
PROSPECTUS SUPPLEMENT (To prospectus dated August9, 2024) RIOT PLATFORMS,INC. Up to $500,000,000 ofShares of Common Stock, No Par Value per Share On December30, 2025 we entered into a Sales Agreement (the “Sales Agreement”), with B. RileySecurities, Inc., BTIG, LLC, Cantor Fitzgerald & Co., Keefe, Bruyette & Woods, Inc., Macquarie Capital(USA) Inc., Morgan Stanley & Co. LLC, Needham & Company, LLC, Northland Securities, Inc., andRoth Capital Partners, LLC. (each, a “Sales Agent,” and, collectively, the “Sales Agents”), under which wemay offer and sell from time to time shares of our common stock, no par value per share. Pursuant to thisprospectus supplement, we may sell shares of our common stock having an aggregate initial offering priceof up to $500,000,000, through the Sales Agents, acting as our agents, or directly to the Sales Agents,acting as principals. Our common stock is traded on the Nasdaq Capital Market stock exchange under the Under the Sales Agreement, we will deliver placement notices to the Sales Agents designating the dollaramount or number of shares to be issued and the minimum price per share of our common stock to beoffered, having an aggregate offering price of up to $500,000,000. However, subject to the terms andconditions of the Sales Agreement, the Sales Agents are not required to sell any specific number or dollaramount of our common stock but will act as a sales agent using their commercially reasonable effortsconsistent with their normal sales and trading practices, on mutually agreed terms between us and theSales Agents. We may also instruct the Sales Agents not to sell any common stock if the sales cannot beeffected at or above the price designated in the applicable placement notice. We or any Sales Agent, with In connection with the sale of the common stock on our behalf, each of the Sales Agents may be deemed tobe an “underwriter” within the meaning of the Securities Act of 1933, as amended (the “Securities Act”)and, therefore, the compensation of the Sales Agents would be deemed to be underwriting commissions ordiscounts. Sales of shares of our common stock, if any, under this prospectus supplement may be made byany method permitted by law deemed to be “at the market offerings,” as defined in Rule415 under theSecurities Act, including by means of ordinary brokers’ transactions, to or through a market maker, on orthrough the Nasdaq Capital Market, in the over-the-counter market, in privately negotiated transactions(including block transactions), or through a combination of any such methods of sale. We will pay theSales Agents a commission of up to 1.0% of the gross proceeds from the sale of the shares of our common Investing in our common stock involves a high degree of risk. Before making any investmentdecision regarding our common stock, you should read and carefully consider the risks described inthe section “Risk Factors” on page S-9 of this prospectus supplement and on page 6 of theaccompanying prospectus and any applicable prospectus supplement or free-writing prospectus, aswell as those disclosed in our most recent Annual Report on Form10-K filed with the SEC, as well Neither the SEC nor any state securities commission has approved or disapproved of these securitiesor determined if this prospectus supplement and the accompanying prospectus are truthful or TABLE OF CONTENTS PROSPECTUS SUPPLEMENT PROSPECTUS ABOUT THIS PROSPECTUS SUPPLEMENT This prospectus is in two parts. The first part is this prospectus supplement, which describes the specificterms of this offering of shares of our common stock and certain other matters relating to us. The secondpart is the accompanying prospectus dated August9, 2024, which gives more general information aboutthe securities that we may offer from time to time, some of which does not apply to this offering of sharesof our common stock. Generally, when we refer to this prospectus, we are referring to both this prospectus Except as the context otherwise requires, in this prospectus supplement and the accompanying prospectus,the terms “we,” “us,” “our,” “the Company” and “Riot Platforms” refer to Riot Platforms,Inc. and itsconsolidated subsidiaries. Unless otherwise indicated, all financial data in this prospectus supplement The distribution of this prospectus supplement and the accompanying prospectus and the offering of thecommon stock in certain jurisdictions may be restricted by law. Persons who come into possession of thisprospectus supplement, any related free writing prospectus and the accompanying prospectus shouldinform themselves about and observe any such restrictions. This prospectus supplement, any related freewriting prospectus and the accompanying prospectus do not constitute, and may not be used in connectionwith, an offer or solicitation by anyone in any jurisdiction in which such offer or solicitation is not You should not consider any information in this prospectus supplement, the accompanying prospectus o