related persons has an interest in us representing less than 0.25% of our aggregate capital stock.

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EXPERTS

Our consolidated financial statements as of and for the years ended December 31, 2021 and 2020 incorporated by reference herein, have been audited by Armanino LLP, an independent registered public accounting firm, as set forth in their report, incorporated by reference herein, and are included in reliance upon such report given on the authority of such firm as experts in accounting and auditing.

The consolidated financial statements of Support.com as of and for the years ended December 31, 2020 and 2019 incorporated by reference herein, have been audited by Plante & Moran, PLLC, an independent registered public accounting firm, as set forth in their report, incorporated by reference herein, and are included in reliance upon such report given on the authority of such firm as experts in accounting and auditing.

25

Greenidge Generation Holdings Inc.

10,458,474 Shares of

Class A Common Stock

PROSPECTUS

October 6, 2022