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:

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 of our series A preferred stock listed on Schedule A thereto 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 April 8, 2022, the closing sale price of our common stock as reported by The Nasdaq Global Select Market was $8.54.

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 11 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 April 11, 2022

TABLE OF CONTENTS

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement on Form S-1 that we filed with the SEC using the “shelf” registration process. Under the shelf registration process, the selling stockholders may, from time to time, sell the securities offered by them 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 or incorporated by reference into this prospectus or any applicable prospectus supplement. 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 are not permitted. No dealer, salesperson or other person is authorized to give any information or to represent anything not contained in or incorporated by reference into this prospectus or any applicable prospectus supplement. You should not assume that the information contained in or incorporated by reference in this prospectus is accurate as of any date other than their respective dates. 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 together with the other information contained or incorporated by reference in this prospectus and any applicable prospectus supplement or post-effective amendment to the registration statement.

For further information about our business and the securities covered by this prospectus, you should refer to the registration statement and its exhibits. The exhibits to our registration statement contain the full text of certain contracts and other important documents we have summarized in this prospectus. Since these summaries may not contain all the information that you may find important in deciding whether to purchase our securities, you should review the full text of these documents. See “Where You Can Find More Information” and “Incorporation of Certain Information by Reference” for more information.

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 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. As used herein, “we,” “us,” “our” and “Greenidge” refer to Greenidge Generation Holdings Inc. together with its consolidated subsidiaries.

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 the section “Risk Factors” of this prospectus and in the documents incorporated by reference in this prospectus, as well as statements about or relating to or otherwise affected by:

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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” of this prospectus and in the documents incorporated by reference in this prospectus. 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.

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 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.

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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 Bridge Promissory Note entered into in March 2022 that matures on July 20, 2022, subject to up to five 30-day extensions that may be elected by the Company, 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 April 11, 2022. We did not deem these shares outstanding, however, for the purpose of computing the percentage ownership of any other person. See descriptions of our securities in more detail below under “Description of Securities.”

Unless otherwise indicated, the address of each person listed in the table below is c/o Greenidge, 135 Rennell Drive, 3^rd 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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DESCRIPTION OF SECURITIES

The following is a summary of the terms of our securities. This summary does not purport to be complete, nor does it represent all information which you might find to be important for understanding our capital stock. This summary is subject to, and qualified in its entirety by reference to, our amended and restated certificate of incorporation and bylaws, copies of which are filed as exhibits to the registration statement of which this prospectus forms a part.

General

On September 13, 2021, we filed an amendment to our certificate of incorporation to increase our authorized capital stock. Following the amendment, our authorized capital stock consists of 2,400,000,000 shares of class A common stock, par value $0.0001 per share, 600,000,000 shares of class B common stock, par value $0.0001 per share, and 20,000,000 shares of preferred stock, par value $0.0001 per share.

The number of authorized shares of our common or preferred stock may be increased or decreased by the affirmative vote of the holders of shares of our capital stock representing a majority of the votes represented by all outstanding shares of such capital stock entitled to vote on such matter, irrespective of the provisions of Section 242(b)(2) of General Corporation Law of the State of Delaware (the “DGCL”), in addition to any vote of the holders of one or more series of our preferred stock that may be required by the terms of such preferred stock. However, the number of authorized shares of common or preferred stock to be decreased may not be decreased below the number of shares thereof then outstanding or, in the case of class A common stock, the number of such shares reserved for issuance upon conversion into shares of class A common stock of the then-outstanding shares of class B common stock.

Common Stock

As of April 11, 2022, there were 12,836,565 shares of class A common stock and 28,526,372 shares of class B common stock issued and outstanding. All shares of our common stock now outstanding are duly authorized, fully paid and non-assessable. Shares of class B common stock that have been acquired by us, whether by repurchase, upon conversion or otherwise, are retired and not issuable again as shares of class B common stock. Below is a summary of the rights of the common stock.

Voting Rights. The holders of class A common stock are entitled to one (1) vote per share, and the holders of class B common stock are entitled to ten (10) votes per share at all stockholder meetings and on all matters submitted to our stockholders generally. The holders of class A common stock and class B common stock vote together as a single class, unless specifically provided in the amended and restated certificate of incorporation or otherwise required by law. The DGCL could require holders of class A common stock or class B common stock, as the case may be, to vote separately as a single class if we were to seek to amend our amended and restated certificate of incorporation either (i) to increase or decrease the par value of a class of stock, or (ii) in a manner that alters or changes the powers, preferences or special rights of a class of stock in a manner that affected its holders adversely.

Holders of class A common stock and class B common stock are not allowed to vote on any amendment of our amended and restated certificate of incorporation that relates only to the terms of a series of outstanding preferred stock for which the holders of such affected preferred stock have the right to vote under the certificate of incorporation or the DGCL.

Stockholders do not have the ability to cumulate votes for the election of directors.

Dividend Rights. Subject to preferences that may apply to shares of preferred stock outstanding at the time, the holders of outstanding shares of our common stock are entitled to receive dividends out of assets legally available if our board of directors, in its discretion, determines to issue dividends and only then at the times and in the amounts that the board of directors may determine. If a dividend is paid in the form of shares of class A common

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stock or class B common stock, then the holders of class A common stock shall be entitled to receive shares of class A common stock, and holders of class B common stock shall be entitled to receive shares of class B common stock, with holders of shares of class A common stock and class B common stock receiving, on a per share basis, an identical number of shares of class A common stock or class B common stock, as applicable. The foregoing sentence also applies should the dividend be paid in rights to acquire, or securities convertible into or exchangeable for, class A and class B common stock. However, upon the approval by the affirmative vote of the holders of a majority of the outstanding shares of class A common stock and class B common stock, each voting separately as a class, our board may pay or make a disparate dividend per share of class A common stock or class B common stock (whether in the amount of such dividend payable per share, the form in which such dividend is payable, the timing of the payment, or otherwise).

Right to Receive Liquidation Distributions. Upon our dissolution, liquidation or winding-up, the assets legally available for distribution to our stockholders are distributable ratably among the holders of common stock, subject to prior satisfaction of all outstanding debt and liabilities and the preferential rights and payment of liquidation preferences, if any, on any outstanding shares of preferred stock.

Conversion. Each share of class B common stock is convertible into one (1) share of class A common stock at the option of the holder thereof at any time upon written notice to us. In addition, each share of class B common stock shall automatically convert into one (1) share of class A common stock (i) upon any transfer, other than certain transfers to controlled entities or, in the case of individuals, to trusts for estate planning purposes, as more fully described in our certificate of incorporation, of such class B common stock; (ii) upon the date specified by the holders of at least a majority of the then outstanding shares of class B common stock, voting as a separate class; or (iii) on the date that is five (5) years after the date the class A common stock is first registered under Section 12(b) or 12(g) of the Exchange Act.

Other Dual Class Provisions. In general, the class A common stock and class B common stock are to be treated the same as the other and ratably, on a per share basis, in the case of distributions or payments in respect of the common stock, consolidations or mergers of Greenidge, or consideration to be received in a tender or exchange offer. However, in such transactions, the class A and class B common stock are permitted to receive different or disproportionate consideration or distributions (as the case may be) if the per share consideration or distribution in the form of securities issuable to a share of class B common stock has ten (10) times the voting power of securities issuable to a share of class A common stock or if the different or disproportionate consideration or distribution is approved by the affirmative vote of the holders of a majority of the class A common stock and class B common stock, each voting separately as a class.

No Preemptive or Similar Rights. The common stock is not entitled to preemptive rights and is not subject to redemption or sinking fund provisions.

No Ownership Limitations or Transfer Restrictions. The common stock is not subject to any limitation on the amount of securities that may be held by holders, and except for the conversion feature of the class B common stock, the common stock is not by its terms subject to any transfer restrictions.

Conversion Cap with 210 Capital. 210 Capital, LLC (“210 Capital”) is party to an investor agreement with Greenidge, dated as of September 9, 2021 with a conversion cap that provides that the class B common stock issued upon conversion of the shares of series A preferred stock held by 210 Capital may not be converted into class A common stock if, after such conversion, 210 Capital, together with its affiliates and any other person acting together with it and its affiliates, would beneficially own, as determined in accordance with Section 13(d) of the Exchange Act, more than 4.99% or 9.99%, as applicable, of the number of shares of class A common stock then issued and outstanding. 210 Capital may increase or decrease its beneficial ownership limitation upon giving notice to Greenidge, which such increase or decrease will not be effective until the 61^st day after the notice is delivered to Greenidge.

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Preferred Stock

On September 15, 2021, each outstanding share of our series A preferred stock converted into four shares of our class B common stock. Such converted shares of series A preferred stock were automatically retired and cancelled upon such conversion and may not be reissued as series A preferred stock.

Under our amended and restated certificate of incorporation, our board of directors may, without further action by our stockholders, fix the rights, preferences, privileges and restrictions of up to an aggregate of 20,000,000 shares of preferred stock in one or more series and authorize their issuance. These rights, preferences and privileges could include dividend rights, conversion rights, voting rights, terms of redemption, liquidation preferences and the number of shares constituting any series or the designation of such series, any or all of which may be greater than the rights common stock. Any issuance of our preferred stock could adversely affect the voting power of holders of our common stock and the likelihood that such holders would receive dividend payments and payments on liquidation. In addition, the issuance of preferred stock could have the effect of delaying, deferring or preventing a change of control or other corporate action. We currently have no shares of preferred stock outstanding and we have no present plan to issue any shares of preferred stock.

Warrants

As of September 14, 2021, we had outstanding warrants to purchase 344,800 shares of our class A common stock at an exercise price of $6.25 per share. On September 15, 2021, all such warrants were exercised. We currently have no warrants to purchase shares of our class A common stock outstanding.

Anti-takeover Effects of Delaware Law and Charter Provisions

We have elected not to be governed by Section 203 of the DGCL, which prohibits a publicly held Delaware corporation from engaging in a business combination, except under certain circumstances, with an interested stockholder.

Our amended and restated certificate of incorporation and bylaws contain certain provisions that may have anti- takeover effects, making it more difficult for or preventing a third party from acquiring control of Greenidge or changing its board of directors and management.

First, our amended and restated certificate of incorporation provides that at any time when the class A common stock is registered under Section 12(b) or 12(g) of the Exchange Act, we cannot engage in a business combination (as described below) with an interested stockholder (as described below) for a period of three years from the time that the stockholder becomes an interested stockholder. This limitation does not apply if (i) our board has first approved the business combination or transaction by which the stockholder becomes an interested stockholder; (ii) upon consummation of the transaction by which the stockholder becomes an interested stockholder, the interested stockholder owns at least 85% of our then outstanding voting stock, excluding shares owned by persons who are directors and also officers and certain employee stock plans; or (iii) at or subsequent to such time, the business combination is approved by the board of directors and the affirmative vote of at least 66-2/3% of the outstanding voting stock not owned by the interested stockholder at an annual or special meeting of stockholders (not written consent).

An “interested stockholder” is any person, other than Greenidge or a direct or indirect majority-owned Greenidge subsidiary, that owns 15% or more of our outstanding voting stock or is an affiliate or associate of ours and was the owner of 15% or more of our outstanding voting stock at any time in the three years prior to the date on which the determination is sought, and the affiliates and associates of such person. An interested stockholder does not include any stockholder whose ownership exceeds the 15% limitation as the result of an action taken solely by us (but only to the extent that such stockholder does not acquire additional voting stock), nor Atlas Capital Resources L.P., its direct transferees, or their respective affiliates, associates or member of a group under Rule 13d-5 of the Exchange Act. Business combinations prohibited by this provision include (i) a merger or consolidation of

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Greenidge or any direct or indirect majority-owned s Greenidge subsidiary with the interested stockholder or any other entity if the merger or consolidation is caused by the interested stockholder, (ii) any sale, lease, exchange, mortgage, pledge, transfer or other disposition, except proportionately as a stockholder of Greenidge, to or with an interested stockholder (in one or a series of transactions) of assets of Greenidge or any direct or indirect majority-owned Greenidge subsidiary, which assets have an aggregate market value of 10% or more of either the aggregate market value of all our assets on a consolidated basis or of all of our outstanding stock, (iii) any transaction resulting in the issuance or transfer of our stock or subsidiary stock by Greenidge or a direct or indirect wholly-owned subsidiary to the interested stockholder, subject to certain exceptions including exercises or conversion of convertible securities, a merger, or transactions generally with all holders that do not increase the interested stockholder’s proportionate share ownership, (iv) any transaction involving us or any direct or indirect wholly-owned subsidiary with the direct or indirect effect of increasing the interested stockholder’s proportionate share of our stock or convertible securities or any subsidiary (on a non-immaterial basis), or (v) the interested stockholder’s receipt of the benefit of any loan, advance, guarantee, pledge or other financial benefit (other than those expressly permitted) provided by or through us or a director or indirect wholly- owned subsidiary.

Further, our amended and restated certificate of incorporation authorizes our board of directors to issue up to 20,000,000 shares of preferred stock without further stockholder approval. The preferred stock may be issued in one or more series, the terms of which may be determined at the time of issuance by the board of directors without further action by the stockholders. These terms may include preferences as to dividends and liquidation, conversion rights, redemption rights and sinking fund provisions. The issuance of any preferred stock could diminish the rights of holders of common stock, and therefore could reduce the value of such common stock. In addition, specific rights granted to future holders of preferred stock could be used to restrict our ability to merge with, or sell assets to, a third party. The ability of the board of directors to issue preferred stock could make it more difficult, delay, discourage, prevent or make it more costly to acquire or effect a change-in-control, which in turn could prevent stockholders from recognizing a gain in the event that a favorable offer is extended and could materially and negatively affect the market price of class A common stock.

Our amended and restated certificate of incorporation vests solely in the board of directors the authority to establish the number of directors and fill any vacancies and newly created directorships. These provisions will prevent a stockholder from increasing the size of the board of directors and gaining control of the board of directors by filling the resulting vacancies with its own nominees. In addition, our amended and restated certificate of incorporation provide that no member of the board of directors may be removed from office by stockholders without the affirmative vote of the majority in voting power of all of outstanding stock then entitled to vote thereon.

Our bylaws establish an advance notice procedure for stockholder proposals to be brought before an annual meeting of stockholders, including proposed nominations of persons for election to the board of directors. Stockholders at an annual meeting will only be able to consider proposals or nominations specified in the notice of meeting or brought before the meeting by or at the direction of the board of directors or by a stockholder who was a stockholder of record who is entitled to vote at the meeting and who has given timely written notice, in proper form, of the stockholder’s intention to bring that business before the meeting. Although the bylaws do not give the board of directors the power to approve or disapprove stockholder nominations of candidates or proposals regarding other business to be conducted at a special or annual meeting, the bylaws may have the effect of precluding the conduct of certain business at a meeting if the proper procedures are not followed or may discourage or deter a potential acquirer from conducting a solicitation of proxies to elect its own slate of directors or otherwise attempting to obtain control of us.

Furthermore, neither the holders of common stock nor the holders of preferred stock have cumulative voting rights in the election of directors. The combination of the present ownership by a few stockholders of a significant portion of the issued and outstanding common stock and lack of cumulative voting makes it more difficult for other stockholders to replace the board of directors or for a third party to obtain control of us by replacing our board of directors.

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Charter Exclusive Forum Provisions

Our amended and restated certificate of incorporation provides that, unless we consent in writing to the selection of an alternative forum, the Court of Chancery of the State of Delaware shall, to the fullest extent permitted by law, be the sole and exclusive forum for (i) any derivative action or proceeding brought on behalf of us, (ii) any action asserting a claim of breach of a fiduciary duty owed by any of our current or former directors, officers, employees or stockholders to us or our stockholders, (iii) any action asserting a claim arising pursuant to any provision of the DGCL or the amended and restated certificate of incorporation or our amended and restated bylaws or as to which the DGCL confers jurisdiction on the Court of Chancery of the State of Delaware, or (iv) any action asserting a claim governed by the internal affairs doctrine of the laws of the State of Delaware. The Delaware exclusive forum provision described in the foregoing sentence does not apply to actions arising under the Exchange Act or the Securities Act. In this regard, it is noted that Section 27 of the Exchange Act creates exclusive federal jurisdiction over all suits brought to enforce any duty or liability created by the Exchange Act or the rules and regulations promulgated thereunder and, further, that investors cannot waive compliance with the federal securities laws and the rules and regulations thereunder. It is further noted that our amended and restated certificate of incorporation also provides that, unless we consent in writing to the selection of an alternative forum, the U.S. federal district courts shall, to the fullest extent permitted by applicable law, be the exclusive forum for the resolution of any complaint asserting a cause of action arising under U.S. federal securities laws. Although our amended and restated certificate of incorporation contains the federal exclusive forum provision described in the foregoing sentence, it is uncertain whether this provision would apply to actions arising under the Securities Act as it is possible that a court could rule that such provision is inapplicable for a particular claim or action or that such provision is unenforceable, particularly in light of Section 22 of the Securities Act, which creates concurrent jurisdiction for federal and state courts over all suits brought to enforce any duty or liability created by the Securities Act or the rules and regulations promulgated thereunder. Support.com’s governing documents do not contain any exclusive forum provisions.

Transfer Agent

We have appointed Computershare Trust Company, N.A. as the transfer agent for our class A common stock. Its address is 462 South 4^th Street, Suite 1600, Louisville, KY 40202, and its telephone number is +1 (781) 575 3120 or toll free +1 (800) 962 4284.

Listing

Our class A common stock is listed on The Nasdaq Global Select Market under the trading symbol “GREE.”

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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 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.”

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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:

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

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(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.

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 of 1933, as amended (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.

EXPERTS

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.

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.

WHERE YOU CAN FIND MORE INFORMATION

We have filed with the SEC a registration statement on Form S-1 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., Room 1580, Washington, D.C. 20549, at prescribed rates. You may obtain information on the operation of the public reference rooms by calling the SEC at +1 (800) 732 0330. The SEC also maintains an Internet website that contains reports, proxy statements and other information about issuers, like us, that file electronically with the SEC. The address of that website is www.sec.gov.

We are subject to the informational requirements of 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 also make these documents publicly available, free of charge, on our website as soon as reasonably practicable after filing such documents with the SEC. Information on, or accessible through, our website is not part of this prospectus.

INCORPORATION OF CERTAIN INFORMATION 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.

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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.

135 Rennell Drive, 3^rd Floor

Fairfield, CT 06890

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 that can be access 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.

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Greenidge Generation Holdings Inc.

10,458,474 Shares of

Class A Common Stock

PROSPECTUS

April 11, 2022