This prospectus, including the documents that we incorporate by reference, contains 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”). Such forward-looking statements include those that express plans, anticipation, intent, contingency, goals, targets or future development and/or otherwise are not statements of historical fact. We believe these forward-looking statements are reasonable; however, you should not place undue reliance on any forward-looking statements, which are based on current expectations. These forward-looking statements are based on our current expectations and projections about future events and they are subject to risks and uncertainties known and unknown that could cause actual results and developments to differ materially from those expressed or implied in such statements.

In some cases, you can identify forward-looking statements by terminology, such as “expects,” “anticipates,” “intends,” “estimates,” “plans,” “believes,” “seeks,” “may,” “should,” “could” or the negative of such terms or other similar expressions. Accordingly, these statements involve estimates, assumptions and uncertainties that could cause actual results to differ materially from those expressed in them. Any forward-looking statements are qualified in their entirety by reference to the factors discussed throughout this prospectus. We intend for these forward-looking statements to be covered by the safe harbor provisions for forward-looking statements contained in the Private Securities Litigation Reform Act of 1995, and we are including this statement for purposes of complying with these safe harbor provisions.

You should read this prospectus and the documents that we reference herein and therein and have filed as exhibits to the registration statement, of which this prospectus and any prospectus supplement is part, completely and with the understanding that our actual future results may be materially different from what we expect. You should assume that the information appearing in this prospectus is accurate as of the date on the front cover of this prospectus or such prospectus supplement only. Because the risk factors referred to above, as well as the risk factors incorporated herein by reference, could cause actual results or outcomes to differ materially from those expressed in any forward-looking statements made by us or on our behalf, you should not place undue reliance on any forward-looking statements. Further, any forward-looking statement speaks only as of the date on which it is made, and we undertake no obligation to update any forward-looking statement to reflect events or circumstances after the date on which the statement is made or to reflect the occurrence of unanticipated events, except as may be required under applicable law. New factors emerge from time to time, and it is not possible for us to predict which factors will arise. In addition, we cannot assess the impact of each factor on our business or the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in any forward-looking statements. We qualify all of the information presented in this prospectus and particularly our forward-looking statements, by these cautionary statements.

DESCRIPTION OF COMMON STOCK

General

We are authorized to issue 170,000,000 shares of common stock, at no par value per share.

 Holders of the Company’s common stock are entitled to one vote for each share on all matters submitted to a stockholder vote. Holders of common stock do not have cumulative voting rights. Therefore, holders of a majority of the shares of common stock voting for the election of directors can elect all of the directors. Holders of the Company’s common stock representing a third of the voting power of the Company’s capital stock issued, outstanding and entitled to vote, represented in person or by proxy, are necessary to constitute a quorum at any meeting of stockholders. A vote by the holders of a majority of the Company’s outstanding shares is required to effectuate certain fundamental corporate changes such as liquidation, merger or an amendment to the Company’s certificate of incorporation. 

Holders of the Company’s common stock are entitled to share in all dividends that the board of directors, in its discretion, declares from legally available funds. In the event of a liquidation, dissolution or winding up, each outstanding share entitles its holder to participate pro rata in all assets that remain after payment of liabilities and after providing for each class of stock, if any, having preference over the common stock. The Company’s common stock has no pre-emptive rights, no conversion rights and there are no redemption provisions applicable to the Company’s common stock.

Classified Board of Directors

Our Bylaws provide for our Board to be divided into three classes, with each class serving a staggered three-year term. We believe that a classified board structure, if implemented, would help to ensure the continuity and stability of the Board and our business strategies and policies. The classified board structure could have the effect of making the removal of incumbent directors more time consuming and difficult, and, therefore may discourage a third party from making a tender offer or otherwise attempting to obtain control of us, even though such an attempt might be beneficial to us and our stockholders.

Transfer Agent and Registrar

The transfer agent and registrar for our common stock is Equiniti Trust Company, d/b/a “EQ by Equiniti,” Mendota Heights, Michigan.

Listing 

Our common stock is currently traded on the NASDAQ Capital Market under the symbol “RIOT”.

DESCRIPTION OF PREFERRED STOCK

General

The Company’s articles of incorporation authorize the issuance of 15,000,000 shares of “blank check” preferred stock, no par value per share, in one or more series, subject to any limitations prescribed by law, without further vote or action by the stockholders. Each such series of preferred stock shall have such number of shares, designations, preferences, voting powers, qualifications, and special or relative rights or privileges as shall be determined by our board of directors, which may include, among others, dividend rights, voting rights, liquidation preferences, conversion rights and preemptive rights. 

Preferred stock is available for possible future financings or acquisitions and for general corporate purposes without further authorization of stockholders unless such authorization is required by applicable law, the rules of the NASDAQ Capital Market or other securities exchange or market on which our stock is then listed or admitted to trading. 

Our board of directors may authorize the issuance of preferred stock with voting or conversion rights that could adversely affect the voting power or other rights of the holders of common stock. The issuance of preferred stock, while providing flexibility in connection with possible acquisitions and other corporate purposes could, under some circumstances, have the effect of delaying, deferring or preventing a change in control of the Company. 

A prospectus supplement relating to any series of preferred stock being offered will include specific terms relating to the offering. Such prospectus supplement will include:

The terms, if any, on which the preferred stock may be convertible into or exchangeable for our common stock will also be stated in the preferred stock prospectus supplement. The terms will include provisions as to whether conversion or exchange is mandatory, at the option of the holder or at our option, and may include provisions pursuant to which the number of shares of our common stock to be received by the holders of preferred stock would be subject to adjustment.

Series B Preferred Stock

We have designated 1,750,001 shares of preferred stock as “0% Series B Convertible Preferred Stock.” The shares of Series B Preferred Stock are convertible into shares of common stock based on a conversion calculation equal to the stated value of the Series B Preferred Stock, plus all accrued and unpaid dividends, if any, on such Series B Preferred Stock, as of such date of determination, divided by the conversion price. The stated value of each share of Series B Preferred Stock is $6.80 and the initial conversion price is $6.80 per share, each subject to adjustment for stock splits, stock dividends, recapitalizations, combinations, subdivisions or other similar events.

The holders of Series B Preferred Stock are entitled to receive dividends if and when declared by our board of directors. The Series B Preferred Stock will participate on an “as converted” basis, with all dividends declared on the Company’s common stock. Such dividends will be paid by the Company out of funds legally available therefor, payable, subject to the conditions and other terms hereof, in cash on the stated value of such Series B Preferred Stock.  

We are prohibited from effecting a conversion of the Series B Preferred Stock to the extent that, as a result of such conversion, the holder would beneficially own more than 4.99% percent of the number of shares of common stock outstanding immediately after giving effect to the issuance of shares of common stock upon conversion of the Series B Preferred Stock, which beneficial ownership limitation may be increased by the holder up to, but not exceeding, 9.99% percent. The Series B Preferred Stock contain no voting rights.

The Series B Preferred Stock contains a blocker pursuant to which, if we have not obtained the approval of our stockholders in accordance with NASDAQ Listing Rule 5635(d), then we may not issue upon conversion of the Series B Preferred Stock a number of shares of common stock, which, when aggregated with any other shares of common stock  underlying the Series B Preferred Stock would exceed 19.99% of the shares of common stock issued and outstanding as of the date of exchange agreement between the Company and the holders of the Series B Preferred Stock, subject to adjustment for reverse and forward stock splits, stock dividends, stock combinations and other similar transactions of the common stock.

As of the date of this prospectus, there are 4,199 shares of Series B Convertible Preferred Stock outstanding, convertible into 4,199 shares of common stock which represents less than 1% of the shares of our common stock as of the date of this prospectus.

DESCRIPTION OF WARRANTS

We may issue warrants for the purchase of preferred stock or common stock. Warrants may be issued independently or together with any preferred stock or common stock, and may be attached to or separate from any offered securities. Each series of warrants will be issued under a separate warrant agreement to be entered into between a warrant agent specified in the agreement and us. The warrant agent will act solely as our agent in connection with the warrants of that series and will not assume any obligation or relationship of agency or trust for or with any holders or beneficial owners of warrants. This summary of some provisions of the securities warrants is not complete. You should refer to the securities warrant agreement, including the forms of securities warrant certificate representing the securities warrants, relating to the specific securities warrants being offered for the complete terms of the securities warrant agreement and the securities warrants. The securities warrant agreement, together with the terms of the securities warrant certificate and securities warrants, will be filed with the Securities and Exchange Commission in connection with the offering of the specific warrants. 

The applicable prospectus supplement will describe the following terms, where applicable, of the warrants in respect of which this prospectus is being delivered:

Warrants for the purchase of common stock or preferred stock will be offered and exercisable for U.S. dollars only. Warrants will be issued in registered form only. Upon receipt of payment and the warrant certificate properly completed and duly executed at the corporate trust office of the warrant agent or any other office indicated in the applicable prospectus supplement, we will, as soon as practicable, forward the purchased securities. If less than all of the warrants represented by the warrant certificate are exercised, a new warrant certificate will be issued for the remaining warrants.

Prior to the exercise of any securities warrants to purchase preferred stock or common stock, holders of the warrants will not have any of the rights of holders of the common stock or preferred stock purchasable upon exercise, including in the case of securities warrants for the purchase of common stock or preferred stock, the right to vote or to receive any payments of dividends on the preferred stock or common stock purchasable upon exercise.

DESCRIPTION OF UNITS 

As specified in the applicable prospectus supplement, we may issue units consisting of shares of common stock, shares of preferred stock or warrants or any combination of such securities.

The applicable prospectus supplement will specify the following terms of any units in respect of which this prospectus is being delivered:

RATIO OF EARNINGS TO FIXED CHARGES

If we offer debt securities and/or preference equity securities under this prospectus, we will, if required at that time, provide a ratio of earnings to fixed charges and/or ratio of earnings to combined fixed charges and preference dividends to earnings, respectively, in the applicable prospectus supplement for such offering.

PLAN OF DISTRIBUTION

We may sell the securities offered through this prospectus (i) to or through underwriters or dealers, (ii) directly to purchasers, including our affiliates, (iii) through agents, (iv) via so called “at-the-market” or “ATM” offerings, or (v) through a combination of any of these methods. The securities may be distributed at a fixed price or prices, which may be changed, market prices prevailing at the time of sale, prices related to the prevailing market prices, or negotiated prices. The prospectus supplement will include the following information:

Agents, underwriters, and dealers may be entitled, under agreements entered into with us, to indemnification by us against certain liabilities, including liabilities under the Securities Act. Our agents, underwriters, and dealers, or their affiliates, may be customers of, engage in transactions with or perform services for us, in the ordinary course of business.

Sale through Underwriters or Dealers

Only underwriters named in the prospectus supplement are underwriters of the securities offered by the prospectus supplement. 

If underwriters are used in the sale, the underwriters will acquire the securities for their own account, including through underwriting, purchase, security lending or repurchase agreements with us. The underwriters may resell the securities from time to time in one or more transactions, including negotiated transactions. Underwriters may sell the securities in order to facilitate transactions in any of our other securities (described in this prospectus or otherwise), including other public or private transactions and short sales. Underwriters may offer securities to the public either through underwriting syndicates represented by one or more managing underwriters or directly by one or more firms acting as underwriters. Unless otherwise indicated in the prospectus supplement, the obligations of the underwriters to purchase the securities will be subject to certain conditions, and the underwriters will be obligated to purchase all the offered securities if they purchase any of them. The underwriters may change from time to time any initial public offering price and any discounts or concessions allowed or reallowed or paid to dealers. 

If dealers are used in the sale of securities offered through this prospectus, we will sell the securities to them as principals. They may then resell those securities to the public at varying prices determined by the dealers at the time of resale. The prospectus supplement will include the names of the dealers and the terms of the transaction. 

Direct Sales and Sales through Agents

We may sell the securities offered through this prospectus directly. In this case, no underwriters or agents would be involved. Such securities may also be sold through agents designated from time to time. The prospectus supplement will name any agent involved in the offer or sale of the offered securities and will describe any commissions payable to the agent. Unless otherwise indicated in the prospectus supplement, any agent will agree to use its reasonable best efforts to solicit purchases for the period of its appointment. 

We may sell the securities directly to institutional investors or others who may be deemed to be underwriters within the meaning of the Securities Act with respect to any sale of those securities. The terms of any such sales will be described in the prospectus supplement. 

Delayed Delivery Contracts

If the prospectus supplement indicates, we may authorize agents, underwriters or dealers to solicit offers from certain types of institutions to purchase securities at the public offering price under delayed delivery contracts. These contracts would provide for payment and delivery on a specified date in the future. The contracts would be subject only to those conditions described in the prospectus supplement. The applicable prospectus supplement will describe the commission payable for solicitation of those contracts. 

Continuous Offering Program

Without limiting the generality of the foregoing, we may enter into a continuous offering program equity distribution agreement with a broker-dealer, under which we may offer and sell shares of our common stock from time to time through a broker-dealer as our sales agent. If we enter into such a program, sales of the shares of common stock, if any, will be made by means of ordinary brokers’ transactions on the NASDAQ Capital Market at market prices, block transactions and such other transactions as agreed upon by us and the broker-dealer. Under the terms of such a program, we also may sell shares of common stock to the broker-dealer, as principal for its own account at a price agreed upon at the time of sale. If we sell shares of common stock to such broker-dealer as principal, we will enter into a separate agreement with such broker-dealer, and we will describe this agreement in a separate prospectus supplement or pricing supplement. 

Market Making, Stabilization and Other Transactions

Unless the applicable prospectus supplement states otherwise, other than our common stock all securities we offer under this prospectus will be a new issue and will have no established trading market. We may elect to list offered securities on an exchange or in the over-the-counter market. Any underwriters that we use in the sale of offered securities may make a market in such securities, but may discontinue such market making at any time without notice. Therefore, we cannot assure you that the securities will have a liquid trading market. 

Any underwriter may also engage in stabilizing transactions, syndicate covering transactions and penalty bids in accordance with Rule 104 under the Exchange Act. Stabilizing transactions involve bids to purchase the underlying security in the open market for the purpose of pegging, fixing or maintaining the price of the securities. Syndicate covering transactions involve purchases of the securities in the open market after the distribution has been completed in order to cover syndicate short positions. 

Penalty bids permit the underwriters to reclaim a selling concession from a syndicate member when the securities originally sold by the syndicate member are purchased in a syndicate covering transaction to cover syndicate short positions. Stabilizing transactions, syndicate covering transactions and penalty bids may cause the price of the securities to be higher than it would be in the absence of the transactions. The underwriters may, if they commence these transactions, discontinue them at any time.

LEGAL MATTERS

The validity of the issuance of the securities offered by this prospectus will be passed upon for us by Lewis Roca Rothgerber Christie LLP, Las Vegas, Nevada. If certain legal matters in connection with an offering of the securities covered by this prospectus and a related prospectus supplement are passed upon by counsel for the underwriters, if any, of such offering, that counsel will be named in the related prospectus supplement for such offering.

EXPERTS

The consolidated financial statements of Riot Blockchain, Inc. and Subsidiaries as of December 31, 2019 and 2018 and for each of the two years in the period ended December 31, 2019, and Riot Blockchain, Inc.’s and Subsidiaries internal controls over financial reporting as of December 31, 2019, have been audited by Marcum LLP, independent registered public accounting firm, as stated in their reports, which are incorporated herein by reference. Marcum, LLP’s report on Riot Blockchain, Inc.’s and Subsidiaries internal controls over financial reporting as of December 31, 2019 expressed an adverse opinion because of the existence of material weaknesses identified therein. Such consolidated financial statements of Riot Blockchain, Inc. and Subsidiaries are incorporated in this prospectus by reference in reliance on the report of such firm given upon their authority as experts in accounting and auditing.

WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and special reports, along with other information with the SEC. Our SEC filings are available to the public over the Internet at the SEC’s website at http://www.sec.gov. You may also read and copy any document we file at the SEC’s Public Reference Room at 100 F Street, NE, Washington, D.C. 20549. Please call the SEC at 1-800-SEC-0330 for further information on the Public Reference Room. Our SEC filings are also available on our website, https://ir.riotblockchain.com/under the heading “Investors.” The information on this website is expressly not incorporated by reference into, and does not constitute a part of, this prospectus.

This prospectus is part of a registration statement on Form S-3 that we filed with the SEC to register the securities offered hereby under the Securities Act of 1933, as amended. This prospectus does not contain all of the information included in the registration statement, including certain exhibits and schedules. You may obtain the registration statement and exhibits to the registration statement from the SEC at the address listed above or from the SEC’s internet site.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

This prospectus is part of a registration statement filed with the SEC. The SEC allows us to “incorporate by reference” into this prospectus the information that we file with them, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be part of this prospectus, and information that we file later with the SEC will automatically update and supersede this information. The following documents are incorporated by reference and made a part of this prospectus:

We also incorporate by reference all additional documents that we file with the Securities and Exchange Commission under the terms of Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act that are made after the date of the initial registration statement but prior to effectiveness of the registration statement and after the date of this prospectus but prior to the termination of the offering of the securities covered by this prospectus. We are not, however, incorporating, in each case, any documents or information that we are deemed to furnish and not file in accordance with Securities and Exchange Commission rules.

You may request, and we will provide you with, a copy of these filings, at no cost, by calling us at (303) 794-2000 or by writing to us at the following address:

Riot Blockchain, Inc.
202 6^th Street, Suite 401
Castle Rock, CO 80104
(303) 794-2000

The information in this prospectus supplement is not complete and may be changed. We may not sell the securities pursuant to this prospectus supplement until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus supplement is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

SUBJECT TO COMPLETION, DATED October 6, 2020

$100,000,000
Common Stock

We have entered into the First Amendment (the “First Amendment”) to the At The Market Offering Agreement, dated May 24, 2019 and included as Exhibit 10.1 to our current report on Form 8-K filed with the Securities and Exchange Commission (the “Commission”) on May 24, 2019 (the “2019 Agreement”), with H.C. Wainwright & Co., LLC (our “Sales Agent” or “Wainwright”) as our sales agent for the offering of our securities covered by this prospectus supplement. The First Amendment is included as Exhibit 1.1 of the registration statement on Form S-3, of which this prospectus supplement, and the prospectus to which it relates, forms a part, filed with the Commission on October 6, 2020 (the “Registration Statement”). Effective as of the date of effectiveness of the Registration Statement, the First Amendment supplements and amends the terms of the 2019 Offering Agreement, as set forth therein, with respect to the offering of our securities covered by this prospectus supplement. In this prospectus supplement, we refer to the First Amendment and the 2019 Offering Agreement collectively as the “At The Market Offering Agreement

In accordance with the terms of the At The Market Offering Agreement, upon the effectiveness of the Registration Statement we may offer and sell shares of our common stock having an aggregate offering price of up to $100,000,000 from time to time through Wainwright acting as our sales agent. Sales of common stock, if any, under this prospectus supplement and the accompanying prospectus may be made in transactions that are deemed to be “at the market” offerings as defined in Rule 415 under the Securities Act of 1933, as amended, or the Securities Act, including sales made directly on or through the Nasdaq Capital Market, the existing trading market for our common stock, or any other existing trading market in the Unites States for our common stock, sales made to or through a market maker other than on an exchange or otherwise, directly to the sales agent as principal, in negotiated transactions at market prices prevailing at the time of sale or at prices related to such prevailing market prices, and/or in any other method permitted by law. If we and Wainwright agree on any method of distribution other than sales of shares of our common stock into the Nasdaq Capital Market or another existing trading market in the United States at market prices, we will file a further prospectus supplement providing all information about such offering as required by Rule 424(b) under the Securities Act. Wainwright will make all sales using commercially reasonable efforts consistent with its normal trading and sales practices, on mutually agreed terms between Wainwright and us. There is no arrangement for funds to be received in any escrow, trust or similar arrangement.

We will pay Wainwright a commission of up to 3% of the gross sales price of all of the shares of common stock issued by us and sold through it as our sales agent under the At The Market Offering Agreement. In connection with the sale of the common stock on our behalf, Wainwright will be deemed to be an “underwriter” within the meaning of the Securities Act and the compensation of Wainwright will be deemed to be underwriting commissions or discounts.

The securities offered by this prospectus supplement involve a significant degree of risk. Before making an investment decision, you should carefully review and consider all the information in this prospectus supplement, the accompanying base prospectus and the documents incorporated by reference herein and therein, including the risks and uncertainties described under “Risk Factors” on page S-4 of this prospectus supplement and under similar headings in the prospectus to which this prospectus supplement relates, and the other documents that are incorporated by reference into this prospectus supplement. These risks could materially affect our business, results of operations or financial condition and affect the value of our securities. You could lose all or part of your investment. Additional risks and uncertainties not presently known to us or that we currently deem immaterial may also affect our business, results of operations or financial condition. For more information, see the section entitled “Where You Can Find More Information” on page S-9 of this prospectus supplement.

Neither the 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.

H.C. Wainwright & Co.

The date of this prospectus supplement is October 6, 2020.

TABLE OF CONTENTS

Prospectus Supplement
				Page
About this prospectus supplement				S-1
Cautionary note regarding forward-looking statements				S-2
Summary				S-3
Risk factors				S-4
Use of proceeds				S-5
Dilution				S-5
Plan of Distribution				S-6
Description of Common Stock				S-8
Legal matters				S-8
Experts				S-8
Where you can find more information				S-9
Incorporation of certain information by reference				S-9

ABout this prospectus supplement

This prospectus supplement and the accompanying base prospectus to which it relates form a part of and are filed with the Registration Statement on Form S-3 (the “Registration Statement”) we filed with the Securities Exchange Commission (the “Commission” or the “SEC”) on October 6, 2020, using a “shelf” registration process to register our securities for sale for up to an aggregate offering price of $100,000,000. We may not sell any of our securities under this prospectus supplement until the Registration Statement is declared effective by the Commission. As explained more thoroughly under the section of this prospectus supplement entitled “Plan of Distribution” starting on page S-6 hereof, we intend to offer up to $100,000,000 of shares of our common stock to the public from time to time at prevailing market prices via an “at-the-market” offering conducted by our Sales Agent pursuant to the terms of the At The Market Offering Agreement, as amended.

This document consists of two parts. The first part is this prospectus supplement, which describes the specific terms of this offering. The second part, the accompanying prospectus, gives more general information, some of which may not apply to this offering. Generally, when we refer only to the “prospectus,” we are referring to both parts combined. This prospectus supplement may add to, update or change information in the accompanying prospectus and the documents incorporated by reference into this prospectus supplement or the accompanying prospectus. To the extent there is a conflict between the information contained in this prospectus supplement and the information contained in the accompanying prospectus or any document incorporated by reference therein filed prior to the date of this prospectus supplement, you should rely on the information in this prospectus supplement; provided that if any statement in one of these documents is inconsistent with a statement in another document having a later date — for example, a document incorporated by reference in the accompanying prospectus — the statement in the document having the later date modifies or supersedes the earlier statement.

We further note that the representations, warranties and covenants made by us in any agreement that is filed as an exhibit to any document that is incorporated by reference herein were made solely for the benefit of the parties to such agreement, including, in some cases, for the purpose of allocating risk among the parties to such agreements, and should not be deemed to be a representation, warranty or covenant to you. Moreover, such representations, warranties or covenants were accurate only as of the date when made. Accordingly, such representations, warranties and covenants should not be relied on as accurately representing the current state of our affairs.

Neither we nor the Sales Agent have authorized anyone to provide information different from that contained in this prospectus supplement and the accompanying prospectus, including any free writing prospectus that we have authorized for use in this offering. When you make a decision about whether to invest in our common stock, you should not rely upon any information other than the information in this prospectus supplement or the accompanying prospectus, including any free writing prospectus that we have authorized for use in this offering. Neither the delivery of this prospectus supplement or the accompanying prospectus, including any free writing prospectus that we have authorized for use in this offering, nor the sale of our common stock means that information contained in this prospectus supplement and the accompanying prospectus, including any free writing prospectus that we have authorized for use in this offering, is correct after their respective dates. It is important for you to read and consider all information contained in this prospectus supplement and the accompanying prospectus, including the information incorporated by reference into this prospectus supplement and the accompanying prospectus, and any free writing prospectus that we have authorized for use in connection with this offering in making your investment decision. You should also read and consider the information in the documents to which we have referred you in the sections entitled “Where You Can Find More Information” and “Incorporation of Certain Information by Reference” in this prospectus supplement.

We are offering to sell, and seeking offers to buy, shares of our common stock only in jurisdictions where offers and sales are permitted. The distribution of this prospectus supplement and the accompanying prospectus and the offering of the common stock in certain jurisdictions may be restricted by law. Persons outside the United States who come into possession of this prospectus supplement and the accompanying prospectus must inform themselves about, and observe any restrictions relating to, the offering of the common stock and the distribution of this prospectus supplement and the accompanying prospectus outside the United States. This prospectus supplement and the accompanying prospectus do not constitute, and may not be used in connection with, an offer to sell, or a solicitation of an offer to buy, any securities offered by this prospectus supplement and the accompanying prospectus by any person in any jurisdiction in which it is unlawful for such person to make such an offer or solicitation.

Unless otherwise stated, all references in this prospectus to “we,” “us,” “our,” “Riot,” the “Company” and similar designations refer to Riot Blockchain, Inc., a Nevada corporation, and its affiliated subsidiaries.

CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus supplement and the base prospectus to which it relates, including the documents that we incorporate by reference into both, contains 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”). Such forward-looking statements include those that express plans, anticipation, intent, contingency, goals, targets or future development and/or otherwise are not statements of historical fact. We believe these forward-looking statements are reasonable; however, you should not place undue reliance on any forward-looking statements, which are based on current expectations. These forward-looking statements are based on our current expectations and projections about future events and they are subject to risks and uncertainties known and unknown that could cause actual results and developments to differ materially from those expressed or implied in such statements.

 In some cases, you can identify forward-looking statements by terminology, such as “expects,” “anticipates,” “intends,” “estimates,” “plans,” “believes,” “seeks,” “may,” “should,” “could” or the negative of such terms or other similar expressions. Accordingly, these statements involve estimates, assumptions and uncertainties that could cause actual results to differ materially from those expressed in them. Any forward-looking statements are qualified in their entirety by reference to the factors discussed throughout this prospectus supplement. We intend for these forward-looking statements to be covered by the safe harbor provisions for forward-looking statements contained in the Private Securities Litigation Reform Act of 1995, and we are including this statement for purposes of complying with these safe harbor provisions.

 You should read this prospectus supplement and the documents that we reference herein and therein and have filed as exhibits to the registration statement, of which this prospectus supplement, the prospectus to which it relates, and any subsequent prospectus supplement is part, completely and with the understanding that our actual future results may be materially different from what we expect. You should assume that the information appearing in this prospectus supplement is accurate as of the date on the front cover of this prospectus supplement or such prospectus supplement only. Because the risk factors referred to above, as well as the risk factors incorporated herein by reference, could cause actual results or outcomes to differ materially from those expressed in any forward-looking statements made by us or on our behalf, you should not place undue reliance on any forward-looking statements. Further, any forward-looking statement speaks only as of the date on which it is made, and we undertake no obligation to update any forward-looking statement to reflect events or circumstances after the date on which the statement is made or to reflect the occurrence of unanticipated events, except as may be required under applicable law. New factors emerge from time to time, and it is not possible for us to predict which factors will arise. In addition, we cannot assess the impact of each factor on our business or the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in any forward-looking statements. We qualify all of the information presented in this prospectus supplement and particularly our forward-looking statements, by these cautionary statements.

SUMMARY

This summary highlights selected information from this prospectus supplement and does not contain all of the information that you should consider in making your investment decision. You should carefully read this entire prospectus supplement, the prospectus to which it relates, and any applicable subsequent prospectus supplements or related free writing prospectuses. Before making an investment decision, you should carefully review and consider the risks and uncertainties associated with investing in our securities we have identified, which are discussed under the heading “Risk Factors” on page S-4 of this prospectus supplement, as well as those risk factors discussed under the heading “Risk Factors” in the prospectus to which this relates, and those discussed under similar headings contained in any applicable prospectus supplement, any related free writing prospectus, and under similar headings in the documents that are incorporated by reference into this prospectus supplement. You should also carefully read the information incorporated by reference into this prospectus supplement, including our financial statements, and the exhibits to the registration statement of which this prospectus supplement is a component. For more information, see the section entitled “Where You Can Find More Information” on page S-8 of this prospectus supplement.

The Offering

⁽¹⁾ The number of shares of our common stock to be outstanding immediately after this offering as shown above is based upon 48,922,780 shares outstanding as of October 2, 2020, and, unless otherwise indicated does not include: (i) 1,708,144 shares issuable upon the exercise of vested and exercisable warrants to acquire shares at an exercise price of $1.94 per share issued in January 2019 to investors in the private placement transaction we reported on our current report on Form 8-K, filed on February 2, 2019 (the “January 2019 Warrants”); (ii) 1,646,113 shares issuable upon the exercise of vested and exercisable warrants to purchase shares of our common stock at an exercise price of $40.00 per share, which were issued to investors in the December 21, 2017 private placement we reported in our current report on Form 8-K, filed on December 21, 2017 (the “December 2017 Warrants”); (iii) 1,416,816 shares issuable upon settlement of 1,416,816 restricted stock units (“RSUs”) granted under the Company’s 2019 Equity Incentive Plan (the “2019 Plan”), of which 103,361 are vested and 1,313,455 remain unvested subject to regular vesting schedules; and (iv) 561,809 shares of common stock reserved for future issuance under our 2019 Plan.

Risk factors

Investing in our securities involves a high degree of risk. Before making an investment decision, you should consider carefully the risks, uncertainties and all risk factors set forth in the applicable prospectus supplement and the documents incorporated by reference in this prospectus supplement, including the risk factors discussed under the heading “Risk Factors” in the prospectus to which this prospectus supplement forms a part, as well as those disclosed under the same heading in our most recent Annual Report on Form 10-K for the year ended December 31, 2019, as amended, and each subsequently filed quarterly report on Form 10-Q and current reports on Form 8-K, which may be amended, supplemented or superseded from time to time by the other reports we file with the SEC in the future.

In addition to those risk factors incorporated by reference herein, the Company has identified the following uncertainties and risk factors which may affect our business:

Risks Relating to this Offering

Future sales or other issuances of our common stock could depress the market for our common stock.

Sales of a substantial number of shares of our common stock, or the perception by the market that those sales could occur, whether through this offering or other offerings of our securities, could cause the market price of our common stock to decline or could make it more difficult for us to raise funds through the sale of equity in the future.

The issuance and sale of a significant number of our securities will cause our current stockholders’ holdings to be significantly diluted. In addition, our current stockholders’ holdings may also be diluted if we enter into arrangements with third parties permitting us to issue shares of common stock in lieu of certain cash payments upon the achievement of milestones.

We have broad discretion to use the net proceeds from this offering and our investment of these proceeds pending any such use may not yield a favorable return.

Our management has broad discretion as to how to spend the proceeds from this offering and may spend these proceeds in ways with which our stockholders may not agree. We may use a substantial portion of the proceeds we receive from the sales of our Common Stock made pursuant to this prospectus supplement by our Sales Agent to purchase new application-specific integrated circuit (ASIC) chip cryptocurrency mining computers (“miners”), which are subject to significant fluctuations in market price. Management cannot guarantee that its decisions regarding its use of the proceeds from the sales of our common stock under this prospectus supplement will produce gainful returns or will result in any appreciation in the value of the Company.

This offering is being conducted on a “commercially reasonable efforts” basis; we cannot guarantee our success in raising additional capital in this offering.

The Sales Agent will be attempting to sell the shares of our common stock offered under this prospectus supplement on a “commercially reasonable efforts” basis, and the Sales Agent is under no obligation to purchase any shares of our common stock offered under this prospectus supplement for their own account. Neither we nor the Sales Agent is required to sell any specific number or dollar amount of shares of common stock in this offering but will use its commercially reasonable efforts to sell the shares of our common stock offered in this prospectus supplement at management’s direction. As a “commercially reasonable efforts” offering, there can be no assurance that the offering contemplated hereby will ultimately be consummated and, accordingly, we may not raise any additional capital.

If we are unable to raise additional capital through the offering contemplated in this prospectus supplement, we may not be able to continue to fund our operations and we may have to reduce or even halt our operations entirely. Our failure to raise additional capital through the offering contemplated in this prospectus supplement may cause us to cease as a going concern and investors in our securities may lose their entire investment.

Purchasers in this offering will experience immediate and substantial dilution in the book value of their investment.

The public offering price of our common stock is substantially higher than the net tangible book value per share of our common stock as of June 30, 2020, before giving effect to this offering. At an assumed public offering price of $2.60 per share (which was the last reported sales price per share of our stock on October 2, 2020), we will have 87,384,328 shares of Common Stock issued and outstanding after completion of this offering. After deducting estimated offering expenses and estimated sales agent commissions payable by us, our pro forma, as adjusted, net tangible book value per share after giving effect to the sale of shares of our Common Stock in the aggregate amount of $100,000,000 at the assumed offering price would be $1.74 Accordingly, purchasers of shares of our Common Stock in this offering will incur immediate and substantial dilution of approximately $0.86 per share, representing the difference between the pro forma net tangible book value per share of our securities after the offering and the pro forma net tangible book value per share of our securities prior to the offering. If the price at which the shares of our common stock are sold in this offering increases, the dilution experienced by such purchasers will increase proportionately. Furthermore, if previously issued and outstanding options or warrants are exercised, or if additional derivative securities are issued, you could experience further dilution upon their conversion into shares of our Common Stock. For a further description of the dilution that our stockholders will experience immediately after this offering, see the section in this prospectus supplement entitled “Dilution” on page S-5 of this prospectus supplement.

The common stock offered hereby will be sold in "at-the-market" offerings, and investors who buy shares at different times will likely pay different prices.

Investors who purchase shares in this offering at different times will likely pay different prices, and so may experience different outcomes in their investment results. We will have discretion, subject to market demand, to vary the timing, prices and numbers of shares sold, and there is no minimum or maximum sales price. Investors may experience a decline in the value of their shares as a result of share sales made at prices lower than the prices they paid.

The actual number of shares we will issue under the sales agreement, at any one time or in total, is uncertain.

Subject to certain limitations in the At The Market Offering Agreement and in compliance with applicable law, we have the discretion to deliver a sales notice to Wainwright at any time throughout the term of the At The Market Offering Agreement. The number of shares that are sold by Wainwright after we deliver a sales notice will fluctuate based on the market price of the common stock during the sales period and limits we set with Wainwright. Because the price per share of each share sold will fluctuate based on the market price of our common stock during the sales period, it is not possible at this stage to predict the number of shares that will be ultimately issued.

USE OF PROCEEDS

Unless otherwise indicated in a subsequent prospectus supplement, we intend to use the net proceeds from the sale of shares of our common stock by the Sales Agent under this prospectus supplement for general corporate purposes, which may include capital expenditures, funding potential acquisitions of additional new mining equipment, other potential acquisitions, and general working capital. We will have significant discretion in the use of any net proceeds. Investors will be relying on the judgment of our management regarding the application of the proceeds of any sale of securities. We may invest the net proceeds temporarily until we use them for their stated purpose, as applicable.

The expected use of the net proceeds from the sale of common stock offered by this prospectus supplement represents our intentions based upon our current plans. The amounts and timing of our actual expenditures of such proceeds may vary significantly depending on numerous factors and, as a result, our management will retain broad discretion over the allocation of the net proceeds from this offering. 

Dividend policy

We did not declare or pay any cash dividends on our common stock in 2019 or in 2020, and, as of the date of this prospectus supplement, and we do not anticipate paying any cash dividends in the foreseeable future. Any future determination to pay dividends will be at the discretion of our board of directors.

Dilution

If you invest in our common stock, your ownership interest will be immediately diluted to the extent of the difference between the offering price per share of our common stock and the as adjusted net tangible book value per share of our common stock after this offering.

As of June 30, 2020, our net tangible book value was approximately $20,151,000, or $0.55 per share of common stock. Such net tangible book value per share represents the amount of our total tangible assets, less total liabilities, divided by the total number of shares of our common stock issued and outstanding as of June 30, 2020, which was 36,559,279 shares.

After giving effect to the 12,363,511 shares of our common stock and related net proceeds issued subsequent to June 30, 2020 through October 2, 2020, our pro forma net tangible book value as of June 30, 2020 would have been $54,260,226, or $1.11 per share, based on 48,922,780 shares issued and outstanding. These 12,363,511 shares of our common stock and related net proceeds were issued as follows: (i) 12,028,964 shares issued under our registration statement on Form S-3 (Registration Number 333-226111) to purchasers of shares of our common stock in a public offering pursuant to the terms of the 2019 Offering Agreement with our Sales Agent, Wainwright; (ii) 200,000 shares issued to a holder of the January 2019 Warrants upon the holder’s exercise of its right to purchase 200,000 shares; and (iii) 134,547 net shares issued in settlement of vested RSUs, net of tax, issued under our 2019 Plan.

After giving further effect to the sale of shares of our common stock in the aggregate amount of $100,000,000 in this offering at an assumed public offering price of $2.60 per share (which was the last reported sale price of shares of our common stock on October 2, 2020) and after deducting estimated offering expenses and after deducting estimated sales agent commissions payable by us, our pro forma net tangible book value as of June 30, 2020, as adjusted, would have been approximately $151,682,247 or $1.74 per share of common stock, based on 87,384,328 shares issued and outstanding (assuming all $100,000,000 of shares are sold at the assumed offering price of $2.60 per share). This would represent an immediate change in pro forma net tangible book value, as adjusted, of $0.63 per share to existing stockholders and of $(0.86) per share to new investors purchasing shares of common stock in this offering. The following table illustrates this dilution:

This table assumes, for illustrative purposes only, the sale of shares of our common stock in the aggregate amount of $100,000,000 at the assumed offering price of $2.60 per share, which was the last reported sale price of shares of our common stock on October 2, 2020.

This offering is being made pursuant to Rule 415(a) of the Securities Act and the actual sales price of shares of our common stock will vary from time to time based on prevailing market prices. Accordingly, the actual dilution experienced by purchasers of our common stock, as well as the total number of shares sold, may increase or decrease with the actual price per share of our common stock sold in this offering. For example, a decrease in the price at which the shares are actually sold in this offering of $1.00 per share from the assumed offering price of $2.60 per share shown in the table above (assuming all of our common stock in the aggregate amount of $100,000,000 is sold at that reduced price) would result in an adjusted pro forma net tangible book value per share after the offering of $1.36 and result in an immediate dilution in the adjusted pro forma net tangible book value of $0.24 per share to new purchasers of our common stock in this offering. Conversely, assuming all of our common stock in the aggregate amount of $100,000,000 is sold, an increase in the price at which the shares are actually sold in this offering of $1.00 per share from the assumed offering price of $2.60 per share would result in an adjusted pro forma net tangible book value after the offering of $1.98 per share and an immediate dilution in adjusted pro forma net tangible book value of $1.62 per share to purchasers of our common stock in this offering.

The above computation is based on 48,922,780 shares of our common stock issued and outstanding at October 2, 2020 and does not include the following:

• 1,708,144 shares issuable to holders of the vested and exercisable January 2019 Warrants upon the exercise of their right to acquire shares;
• 1,646,113 shares issuable to holders of vested and exercisable December 2017 Warrants;
• 1,416,816 shares issuable upon settlement of 1,416,816 RSUs granted under our 2019 Plan, of which 103,361 are vested and 1,313,455 remain unvested subject to regular vesting schedules; and
• 561,809 shares of common stock reserved for future issuance under our 2019 Plan.

To the extent we issue, subsequent to the date of this prospectus supplement, shares in connection with the exercise of these warrants, in settlement of these RSUs, or if we otherwise issue additional shares, there will be further dilution to investors participating in this offering.

PLAN OF DISTRIBUTION

We have entered into an At The Market Offering Agreement, dated as of May 24, 2019 and as amended on October 6, 2020, with Wainwright under which we may issue and sell up to $100,000,000 of shares of our common stock from time to time under this Registration Statement through Wainwright as our sales agent pursuant to this prospectus supplement. The At The Market Offering Agreement provides that sales of our common stock, if any, under this prospectus supplement may be made in sales deemed to be “at-the-market” equity offerings as defined in Rule 415(a)(4) promulgated under the Securities Act. If we and Wainwright agree on any method of distribution other than sales of shares of our common stock into the Nasdaq Capital Market or another existing trading market in the United States at market prices, we will file a further prospectus supplement providing all information about such offering as required by Rule 424(b) under the Securities Act.

From time to time during the term of the At The Market Offering Agreement, we may deliver a sales notice to the Sales Agent specifying the length of the selling period, the amount of common stock to be sold and the minimum price below which sales may not be made. Upon receipt of a sales notice from us, and subject to the terms and conditions of the At The Market Offering Agreement, the Sales Agent agrees to use its commercially reasonable efforts consistent with its normal trading and sales practices and applicable law and regulations to sell such shares of our common stock on such terms. We or the Sales Agent may suspend the offering of our common stock at any time upon proper notice to the other, at which time the sales notice will immediately terminate. Settlement for sales of our common stock will occur at 10:00 a.m. (New York City time), or at some other time that is agreed upon by us and Wainwright in connection with a particular transaction, on the second trading day following the date any sales were made, unless we otherwise agree with the Sales Agent. The obligation of the Sales Agent under the At The Market Offering Agreement to sell shares of our common stock pursuant to any sales notice is subject to a number of conditions, which the Sales Agent may waive in its sole discretion. Sales of our common stock as contemplated in this prospectus supplement will be settled through the facilities of The Depository Trust Company or by such other means as we and Wainwright may agree upon. There is no arrangement for funds to be received in an escrow, trust or similar arrangement.

We will pay the Sales Agent a placement fee of up to 3% of the gross sales price of the shares of our common stock that the Sales Agent sells pursuant to the At The Market Offering Agreement. Because there is no minimum offering amount required as a condition to close this offering, the actual total public offering amount, commissions and proceeds to us, if any, are not determinable at this time. Pursuant to the At The Market Offering Agreement, we have also agreed to reimburse Wainwright for certain specified expenses, including the fees and disbursements of its legal counsel in an amount not to exceed $50,000 and for the fees and disbursements of its legal counsel in connection with Wainwright’s ongoing diligence, drafting and other filing requirements arising from this offering in an amount not to exceed $2,500 in the aggregate per calendar quarter. We estimate that the total expenses for the offering, excluding compensation and reimbursements payable to Wainwright under the terms of the At The Market Offering Agreement, will be approximately $60,000.

To the extent required by Regulation M, Wainwright will not engage in any market making activities involving our shares of common stock while the offering is ongoing under this prospectus supplement. Wainwright and its affiliates may in the future provide various investment banking and other financial services for us and our affiliates, for which services they may in the future receive customary fees.

In connection with the sale of the common stock on our behalf, Wainwright will be deemed to be an “underwriter” within the meaning of the Securities Act and the compensation of Wainwright will be deemed to be underwriting commissions or discounts. We have agreed to provide indemnification and contribution to Wainwright against certain civil liabilities, including liabilities under the Securities Act.

We will report at least quarterly the number of shares of our common stock sold through the Sales Agent, as our agent, in this offering and, to the extent applicable, the number of shares of our common stock issued upon settlement of any terms agreements, and the net proceeds to us in connection with such sales of our common stock.

The offering of our common stock pursuant to the At The Market Offering Agreement will terminate upon the earlier of: (1) the sale of all of our common stock subject to the At The Market Offering Agreement; (2) termination of the At The Market Offering Agreement by either us or the Sales Agent at any time upon five (5) business days’ notice in the respective party’s sole discretion; (3) the expiration of the Registration Statement of which this prospectus supplement and the accompanying prospectus forms a part; or (4) by the mutual agreement of the parties to the At The Market Offering Agreement.

The foregoing description of the At The Market Offering Agreement is qualified in its entirety by the 2019 Offering Agreement, as amended by the First Amendment. The 2019 Offering Agreement between the Company and Wainwright, dated as of May 24, 2019, is included as Exhibit 1.01 to the Company’s current report on Form 8-K filed with the Commission on May 24, 2019. The First Amendment to the 2019 Offering Agreement between the Company and Wainwright, dated as of the date of effectiveness of the Registration Statement on Form S-3 of which this prospectus supplement and the associated prospectus form a part, is included as Exhibit 1.1 to the Registration Statement, as filed with the Commission on October 6, 2020. 

DESCRIPTION OF COMMON STOCK

General

We are authorized to issue 170,000,000 shares of common stock, at no par value per share.

Holders of the Company’s common stock are entitled to one vote for each share on all matters submitted to a stockholder vote. Holders of common stock do not have cumulative voting rights. Therefore, holders of a majority of the shares of common stock voting for the election of directors can elect all of the directors. Holders of the Company’s common stock representing a third of the voting power of the Company’s capital stock issued, outstanding and entitled to vote, represented in person or by proxy, are necessary to constitute a quorum at any meeting of stockholders. A vote by the holders of a majority of the Company’s outstanding shares is required to effectuate certain fundamental corporate changes such as liquidation, merger or an amendment to the Company’s certificate of incorporation.

Holders of the Company’s common stock are entitled to share in all dividends that the board of directors, in its discretion, declares from legally available funds. In the event of a liquidation, dissolution or winding up, each outstanding share entitles its holder to participate pro rata in all assets that remain after payment of liabilities and after providing for each class of stock, if any, having preference over the common stock. The Company’s common stock has no pre-emptive rights, no conversion rights and there are no redemption provisions applicable to the Company’s common stock.

Classified Board of Directors

Our Bylaws provide for our Board to be divided into three classes, with each class serving a staggered three-year term. We believe that a classified board structure, if implemented, would help to ensure the continuity and stability of the Board and our business strategies and policies. The classified board structure could have the effect of making the removal of incumbent directors more time consuming and difficult, and, therefore may discourage a third party from making a tender offer or otherwise attempting to obtain control of us, even though such an attempt might be beneficial to us and our stockholders.

Transfer Agent and Registrar

The transfer agent and registrar for our common stock is Corporate Stock Transfer, Inc., Denver, Colorado.

Equiniti Trust Company, d/b/a “EQ by Equiniti,” Mendota Heights, Michigan.

Listing

Our common stock is currently traded on the NASDAQ Capital Market under the symbol “RIOT.”“RIOT”.

DESCRIPTION OF PREFERRED STOCK

General

The Company’s articles of incorporation authorize the issuance of 15,000,000 shares of “blank check” preferred stock, no par value per share, in one or more series, subject to any limitations prescribed by law, without further vote or action by the stockholders. Each such series of preferred stock shall have such number of shares, designations, preferences, voting powers, qualifications, and special or relative rights or privileges as shall be determined by our board of directors, which may include, among others, dividend rights, voting rights, liquidation preferences, conversion rights and preemptive rights. 

Preferred stock is available for possible future financings or acquisitions and for general corporate purposes without further authorization of stockholders unless such authorization is required by applicable law, the rules of the NASDAQ Capital Market or other securities exchange or market on which our stock is then listed or admitted to trading.

Our board of directors may authorize the issuance of preferred stock with voting or conversion rights that could adversely affect the voting power or other rights of the holders of common stock. The issuance of preferred stock, while providing flexibility in connection with possible acquisitions and other corporate purposes could, under some circumstances, have the effect of delaying, deferring or preventing a change in control of the Company.

A prospectus supplement relating to any series of preferred stock being offered will include specific terms relating to the offering. Such prospectus supplement will include:

·

the title and stated or par value of the preferred stock;

·

the number of shares of the preferred stock offered, the liquidation preference per share and the offering price of the preferred stock;

·

the dividend rate(s), period(s) and/or payment date(s) or method(s) of calculation thereof applicable to the preferred stock;

·

whether dividends shall be cumulative or non-cumulative and, if cumulative, the date from which dividends on the preferred stock shall accumulate;

·

the provisions for a sinking fund, if any, for the preferred stock;

·

any voting rights of the preferred stock;

·

the provisions for redemption, if applicable, of the preferred stock;

·

any listing of the preferred stock on any securities exchange;

·

the terms and conditions, if applicable, upon which the preferred stock will be convertible into our common stock, including the conversion price or the manner of calculating the conversion price and conversion period;

·

if appropriate, a discussion of Federal income tax consequences applicable to the preferred stock;

·

and any other specific terms, preferences, rights, limitations or restrictions of the preferred stock.

The terms, if any, on which the preferred stock may be convertible into or exchangeable for our common stock will also be stated in the preferred stock prospectus supplement. The terms will include provisions as to whether conversion or exchange is mandatory, at the option of the holder or at our option, and may include provisions pursuant to which the number of shares of our common stock to be received by the holders of preferred stock would be subject to adjustment.

Series B Preferred Stock

DESCRIPTION OF WARRANTS

We may issue warrants for the purchase of preferred stock or common stock. Warrants may be issued independently or together with any preferred stock or common stock, and may be attached to or separate from any offered securities. Each series of warrants will be issued under a separate warrant agreement to be entered into between a warrant agent specified in the agreement and us. The warrant agent will act solely as our agent in connection with the warrants of that series and will not assume any obligation or relationship of agency or trust for or with any holders or beneficial owners of warrants. This summary of some provisions of the securities warrants is not complete. You should refer to the securities warrant agreement, including the forms of securities warrant certificate representing the securities warrants, relating to the specific securities warrants being offered for the complete terms of the securities warrant agreement and the securities warrants. The securities warrant agreement, together with the terms of the securities warrant certificate and securities warrants, will be filed with the Securities and Exchange Commission in connection with the offering of the specific warrants.

The applicable prospectus supplement will describe the following terms, where applicable, of the warrants in respect of which this prospectus is being delivered:

·

the title of the warrants;

·

the aggregate number of the warrants;

·

the price or prices at which the warrants will be issued;

·

the designation, amount and terms of the offered securities purchasable upon exercise of the warrants;

·

if applicable, the date on and after which the warrants and the offered securities purchasable upon exercise of the warrants will be separately transferable;

·

the terms of the securities purchasable upon exercise of such warrants and the procedures and conditions relating to the exercise of such warrants;

·

any provisions for adjustment of the number or amount of securities receivable upon exercise of the warrants or the exercise price of the warrants;

·

the price or prices at which and currency or currencies in which the offered securities purchasable upon exercise of the warrants may be purchased;

·

the date on which the right to exercise the warrants shall commence and the date on which the right shall expire;

·

the minimum or maximum amount of the warrants that may be exercised at any one time;

·

information with respect to book-entry procedures, if any;

·

if appropriate, a discussion of Federal income tax consequences; and

·

any other material terms of the warrants, including terms, procedures and limitations relating to the exchange and exercise of the warrants.

Warrants for the purchase of common stock or preferred stock will be offered and exercisable for U.S. dollars only. Warrants will be issued in registered form only.

Upon receipt of payment and the warrant certificate properly completed and duly executed at the corporate trust office of the warrant agent or any other office indicated in the applicable prospectus supplement, we will, as soon as practicable, forward the purchased securities. If less than all of the warrants represented by the warrant certificate are exercised, a new warrant certificate will be issued for the remaining warrants.

Prior to the exercise of any securities warrants to purchase preferred stock or common stock, holders of the warrants will not have any of the rights of holders of the common stock or preferred stock purchasable upon exercise, including in the case of securities warrants for the purchase of common stock or preferred stock, the right to vote or to receive any payments of dividends on the preferred stock or common stock purchasable upon exercise.

DESCRIPTION OF UNITS

As specified in the applicable prospectus supplement, we may issue units consisting of shares of common stock, shares of preferred stock or warrants or any combination of such securities.

The applicable prospectus supplement will specify the following terms of any units in respect of which this prospectus is being delivered:

·

the terms of the units and of any of the common stock, preferred stock and warrants comprising the units, including whether and under what circumstances the securities comprising the units may be traded separately;

·

a description of the terms of any unit agreement governing the units; and

·

a description of the provisions for the payment, settlement, transfer or exchange of the units.

PLAN OF DISTRIBUTION

·

the terms of the offering;

·

the names of any underwriters or agents;

·

the name or names of any managing underwriter or underwriters;

·

the purchase price of the securities;

·

any over-allotment options under which underwriters may purchase additional securities from us;

·

the net proceeds from the sale of the securities;

·

any delayed delivery arrangements;

·

any underwriting discounts, commissions and other items constituting underwriters’ compensation;

·

any initial public offering price;

·

any discounts or concessions allowed or reallowed or paid to dealers;

·

any commissions paid to agents; and

·

any securities exchange or market on which the securities may be listed.

Only underwriters named in the prospectus supplement are underwriters of the securities offered by the prospectus supplement.

If underwriters are used in the sale, the underwriters will acquire the securities for their own account, including through underwriting, purchase, security lending or repurchase agreements with us. The underwriters may resell the securities from time to time in one or more transactions, including negotiated transactions. Underwriters may sell the securities in order to facilitate transactions in any of our other securities (described in this prospectus or otherwise), including other public or private transactions and short sales. Underwriters may offer securities to the public either through underwriting syndicates represented by one or more managing underwriters or directly by one or more firms acting as underwriters. Unless otherwise indicated in the prospectus supplement, the obligations of the underwriters to purchase the securities will be subject to certain conditions, and the underwriters will be obligated to purchase all the offered securities if they purchase any of them. The underwriters may change from time to time any initial public offering price and any discounts or concessions allowed or reallowed or paid to dealers.

If dealers are used in the sale of securities offered through this prospectus, we will sell the securities to them as principals. They may then resell those securities to the public at varying prices determined by the dealers at the time of resale. The prospectus supplement will include the names of the dealers and the terms of the transaction.

We may sell the securities offered through this prospectus directly. In this case, no underwriters or agents would be involved. Such securities may also be sold through agents designated from time to time. The prospectus supplement will name any agent involved in the offer or sale of the offered securities and will describe any commissions payable to the agent. Unless otherwise indicated in the prospectus supplement, any agent will agree to use its reasonable best efforts to solicit purchases for the period of its appointment.

We may sell the securities directly to institutional investors or others who may be deemed to be underwriters within the meaning of the Securities Act with respect to any sale of those securities. The terms of any such sales will be described in the prospectus supplement.

Delayed Delivery Contracts

If the prospectus supplement indicates, we may authorize agents, underwriters or dealers to solicit offers from certain types of institutions to purchase securities at the public offering price under delayed delivery contracts. These contracts would provide for payment and delivery on a specified date in the future. The contracts would be subject only to those conditions described in the prospectus supplement. The applicable prospectus supplement will describe the commission payable for solicitation of those contracts.

Continuous Offering Program

Without limiting the generality of the foregoing, we may enter into a continuous offering program equity distribution agreement with a broker-dealer, under which we may offer and sell shares of our common stock from time to time through a broker-dealer as our sales agent. If we enter into such a program, sales of the shares of common stock, if any, will be made by means of ordinary brokers’ transactions on the NASDAQ Capital Market at market prices, block transactions and such other transactions as agreed upon by us and the broker-dealer. Under the terms of such a program, we also may sell shares of common stock to the broker-dealer, as principal for its own account at a price agreed upon at the time of sale. If we sell shares of common stock to such broker-dealer as principal, we will enter into a separate agreement with such broker-dealer, and we will describe this agreement in a separate prospectus supplement or pricing supplement.

Market Making, Stabilization and Other Transactions

Unless the applicable prospectus supplement states otherwise, other than our common stock all securities we offer under this prospectus will be a new issue and will have no established trading market. We may elect to list offered securities on an exchange or in the over-the-counter market. Any underwriters that we use in the sale of offered securities may make a market in such securities, but may discontinue such market making at any time without notice. Therefore, we cannot assure you that the securities will have a liquid trading market.

Any underwriter may also engage in stabilizing transactions, syndicate covering transactions and penalty bids in accordance with Rule 104 under the Exchange Act. Stabilizing transactions involve bids to purchase the underlying security in the open market for the purpose of pegging, fixing or maintaining the price of the securities. Syndicate covering transactions involve purchases of the securities in the open market after the distribution has been completed in order to cover syndicate short positions.

Penalty bids permit the underwriters to reclaim a selling concession from a syndicate member when the securities originally sold by the syndicate member are purchased in a syndicate covering transaction to cover syndicate short positions. Stabilizing transactions, syndicate covering transactions and penalty bids may cause the price of the securities to be higher than it would be in the absence of the transactions. The underwriters may, if they commence these transactions, discontinue them at any time.

LEGAL MATTERS

EXPERTS

EXPERTS

The consolidated balance sheetfinancial statements of Riot Blockchain, Inc. (formerly: Bioptix, Inc.)and Subsidiaries as of December 31, 2017,2019 and 2018 and for each of the related consolidated statementstwo years in the period ended December 31, 2019, and Riot Blockchain, Inc.’s and Subsidiaries internal controls over financial reporting as of operations, stockholders' equity, and cash flows for the year then endedDecember 31, 2019, have been audited by MNP LLP, as stated in their report, which is incorporated herein by reference. Such consolidated financial statements are incorporated herein by reference in reliance upon such report given on the authority of such firm as experts in accounting and auditing.

The consolidated balance sheet of Riot Blockchain, Inc. (formerly: Bioptix, Inc.) as of December 31, 2016, and the related consolidated statements of operations, stockholders’ equity, and cash flows for the year then ended, have been audited by EisnerAmperMarcum LLP, independent registered public accounting firm, as stated in their reportreports, which isare incorporated herein by reference. Marcum, LLP’s report on Riot Blockchain, Inc.’s and Subsidiaries internal controls over financial reporting as of December 31, 2019 expressed an adverse opinion because of the existence of material weaknesses identified therein. Such consolidated financial statements have beenof Riot Blockchain, Inc. and Subsidiaries are incorporated hereinin this prospectus supplement by reference in reliance on the report of such firm given upon their authority as experts in accounting and auditing.

WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and special reports, along with other information with the SEC. Our SEC filings are available to the public over the Internet at the SEC’s website at http://www.sec.gov. You may also read and copy any document we file at the SEC’s Public Reference Room at 100 F Street, NE, Washington, D.C. 20549. Please call the SEC at 1-800-SEC-0330 for further information on the Public Reference Room. Our SEC filings are also available on our website, https://ir.riotblockchain.com/under the heading “Investors.” The information on this website is expressly not incorporated by reference into, and does not constitute a part of, this prospectus.prospectus supplement.

This prospectus supplement is part of a registration statement on Form S-3 that we filed with the SEC to register the securities offered hereby under the Securities Act of 1933, as amended. This prospectus supplement does not contain all of the information included in the registration statement, including certain exhibits and schedules. You may obtain the registration statement and exhibits to the registration statement from the SEC at the address listed above or from the SEC’s internet site.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

This prospectus supplement is part of a registration statement on Form S-3 filed with the SEC. The SEC allows us to “incorporate by reference” into this prospectus supplement the information that we file with them, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be part of this prospectus supplement, and information that we file later with the SEC will automatically update and supersede this information. The following documents are incorporated by reference and made a part of this prospectus:prospectus supplement:

We also incorporate by reference all additional documents that we file with the Securities and Exchange Commission under the terms of Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act that are made after the date of the initial registration statement but prior to effectiveness of the registration statement and after the date of this prospectus supplement but prior to the termination of the offering of the securities covered by this prospectus.prospectus supplement. We are not, however, incorporating, in each case, any documents or information that we are deemed to furnish and not file in accordance with Securities and Exchange Commission rules.

You may request, and we will provide you with, a copy of these filings, at no cost, by calling us at (303) 794-2000 or by writing to us at the following address:

Riot Blockchain, Inc.

202 6^th6th Street, Suite 401
Castle Rock, CO 80104

(303) 794-2000

Riot Blockchain, Inc.

$100,000,000

$100,000,000

Common Stock

Preferred Stock

Warrants

Units

RIOT BLOCKCHAIN, INC.

Prospectus

 , 2019

Prospectus Supplement

H.C. Wainwright & Co.

_____________, 2020