Riot Blockchain (RIOT) DEFR14ARevised proxy

Dear Stockholder:

On May 18, 2023, we dismissed Marcum LLP as our independent registered public accounting firm, not as a result of any disagreement on any matter of accounting principles or practices, financial statement disclosure, or audit scope or procedure and appointed Deloitte & Touche (“Deloitte”). We are enclosing herewith Amendment No. 1 to our Definitive Proxy Statement, filed with the U.S. Securities and Exchange Commission (the “SEC”) on May 25, 2023, which amends Proposal No. 2 of our original Definitive Proxy Statement, as filed with the SEC on May 1, 2023, (“Proposal No. 2”) to reflect the substitution of Deloitte and our submission for ratification by our stockholders of such appointment, as well as certain technical amendments to reflect this change in our independent registered public accounting firm. For those stockholders who have previously requested paper copies of our proxy materials, we are also enclosing a new proxy card.

If you have already voted on Proposal No. 2, you may also revoke your original proxy and submit a new proxy by following the instructions outlined on your enclosed Voting Instruction Form.

If you are a stockholder in “street” or “nominee” name, you may revoke your voting instructions and submit new voting instructions by informing the bank, broker or other nominee in accordance with that entity’s procedures for revoking your voting instructions and issuing new instructions. For additional information regarding revoking your proxy, please refer to page 3 of the Definitive Proxy Statement.

IF YOU HAVE ALREADY VOTED YOUR SHARES, REGARDLESS OF HOW YOU HOLD YOUR

SHARES, PLEASE RESUBMIT YOUR VOTE ON PROPOSAL NO. 2.

If you have not yet submitted your proxy, please follow the original instructions on your Notice of Internet Availability of Proxy Materials or return the enclosed new proxy card to submit your vote.

Your vote is important to us. We appreciate your attention to this matter.

By Order of the Board of Directors,

William Jackman

Executive Vice President, General Counsel and Corporate Secretary

Effective May 18, 2023, the Audit Committee of the Board of Directors of Riot Platforms, Inc. (the “Audit Committee” and the “Company” or “Riot”, respectively) notified Marcum LLP (“Marcum”) that Marcum was dismissed as the Company’s independent registered public accounting firm, not as a result of any disagreement on any matter of accounting principles or practices, financial statement disclosure, or audit scope or procedure. As of May 18, 2023, the Audit Committee appointed Deloitte & Touche (“Deloitte”) as the Company’s independent registered public accounting firm for the fiscal year ending December 31, 2023, effective immediately. The Company filed a Current Report on Form 8-K with the U.S. Securities and Exchange Commission (the “SEC”) reporting this change on May 22, 2023.

This Amendment No. 1 to our Definitive Proxy Statement (“Amendment No. 1”) is being filed with the SEC to amend Proposal No. 2 of our original Definitive Proxy Statement, as filed with the SEC on May 1, 2023, (“Proposal No. 2”) to reflect the substitution of Deloitte and our submission for ratification by the Company’s stockholders of such appointment. This Amendment No. 1 amends only those items set forth or described below, and all other items in the Proxy Statement are incorporated herein by reference without changes.

1. All references to Marcum LLP or Marcum in the “Notice of 2023 Annual General Meeting of Stockholders” and the Proxy Statement are amended to read “Deloitte & Touche” or “Deloitte” as appropriate or unless otherwise noted.

2. Proposal No. 2 in the Proxy Statement is amended in its entirety to read as follows:

We are asking our stockholders to ratify the appointment by our Audit Committee of Deloitte, to serve as our independent registered public accounting firm for the fiscal year ending December 31, 2023. Although our Bylaws do not require that our stockholders approve the appointment of our independent registered public accounting firm, the Audit Committee is submitting the selection of Deloitte to our stockholders for ratification at the 2023 Annual General Meeting of Stockholders (the “Annual Meeting”) as a matter of good corporate practice and because we value our stockholders’ views on our independent registered public accounting firm. If our stockholders vote against the ratification of Deloitte, the Audit Committee will consider this in its selection of auditors for the following year. Even if our stockholders ratify the appointment, the Audit Committee may choose to appoint a different independent registered public accounting firm at any time during the year if it is determined that such a change would be in the interest of our Company and our stockholders.

The Audit Committee has retained Deloitte as the Company’s independent registered public accounting firm, to perform the audit of the Company’s consolidated financial statements for the fiscal year ending December 31, 2023, to be included on the Company’s annual report on Form 10-K for the same period. A representative of Deloitte is expected to be present virtually at the Annual Meeting and will have an opportunity to make a statement if he or she desires to do so and will be available to respond to appropriate questions.

On May 18, 2023, the Company dismissed Marcum LLP as its independent registered public accounting firm. The Audit Committee approved the dismissal of Marcum LLP. The Audit Committee previously retained Marcum LLP to serve as the Company’s independent public accounting firm and to perform such audit services for the fiscal years ended December 31, 2018, 2019, 2020, 2021 and 2022.

Except as described below, the reports of Marcum LLP on the financial statements of Riot for the fiscal years ended December 31, 2022 and 2021 did not contain any adverse opinion or disclaimer of opinion and were not qualified or modified as to uncertainty, audit scope or accounting principles. Additionally, during Riot’s fiscal years ended December 31, 2022 and 2021, as well as the subsequent interim periods through May 18, 2023, there were no disagreements within the meaning of Item 304(a)(1)(iv) of Regulation S-K with Marcum LLP on any matter of accounting principles or practices, financial statement disclosure, or auditing scope or procedure, which, if not resolved to Marcum LLP’s satisfaction, would have caused Marcum LLP to make reference to the subject matter of the disagreements in connection with its reports on the Company’s financial statements for such fiscal years.

Effective May 18, 2023, the Company engaged Deloitte as its new independent registered public accounting firm, commencing with the review of the financials for the quarter ending June 30, 2023, as recommended, authorized and approved by the Audit Committee. During the years ended December 31, 2022 and 2021, and the subsequent interim period through May 18, 2023, neither the Company nor anyone on its behalf consulted with Deloitte regarding either (1) the application of accounting principles to a specified transaction regarding us, either completed or proposed, or the type of audit opinion that might be rendered on our financial statements, and no written report or oral advice was provided to the Company that Deloitte concluded was an important factor considered by the Company in reaching a decision as to any accounting, auditing or financial reporting issue, or (2) any matter regarding us that was either the subject of a disagreement (as defined in Item 304(a)(1)(iv) of Regulation S-K and the related instructions) or a reportable event (as defined in Item 304(a)(1)(v) of Regulation S-K).

The Audit Committee current policy requires the Audit Committee’s review and pre-approval of all audit and permissible non-audit services provided by the Company’s independent auditors. These services requiring pre-approval by the Audit Committee may include audit services, audit related services, tax services and other services. All the services performed by the independent registered public accounting firm were approved by the Audit Committee and prior to performance. The Audit Committee has determined that the payments made to its independent accountants for these services are compatible with maintaining such auditors’ independence.

The following table represents aggregate fees billed or expected to be billed for professional services by Marcum LLP for the years ended December 31, 2022 and 2021 in the following categories and amounts were:

All of the services performed in the years ended December 31, 2022 and December 31, 2021 were pre-approved by the Audit Committee. It is the Audit Committee’s policy to pre-approve all audit and permissible non-audit services to be provided to us by our independent registered public accounting firm. Our Audit Committee pre-approves these services by category and service. In addition, the Audit Committee has considered whether the provision of the non-audit services above is compatible with maintaining our independent registered public accounting firm’s independence.

The role of the Audit Committee is, among other things, to assist the Board in its oversight of the following: the integrity of Riot’s financial statements; Riot’s compliance with relevant legal and regulatory requirements; Riot’s internal controls over financial reporting; the qualifications and independence of Riot’s independent registered public accounting firm; and the performance of Riot’s internal audit functions and that of its independent registered public accounting firm.

The Board has determined that, in its business judgment, all members of the Audit Committee are independent within the meaning of the Nasdaq Rules, the Sarbanes-Oxley Act of 2002 and related rules of the SEC.

Riot’s management is responsible for the preparation, presentation and integrity of Riot’s financial statements and the effectiveness of Riot’s system of internal control over financial reporting and disclosure controls and procedures. Management is responsible for maintaining and evaluating appropriate accounting and financial reporting practices and internal controls and procedures designed to ensure compliance with accounting standards and applicable laws and regulations.

The Audit Committee, on behalf of the Company, engaged Marcum LLP (“Marcum”) as its independent registered public accounting firm for the years ended December 31, 2018, 2019, 2020, 2021, and 2022. Pursuant to its appointment, Marcum was responsible for auditing Riot’s consolidated financial statements and expressing an opinion as to whether such financial statements are presented fairly, in all material respects, in conformity with accounting principles generally accepted in the United States. Marcum was also responsible for auditing the effectiveness of Riot’s internal control over financial reporting for the years ended December 31, 2018, 2019, 2021 and 2022. Effective May 18, 2023, the Audit Committee, on behalf of the Company, engaged Deloitte & Touche (“Deloitte”), and dismissed Marcum, for the year ending December 31, 2023. Pursuant to its appointment, Deloitte is now responsible for auditing Riot’s consolidated financial statements and expressing an opinion as to whether such financial statements are presented fairly, in all material respects, in conformity with accounting principles generally accepted in the United States. Deloitte is also now responsible for auditing the effectiveness of Riot’s internal control over financial reporting for the year ending December 31, 2023.

Prior to Marcum’s dismissal, the Audit Committee met and held discussions with the Company’s management and Marcum. The Audit Committee discussed with the Company’s management and Marcum the overall scope of, and plans for, their respective audits and the identification of audit risks. The Audit Committee also met with Marcum, with and without management present, to discuss the results of their respective examinations, the reasonableness of significant judgments, the evaluations of Riot’s internal controls over financial reporting and the overall quality of Riot’s financial reporting. Management has represented to the Audit Committee that Riot’s consolidated financial statements were prepared in accordance with U.S. Generally Accepted Accounting Principles.

In reliance on the reports, reviews and discussions described in this Report, the Audit Committee has recommended to the Board, and the Board has approved, that the audited financial statements be included in Riot’s Annual Report on Form 10-K for the fiscal year ended December 31, 2022, for filing with the SEC and for inclusion in the Company’s proxy materials to be provided to the Company’s stockholders in advance of its annual stockholders’ meeting for the year ending December 31, 2023. The Audit Committee also has appointed, and has requested stockholder ratification of the appointment of, Deloitte as Riot’s new independent registered public accounting firm for the fiscal year ending December 31, 2023.

The affirmative vote of a majority of the votes cast for this proposal is required to ratify the appointment of the Company’s independent registered public accounting firm. Abstentions will be counted towards the tabulation of votes cast on this proposal but will have no effect on the outcome of the vote on this proposal. Brokerage firms have authority to vote customers’ unvoted shares held by the firms in street name on this proposal. If a broker does not exercise this authority, such broker non-votes will have no effect on the results of this vote.

THE BOARD UNANIMOUSLY RECOMMENDS A VOTE FOR THE RATIFICATION OF THE APPOINTMENT OF DELOITTE AS THE COMPANY’S INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM, AND PROXIES SOLICITED BY THE BOARD WILL BE VOTED IN FAVOR THEREOF UNLESS A STOCKHOLDER HAS INDICATED OTHERWISE ON THE PROXY.