Sec Form 3 Filing - Howell Stephen Mitchell Jr. @ Riot Platforms, Inc. - 2024-06-01

FORM 3 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Howell Stephen Mitchell Jr. 2. Issuer Name and Ticker or Trading Symbol Riot Platforms, Inc. [ RIOT] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) COO (See Remarks) (Last) (First) (Middle) 3. Date of Earliest Transaction (MM/DD/YY) 06/01/2024 (Street) CASTLE ROCK, CO80109 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 75,507 ( 1 ) D Common Stock 24,643 ( 2 ) D Common Stock 349,284 ( 3 ) D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Howell Stephen Mitchell Jr. CASTLE ROCK, CO80109 COO (See Remarks) Signatures /s/ Alexander K. Travis, Attorney-in-Fact for Stephen Howell 06/11/2024 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Shares of the Issuer's common stock, no par value per share, ("Common Stock") acquired pursuant to vested equity awards granted to the Reporting Person under the Issuer's 2019 Equity Incentive Plan, as amended, (the "Equity Plan") in connection with the Reporting Person's service with the Issuer, which vested in accordance with the terms of equity award agreements between the Issuer and the Reporting Person under the Equity Plan (each, an "Award Agreement"). All awards of equity compensation granted under the Equity Plan are authorized by the Compensation and Human Resources Committee (the "Committee") of the Issuer's Board of Directors, which administers the Equity Plan. ( 2 )Represents the outstanding, unvested portion of service-based restricted stock awards ("RSAs") granted to the Reporting Person under the Equity Plan pursuant to the Long-Term Incentive Compensation Program established by the Committee under the Equity Plan as of July 13, 2023 (the "LTIP"), as compensation for the Reporting Person's service with the Issuer. As set forth in the applicable Award Agreement, these RSAs are eligible to vest, if at all, in three (3) approximately equal annual tranches as of July 1, 2024, 2025, and 2026, subject and pursuant to the Reporting Person's continued service with the Issuer through the applicable vesting dates. Any RSAs remaining unvested as of the end of the Reporting Person's service with the Issuer shall be automatically forfeited and returned to the Issuer, without consideration. ( 3 )Represents the outstanding, unvested portion of performance-based restricted stock awards ("PRSAs") granted to the Reporting Person under the Equity Plan pursuant to the LTIP, as compensation for the Reporting Person's service with the Issuer. The reported shares represents 200% of the target award of 174,642 shares granted to the Reporting Person under the LTIP, which is the maximum performance award achievable during the performance period ending December 31, 2025. The PRSAs are eligible to vest, if at all, based upon Issuer's achievement of certain performance objectives established by the Committee during the performance period as certified by the Committee as of the vesting date, July 31, 2026, subject to the Reporting Person's continued service with the Issuer. Any PRSAs remaining unvested as of the earlier of the end of the Reporting Person's service with the Issuer or July 31, 2026, shall be automatically forfeited and returned to the Issuer, without consideration.

Remarks: Effective as of June 1, 2024, the Reporting Person was appointed to serve as the Issuer's Chief Operating Officer ("COO").

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

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