[S-3] Aqua Metals, Inc. Shelf Registration Statement

Rhea-AI Filing Summary

Aqua Metals, Inc. filed a resale registration covering up to 1,133,794 shares of common stock issuable upon exercise of common stock purchase warrants held by a single selling stockholder. The warrants were issued on October 16, 2025, carry a $11.34 per‑share exercise price, may be exercised on a cashless basis in certain circumstances, and expire on October 16, 2030. The company will not receive proceeds from any resale by the holder; it would receive cash only upon warrant exercises. If all warrants are exercised for cash, aggregate gross proceeds would be approximately $12,857,224.

The selling stockholder may sell shares over time using various methods described under “Plan of Distribution.” Aqua Metals’ common stock trades on Nasdaq as “AQMS,” with a last reported price of $10.0533 per share on October 23, 2025. Shares outstanding were 2,982,762 as of October 22, 2025. The prospectus highlights risks including stock price volatility and notes that the auditor’s report includes an explanatory paragraph regarding substantial doubt about the company’s ability to continue as a going concern.

Positive

• None.

Negative

• Auditor going concern: The independent auditor’s report includes an explanatory paragraph regarding substantial doubt about the company’s ability to continue as a going concern.

Insights

Equity capital markets analyst

Resale S-3 with warrants; cash only if exercised; going concern noted.

This registration covers up to 1,133,794 shares for resale, issuable upon warrants with a $11.34 strike, expiring on October 16, 2030. The issuer explicitly receives no proceeds from resales; cash inflow occurs only if the holder exercises the warrants for cash, which is at the holder’s discretion.

The filing quantifies potential gross proceeds of about $12,857,224 upon full cash exercise. Actual proceeds depend on market price relative to the strike and holder decisions, and the warrants permit cashless exercise, which would generate no cash to the company.

Risk disclosure is notable: the independent auditor’s report includes an explanatory paragraph about substantial doubt regarding going concern. While this does not change the mechanics of the resale, it underscores liquidity and funding risk pending future capital or operational progress. Subsequent filings may update these conditions.

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As filed with the Securities and Exchange Commission on October 24, 2025

Registration No. 333-            .

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-3

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

Aqua Metals, Inc.

(Exact name of registrant as specified in its charter)

Delaware		47-1169572
(State of incorporation)		(I.R.S. Employer Identification No.)
5370 Kietzke Lane, Suite 201 Reno, Nevada 89511 (775) 446-4418 (Address and telephone number of registrant’s principal executive offices)
Stephen Cotton Chief Executive Officer Aqua Metals, Inc. 5370 Kietzke Lane, Suite 201 Reno, Nevada 89511 (775) 446-4418 (Name, address and telephone number of agent for service) Copy to: Daniel K. Donahue Greenberg Traurig, LLP 18565 Jamboree Road, Suite 500 Irvine, California 92612 (949) 732-6500
Approximate date of commencement of proposed sale to the public: From time to time after the effective date of this registration statement.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box: ☐

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box: ☒

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering ☐

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If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box.  ☐

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box.  ☐  

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of a “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer                   ☐	Accelerated filer                                     ☐
Non-accelerated filer                     ☒	Smaller reporting company                    ☒
	Emerging growth company                    ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐

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The information in this prospectus is not complete and may be changed without notice. We may not sell these securities until the registration statement relating to these securities has been declared effective by the Securities and Exchange Commission. This prospectus is neither an offer to sell nor a solicitation of an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

SUBJECT TO COMPLETION, DATED OCTOBER 24, 2025

PROSPECTUS

1,133,794 Common Stock

Issuable Upon Exercise of Certain Common Stock Purchase Warrants

This prospectus relates to the offer and resale of up to an aggregate of 1,133,794 shares (the “Shares”) of common stock, par value $0.001 per share (the “Common Stock”), of Aqua Metals, Inc., a Delaware corporation (the “Company”), issuable upon the exercise of certain common stock purchase warrants (“Warrants”) dated October 16, 2025. The Shares may be sold from time to time by the Selling Stockholder named in this prospectus (the “Selling Stockholder”).

The Warrants were issued to the Selling Stockholder on October 16, 2025 pursuant to that certain securities purchase agreement dated October 15, 2025 between the Company and the Selling Stockholder. Each Warrant allows the Selling Stockholder to purchase one Share at an exercise price of $11.34 per Share, however the Warrants may be exercised, in certain circumstances, on a cashless basis pursuant to the formula contained in the Warrants. The Warrants expire on October 16, 2030.

The Warrants may be exercised by the Selling Stockholder at any time and the Selling Stockholder may offer, resell or dispose of the Shares, or interests therein, from time to time as it may determine through public or private transactions, to or through underwriters, broker-dealers or agents, or through any other means described in the section of this prospectus entitled “Plan of Distribution”. We do not know when or in what amounts the Selling Stockholder may exercise the Warrants or offer the Shares for sale. The prices at which the Selling Stockholder may sell the Shares may be at fixed prices, at prevailing market prices at the time of sale, or at prices negotiated with purchasers.

The Selling Stockholder will bear its own commissions and discounts, if any, attributable to the sale or disposition of the Shares or interests therein. We will bear all costs, expenses, and fees in connection with the registration of the resale of the Shares. While we will not receive any of the proceeds from the sale of the Shares by the Selling Stockholder, we will receive $11.34 per Share upon the cash exercise of each Warrant. Upon the cash exercise of all Warrants, we will receive aggregate gross proceeds of approximately $12,857,224. However, we cannot predict when and in what amounts or if the Warrants will be exercised for cash, and it is possible that the Warrants may expire and never be exercised or be exercised, if at all, only on a cashless basis, in which case we would not receive any cash proceeds. 

Our Common Stock is listed on The NASDAQ Capital Market under the symbol “AQMS”. On October 23, 2025, the last reported sale price of our Common Stock on The NASDAQ Capital Market was $10.0533 per share.

Investing in our Common Stock involves significant risks. See “Risk Factors” beginning on page 3 of this prospectus and in the documents incorporated by reference in this prospectus for a discussion of the factors you should carefully consider before deciding to purchase our Common Stock.

Neither the U.S. Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense.

The date of this prospectus is                      , 2025.

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ABOUT THIS PROSPECTUS	ii
ABOUT AQUA METALS, INC.	1
THE OFFERING	2
RISK FACTORS	3
NOTE REGARDING FORWARD-LOOKING STATEMENTS	5
REASONS FOR THE OFFER AND USE OF PROCEEDS	6
SELLING STOCKHOLDER	7
PLAN OF DISTRIBUTION	8
DESCRIPTION OF OUR COMMON STOCK	9
LEGAL MATTERS	10
EXPERTS	10
WHERE YOU CAN FIND MORE INFORMATION	10
INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE	11
INDEMNIFICATION OF DIRECTORS AND OFFICERS	12

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ABOUT THIS PROSPECTUS

This prospectus describes the general manner in which the Selling Stockholder may offer from time to time up to 1,133,794 shares of Common Stock. You should rely only on the information contained in this prospectus and the related exhibits, any prospectus supplement or amendment thereto and the documents incorporated by reference, or to which we have referred you, before making your investment decision. Neither we nor the Selling Stockholder has authorized anyone to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. This prospectus, any prospectus supplement or amendments thereto do not constitute an offer to sell, or a solicitation of an offer to purchase, the shares of Common Stock offered by this prospectus, any prospectus supplement or amendments thereto in any jurisdiction to or from any person to whom or from whom it is unlawful to make such offer or solicitation of an offer in such jurisdiction. You should not assume that the information contained in this prospectus, any prospectus supplement or amendments thereto, as well as information we have previously filed with the U.S. Securities and Exchange Commission (the “SEC”), is accurate as of any date other than the date on the front cover of the applicable document.

If necessary, the specific manner in which the shares of Common Stock may be offered and sold will be described in a supplement to this prospectus, which supplement may also add, update or change any of the information contained in this prospectus. To the extent there is a conflict between the information contained in this prospectus and any prospectus supplement, you should rely on the information in such prospectus supplement, provided that if any statement in one of these documents is inconsistent with a statement in another document having a later date, the statement in the document having the later date modifies or supersedes the earlier statement.

Neither the delivery of this prospectus nor any distribution of shares of Common Stock pursuant to this prospectus shall, under any circumstances, create any implication that there has been no change in the information set forth or incorporated by reference into this prospectus or in our affairs since the date of this prospectus. Our business, financial condition, results of operations and prospects may have changed since such date.

Unless the context otherwise indicates, references in this prospectus to the “Company,” “we,” “our” and “us” refer, collectively, to Aqua Metals, Inc., a Delaware corporation, and its subsidiaries.

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ABOUT AQUA METALS, INC.

Aqua Metals is seeking to reinvent metal recycling with its patented and patent-pending AquaRefining™ technologies. Aqua Metals is focused on developing cleaner and safer metals recycling through innovation. We believe Aqua Metals can expand the development of breakthrough technologies for sustainable metal recycling and deliver high-value critical minerals back into the manufacturing supply chain while reducing emissions and toxic byproducts and creating much safer work environments.

Aqua Metals has invested in breakthrough metals recycling methodologies that we believe are environmentally responsible, economically competitive, and will help retain critical strategic metals within the U.S. while enabling domestically produced, sustainably produced, recycled metals to enter the supply chain and lower sole reliance on unsafe and toxic mining operations. Since 2015, Aqua Metals has developed breakthrough metal recycling technologies that utilize a clean, closed-loop process that can produce ultra-high purity metals. AquaRefining is designed to deliver raw materials back into the manufacturing supply chain, and replaces the need for polluting furnaces and hazardous chemicals with electricity-powered electroplating to recover valuable metals and materials from spent batteries with higher purity, lower emissions, and minimal waste.

We believe Aqua Metals’ regenerative electro-hydrometallurgical recycling method potentially offers a substantial improvement over traditional pyrometallurgical and hydrometallurgical recycling techniques, which produce much higher emissions, lower recovery rates, and significant landfill waste. We believe the AquaRefining process has the potential to vastly reduce the environmental impact of recycling lithium batteries as compared to other processes while providing a higher yield of high-purity metals essential for the burgeoning US battery manufacturing industry. 

We are in the process of demonstrating that Li AquaRefining can create the highest quality and highest yields of recovered minerals from lithium-ion batteries, with lower waste streams and lower costs than alternatives. With the proven ability to recover valuable metals from lithium-ion batteries at our pilot facility in the TRIC, our goal is to demonstrate our ability to process commercial quantities of high-purity lithium hydroxide and/or carbonate, nickel, cobalt, manganese dioxide, and copper in pure forms that can be sold to the general metals and superalloy markets, and can be made into battery precursor compound materials with proven processes that are already used in the battery industry.

The Company is also exploring additional innovative applications of AquaRefining across metals recycling industries at our Innovation Center, including recycling emerging battery chemistries and opportunities to develop additional products for sale to customer specifications.

Our principal executive offices are located at 5370 Kietzke Lane, Suite 201, Reno, Nevada 89511, and our telephone number is (775) 446-4418.

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THE OFFERING

This prospectus relates to the resale of up to an aggregate of 1,133,794 shares of our Common Stock that may be sold from time to time by the Selling Stockholder named in this prospectus.

Shares of Common Stock outstanding immediately prior to the offering		Up to 2,982,762 shares
Shares of Common Stock offered by the Selling Stockholder		1,133,794 shares
Use of Proceeds		We will not receive any of the proceeds from the sale of the shares of our Common Stock by the Selling Stockholder pursuant to this prospectus. We may receive up to $12,857,224 from the exercise of the Warrants. Any proceeds that we receive from the exercise of the Warrants will be used for working capital and general corporate purposes. See “Reasons for the Offer and Use of Proceeds.”
Risk Factors		Investing in shares of our Common Stock involves a high degree of risk. See “Risk Factors” on page 3 of this prospectus and under similar sections in the documents we incorporate by reference into this prospectus for a discussion of factors you should consider carefully before making an investment decision.
Nasdaq Stock Market Symbol		“AQMS”

The number of shares of Common Stock to be outstanding prior to the offering is based on 2,982,762 shares of Common Stock outstanding as of October 22, 2025, and excludes the following:

● 255,480 shares of our Common Stock issuable upon vesting of outstanding restricted stock units as of October 22, 2025;

● 43,578 shares of Common Stock reserved for issuance and available for future grant under our 2019 Stock Incentive Plan as of October 22, 2025;

● 23,738 shares of Common Stock reserved for issuance under our Officer and Director Share Purchase Plan as of October 22, 2025; and

● 73,122 shares of Common Stock reserved for issuance under our 2022 Employee Stock Purchase Plan as October 22, 2025.

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RISK FACTORS

Investing in our securities involves a high degree of risk. Before investing in our securities, you should carefully consider the risks, uncertainties and assumptions contained in this prospectus and also contained under the heading ”Risk Factors” included in our Annual Report on Form 10-K for the year ended December 31, 2024 filed with the SEC on March 31, 2025, as revised or supplemented by subsequent filings, which are on file with the SEC and are incorporated herein by reference, and which may be amended, supplemented or superseded from time to time by other reports we file with the SEC in the future. Our business, financial condition, results of operations and future growth prospects could be materially and adversely affected by any of these risks. In these circumstances, the market price of our Common Stock could decline, and you may lose all or part of your investment.

Risks Related to this Offering and Our Common Stock

As an investor, you may lose all of your investment.

Investing in our securities involves a high degree of risk. As an investor, you may never recoup all, or even part, of your investment and you may never realize any return on your investment. You must be prepared to lose all of your investment.

The market price of our shares may be subject to fluctuation and volatility. 

You could lose all or part of your investment. The market price of our Common Stock is subject to wide fluctuations in response to various factors, some of which are beyond our control. The market price for our Common Stock varied between a high of $39.36 and a low of $3.46 in the twelve-month period ended October 23, 2025. The market price of our shares on the Nasdaq Capital Market may fluctuate as a result of a number of factors, some of which are beyond our control, including, but not limited to:

● actual or anticipated variations in our and our competitors’ results of operations and financial condition;

● general economic and market conditions and other factors, including factors unrelated to our operating performance, such adverse impact of tariffs and any trade war;

● market acceptance of our product candidates;

● changes in earnings estimates or recommendations by securities analysts, if our shares are covered by analysts;

● the lack of market acceptance and sales growth for our drug candidates, if any, that receive marketing approval;

● development of technological innovations or new competitive products by others;

● announcements of technological innovations or new products by us;

● developments concerning intellectual property rights, including our involvement in litigation brought by or against us;

● regulatory developments and the decisions of regulatory authorities as to the approval or rejection of new or modified products;

● changes in the amounts that we spend to develop, acquire or license new products, technologies or businesses;

● changes in our expenditures to promote our product candidates;

● our sale or proposed sale, or the sale by our significant stockholders, of our shares or other securities in the future;

● changes in key personnel; and

● the trading volume of our shares.

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The Selling Stockholder may choose to sell the Shares at prices below the current market price.

The Selling Stockholder is not restricted as to the prices at which they may sell or otherwise dispose of the Shares covered by this prospectus. Sales or other dispositions of the Shares below the then-current market prices could adversely affect the market price of our Common Stock.

Future sales and issuances of our Common Stock could result in additional dilution of the percentage ownership of our stockholders and could cause our share price to fall.

We expect that significant additional capital will be needed in the future to continue our planned operations. To the extent we raise additional capital by issuing equity securities, our stockholders may experience substantial dilution. We may sell Common Stock, convertible securities or other equity securities in one or more transactions at prices and in a manner we determine from time to time. If we sell Common Stock, convertible securities or other equity securities in more than one transaction, investors may be materially diluted by subsequent sales. Such sales may also result in material dilution to our existing stockholders, and new investors could gain rights superior to our existing stockholders.

We have not paid dividends in the past and have no immediate plans to pay dividends.

We plan to reinvest all of our earnings, to the extent we have earnings, to cover operating costs and otherwise become and remain competitive. We do not plan to pay any cash dividends with respect to our securities in the foreseeable future. We cannot assure you that we would, at any time, generate sufficient surplus cash that would be available for distribution to the holders of our Common Stock as a dividend. Therefore, you should not expect to receive cash dividends on our Common Stock. 

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NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus contains, and any accompanying prospectus supplement will contain, forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, and the Private Securities Litigation Reform Act of 1993. Also, documents that we incorporate by reference into this prospectus, including documents that we subsequently file with the SEC, will contain forward-looking statements. Forward-looking statements are those that predict or describe future events or trends and that do not relate solely to historical matters. You can generally identify forward-looking statements as statements containing the words “may,” “will,” “could,” “should,” “expect,” “anticipate,” “intend,” “estimate,” “believe,” “project,” “plan,” “assume” or other similar expressions, or negatives of those expressions, although not all forward-looking statements contain these identifying words. All statements contained or incorporated by reference in this prospectus and any prospectus supplement regarding our business strategy, future operations, projected financial position, potential strategic transactions, proposed licensing arrangements, projected sales growth, estimated future revenues, cash flows and profitability, projected costs, potential outcome of litigation, potential sources of additional capital, future prospects, future economic conditions, the future of our industry and results that might be obtained by pursuing management’s current plans and objectives are forward-looking statements.

You should not place undue reliance on our forward-looking statements because the matters they describe are subject to certain risks, uncertainties and assumptions that are difficult to predict. Our forward-looking statements are based on the information currently available to us and speak only as of the date on the cover of this prospectus, the date of any prospectus supplement, or, in the case of forward-looking statements incorporated by reference, the date of the filing that includes the statement. Over time, our actual results, performance or achievements may differ from those expressed or implied by our forward-looking statements, and such difference might be significant and materially adverse to our security holders. Except as required by law, we undertake no obligation to update publicly any forward-looking statements, whether as a result of new information, future events or otherwise.

We have identified some of the important factors that could cause future events to differ from our current expectations and they are described in this prospectus and supplements to this prospectus under the caption “Risk Factors,” as well as in our most recent Annual Report on Form 10-K, including under the captions “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” and in other documents that we may file with the SEC, all of which you should review carefully. Please consider our forward-looking statements in light of those risks as you read this prospectus and any prospectus supplement.

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REASONS FOR THE OFFER AND USE OF PROCEEDS

We are required under the terms of the securities purchase agreement, dated October 15, 2025, by and between our Company and the Selling Stockholder to file a registration statement, of which this prospectus is a part, to cover the resale of the Shares issuable upon the exercise of certain common stock purchase warrants (“Warrants”) dated October 16, 2025, which were issued to the Selling Stockholder pursuant to the securities purchase agreement.

The shares of our Common Stock being offered by this prospectus are solely for the account of the Selling Stockholder. While we will not receive any of the proceeds from the sale of the Shares by the Selling Stockholder pursuant to this prospectus, we will receive $11.34 per Share upon the cash exercise of each Warrant. Upon the cash exercise of all Warrants, we will receive aggregate gross proceeds of approximately $12,857,224. However, we cannot predict when and in what amounts or if the Warrants will be exercised for cash, and it is possible that the Warrants may expire and never be exercised or be exercised, if at all, only on a cashless basis, in which case we would not receive any cash proceeds. Any proceeds from the exercise of the Warrants will be used for working capital and general corporate purposes.

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SELLING STOCKHOLDER

We are registering the resale of an aggregate of 1,133,794 shares of our Common Stock (the “Shares”) by the Selling Stockholder named below issuable upon the exercise of certain common stock purchase warrants (“Warrants”) dated October 16, 2025. The Warrants were issued to the Selling Stockholder on October 16, 2025 pursuant to that certain securities purchase agreement dated October 15, 2025 between the Company and the Selling Stockholder. Under the securities purchase agreement, we agreed to file a registration statement, of which this prospectus is a part, covering the resale of the Shares.

Each Warrant allows the Selling Stockholder to purchase one Share at an exercise price of $11.34 per Share, however the Warrants may be exercised, in certain circumstances, on a cashless basis pursuant to the formula contained in the Warrants. The Warrants expire on October 16, 2030.

The Warrants may be exercised by the Selling Stockholder at any time and the Selling Stockholder may offer, resell or dispose of the Shares, or interests therein, from time to time as it may determine through public or private transactions, to or through underwriters, broker-dealers or agents, or through any other means described in “Plan of Distribution”. We do not know when or in what amounts the Selling Stockholder may exercise the Warrants or offer the Shares for sale. The prices at which the Selling Stockholder may sell the Shares may be at fixed prices, at prevailing market prices at the time of sale, or at prices negotiated with purchasers.

The following table sets forth:

● the name and address of the Selling Stockholder,

● the number of shares of Common Stock that the Selling Stockholder beneficially owned prior to the offering for resale of the Shares under this prospectus,

● the maximum number of Shares that may be offered for resale for the account of the Selling Stockholder under this prospectus, and

● the number and percentage of shares of Common Stock to be beneficially owned by the Selling Stockholder after the offering and sale of the Shares (assuming all of the offered Shares are sold by the Selling Stockholder pursuant to this prospectus).

None of the Selling Stockholder or its affiliates has been an officer or director of our Company or any of our predecessors or affiliates within the last three years, nor has the Selling Stockholder had a material relationship with us within the last three years, other than pursuant to the transactions contemplated by the securities purchase agreement.

The Selling Stockholder may offer for sale all or part of the Shares from time to time. The table below assumes that the Selling Stockholder will sell all of the Shares offered for sale. The Selling Stockholder is under no obligation, however, to sell any Shares pursuant to this prospectus. 

Beneficial ownership is determined in accordance with the rules and regulations of the SEC. In computing the number of shares beneficially owned by the Selling Stockholder and the percentage ownership of the Selling Stockholder, securities that are currently convertible or exercisable into shares of our Common Stock, or convertible or exercisable within 60 days following the date of this prospectus, are deemed beneficially owned by the Selling Stockholder.

Name of Selling Stockholder		Number of Shares of Common Stock Beneficially Owned Prior to Offering				Maximum Number of Shares to be Sold				Number of Shares of Common Stock Beneficially Owned After the Offering				Percentage Ownership After Offering
Hudson Bay Master Fund Ltd.(1) c/o Hudson Bay Capital Management LP 290 Harbor Drive, Fl 3 Stamford, CT 06902			1,133,794				1,133,794				-				-	%

⁽¹⁾ Hudson Bay Capital Management LP, the investment manager of Hudson Bay Master Fund Ltd., has voting and investment power over these securities. Sander Gerber is the managing member of Hudson Bay Capital GP LLC, which is the general partner of Hudson Bay Capital Management LP. Each of Hudson Bay Master Fund Ltd. and Sander Gerber disclaims beneficial ownership over these securities. Hudson Bay Master Fund Ltd. is not a licensed broker dealer or affiliated with a licensed broker dealer.

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PLAN OF DISTRIBUTION

The Shares offered by this prospectus are being offered by the Selling Stockholder. The Shares may be sold or distributed from time to time by the Selling Stockholder directly to one or more purchasers or through brokers, dealers, or underwriters who may act solely as agents at market prices prevailing at the time of sale, at prices related to the prevailing market prices, at negotiated prices, or at fixed prices, which may be changed. The sale of the Shares offered by this prospectus could be effected in one or more of the following methods:

● ordinary brokers’ transactions;

● transactions involving cross or block trades;

● through brokers, dealers, or underwriters who may act solely as agents;

● “at the market” into an existing market for the shares of our Common Stock;

● in other ways not involving market makers or established business markets, including direct sales to purchasers or sales effected through agents;

● in privately negotiated transactions; or

● any combination of the foregoing.

In order to comply with the securities laws of certain states, if applicable, the Shares offered by this prospectus may be sold only through registered or licensed brokers or dealers. In addition, in certain states, the shares of our Common Stock offered by this prospectus may not be sold unless they have been registered or qualified for sale in the state or an exemption from the state’s registration or qualification requirement is available and complied with.

Brokers, dealers, underwriters or agents participating in the distribution of the Shares of our Common Stock offered by this prospectus may receive compensation in the form of commissions, discounts, or concessions from the purchasers, for whom the broker-dealers may act as agent, of shares of our Common Stock sold by the Selling Stockholder through this prospectus. The compensation paid to any such particular broker-dealer by any such purchasers of Shares sold by the Selling Stockholder may be less than or in excess of customary commissions. Neither we nor the Selling Stockholder can presently estimate the amount of compensation that any agent will receive from any purchasers of Shares sold by the Selling Stockholder.

We know of no existing arrangements between the Selling Stockholder or any other stockholder, broker, dealer, underwriter or agent relating to the sale or distribution of the Shares offered by this prospectus.

We may from time to time file with the SEC one or more supplements to this prospectus or amendments to the registration statement of which this prospectus is a part to amend, supplement or update information contained in this prospectus, including, if and when required under the Securities Act, to disclose certain information relating to a particular sale of Shares offered by this prospectus by the Selling Stockholder, including the names of any brokers, dealers, underwriters or agents participating in the distribution of such shares of our Common Stock by the Selling Stockholder, any compensation paid by the Selling Stockholder to any such brokers, dealers, underwriters or agents, and any other required information.

We will pay the expenses incident to the registration under the Securities Act of the offer and sale of the Shares included in this prospectus by the Selling Stockholder. We estimate that the total expenses for the offering will be approximately $30,000.

We have agreed to indemnify the Selling Stockholder and certain other persons against certain liabilities in connection with the offering of Shares offered by this prospectus, including liabilities arising under the Securities Act or, if such indemnity is unavailable, to contribute amounts required to be paid in respect of such liabilities.

We have advised the Selling Stockholder that it is required to comply with Regulation M promulgated under the Exchange Act. With certain exceptions, Regulation M precludes the Selling Stockholder, any affiliated purchasers, and any broker-dealer or other person who participates in the distribution from bidding for or purchasing, or attempting to induce any person to bid for or purchase any security which is the subject of the distribution until the entire distribution is complete. Regulation M also prohibits any bids or purchases made in order to stabilize the price of a security in connection with the distribution of that security. All of the foregoing may affect the marketability of the securities offered by this prospectus.

This offering will terminate on the date that all shares of our Common Stock offered by this prospectus have been sold by the Selling Stockholder.

Our Common Stock is currently listed on The Nasdaq Capital Market under the symbol “AQMS”.

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DESCRIPTION OF OUR COMMON STOCK

The Selling Stockholder is offering for resale up to an aggregate of 1,133,794 shares of Common Stock.

Our First Amended and restated Certificate of Incorporation, as amended to date, authorizes the issuance of up to 300,000,000 shares of Common Stock. Holders of shares of Common Stock are entitled to one vote per share on all matters to be voted upon by the stockholders generally. Stockholders are entitled to receive such dividends as may be declared from time to time by the board of directors out of funds legally available therefor, and in the event of liquidation, dissolution or winding up of the Company to share ratably in all assets remaining after payment of liabilities. The holders of shares of Common Stock have no preemptive, conversion, subscription or cumulative voting rights.

Additional terms of our shares of Common Stock are contained in our First Amended and restated Certificate of Incorporation and our Third Amended and Restated Bylaws, each as amended to date. For a description of our Common Stock, see our Registration Statement on Form 8-A12B, filed with the SEC on July 24, 2015 under Section 12(b) of the Exchange Act, including any amendments or reports filed for the purpose of updating such description.

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LEGAL MATTERS

The validity of the issuance of the securities offered by this prospectus has been passed upon for us by Greenberg Traurig, LLP, Irvine, California.

EXPERTS

The consolidated financial statements of Aqua Metals, Inc. as of December 31, 2024 and 2023 and for the fiscal years then ended, have been audited by Forvis Mazars, LLP, independent registered public accounting firm, as set forth in their report thereon, included in Aqua Metals, Inc.’s Annual Report on Form 10-K for the fiscal year ended December 31, 2024, and incorporated herein by reference. Such consolidated financial statements have been incorporated herein by reference in reliance upon such report given on the authority of such firm as experts in accounting and auditing. The report of Forvis Mazars, LLP contains an explanatory paragraph regarding substantial doubt about the Company’s ability to continue as a going concern.

WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and current reports and other information with the SEC. You may read and copy any document we file at the SEC’s Public Reference Room located at 100 F Street, N.E., Washington, D.C. 20549. You may obtain information on the operation of the public reference room by calling the SEC at 1-800-SEC-0330. Our filings with the SEC also are available from the SEC’s internet site at http://www.sec.gov, which contains reports, proxy and information statements, and other information regarding issuers that file electronically.

This prospectus is part of a registration statement that we filed with the SEC. As permitted by SEC rules, this prospectus and any accompanying prospectus supplement that we may file, which form a part of the registration statement, do not contain all of the information that is included in the registration statement. The registration statement contains more information regarding us and our securities, including certain exhibits. You can obtain a copy of the registration statement from the SEC at the address listed above or from the SEC’s website.

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INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

The SEC permits us to “incorporate by reference” the information and reports we file with it. This means that we can disclose important information to you by referring to another document. The information that we incorporate by reference is considered to be part of this prospectus, and later information that we file with the SEC automatically updates and supersedes this information. We incorporate by reference the documents listed below, except to the extent information in those documents is different from the information contained in this prospectus, and all future documents filed with the SEC under Sections 13(a), 13(c), 14, or 15(d) of the Exchange Act (other than the portions thereof deemed to be furnished to the SEC) until we terminate the offering of these securities:

● our Annual Report on Form 10-K for the fiscal year ended December 31, 2024, filed with the SEC on March 31, 2025;

● our Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2025, filed with the SEC on May 8, 2025;

● Our Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2025, filed with the SEC on August 13, 2025;

● our Current Reports on Form 8-K, filed with the SEC on May 1, 2025, May 13, 2025, May 16, 2025, May 16, 2025, May 29, 2025, June 13, 2025, July 3, 2025, July 24, 2025, September 8, 2025 and October 16, 2025; and

● the description of our Common Stock in our Form 8-A12B, which was filed with the SEC on July 24, 2015, and any amendments or reports filed for the purpose of updating this description.

To the extent that any statement in this prospectus is inconsistent with any statement that is incorporated by reference and that was made on or before the date of this prospectus, the statement in this prospectus shall supersede such incorporated statement. The incorporated statement shall not be deemed, except as modified or superseded, to constitute a part of this prospectus or the registration statement. Statements contained in this prospectus as to the contents of any contract or other document are not necessarily complete and, in each instance, we refer you to the copy of each contract or document filed as an exhibit to our various filings made with the SEC.

You may request a copy of these filings, at no cost, by writing or telephoning us at the following address or telephone number:

Aqua Metals, Inc.
Attn: Investor Relations
5370 Kietzke Lane, Suite 201,

Reno, Nevada 89511

(775) 446-4418

You may also access these filings on our website at www.aquametals.com. Except for the specific incorporated documents listed above, no information available on or through our website shall be deemed to be incorporated in this prospectus or the registration statement of which it forms a part.

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INDEMNIFICATION OF DIRECTORS AND OFFICERS

The Delaware General Corporation Law provides that corporations may include a provision in their certificate of incorporation relieving directors of monetary liability for breach of their fiduciary duty as directors, provided that such provision shall not eliminate or limit the liability of a director (i) for any breach of the director’s duty of loyalty to the corporation or its stockholders, (ii) for acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of law, (iii) for unlawful payment of a dividend or unlawful stock purchase or redemption, or (iv) for any transaction from which the director derived an improper personal benefit. Our amended and restated certificate of incorporation provides that directors are not liable to us or our stockholders for monetary damages for breach of their fiduciary duty as directors to the fullest extent permitted by Delaware law. In addition to the foregoing, our amended and restated certificate of incorporation provides that we may indemnify directors and officers to the fullest extent permitted by law and we have entered into indemnification agreements with each of our directors and executive officers.

The above provisions in our First Amended and restated Certificate of Incorporation, as amended to date, may have the effect of reducing the likelihood of derivative litigation against directors and may discourage or deter stockholders or management from bringing a lawsuit against directors for breach of their fiduciary duty, even though such an action, if successful, might otherwise have benefited us and our stockholders. However, we believe that the foregoing provisions are necessary to attract and retain qualified persons as directors.

Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to our directors, officers and controlling persons pursuant to the foregoing provisions, or otherwise, we have been advised that in the opinion of the SEC, such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable.

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1,133,794 Common Stock

PROSPECTUS

                          , 2025

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PART II.

INFORMATION NOT REQUIRED IN PROSPECTUS

Item 14.                  Other Expenses of Issuance and Distribution

The estimated expenses in connection with the issuance and distribution of the securities being registered, all of which will be borne by us, are set forth in the following itemized table*:

SEC Registration Fee		1,530
Printing Fees and Expenses			1,000
Legal Fees and Expenses			20,000
Accounting Fees and Expenses		5,000
Transfer Agent Fees and Expenses			1,000
Miscellaneous Fees and Expenses		1,470
Total		30,000

Item 15.                  Indemnification of Directors and Officers

We are incorporated under the laws of the State of Delaware. Section 145 of the Delaware General Corporation Law, or DGCL, provides that a Delaware corporation may indemnify any persons who are, or are threatened to be made, parties to any threatened, pending or completed action, suit or proceeding, whether civil, criminal, administrative or investigative (other than an action by or in the right of such corporation), by reason of the fact that such person was an officer, director, employee or agent of such corporation, or is or was serving at the request of such corporation as an officer, director, employee or agent of another corporation or enterprise. The indemnity may include expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by such person in connection with such action, suit or proceeding, provided that such person acted in good faith and in a manner he or she reasonably believed to be in or not opposed to the corporation’s best interests and, with respect to any criminal action or proceeding, had no reasonable cause to believe that his or her conduct was illegal. Section 145 of the DGCL further authorizes a corporation to purchase and maintain insurance on behalf of any indemnified person against any liability asserted against and incurred by such person in any indemnified capacity, or arising out of such person’s status as such, regardless of whether the corporation would otherwise have the power to indemnify such person under the DGCL.

Section 102(b)(7) of the DGCL permits a corporation to provide in its certificate of incorporation that a director of the corporation shall not be personally liable to the corporation or its stockholders for monetary damages for breach of fiduciary duties as a director, except for liability for any:

● breach of a director’s duty of loyalty to the corporation or its stockholders;

● act or omission not in good faith or that involves intentional misconduct or a knowing violation of law;

● unlawful payment of dividends or redemption of shares; or

● transaction from which the director derives an improper personal benefit.

Our amended and restated certificate of incorporation authorizes us to, and our amended and restated bylaws provide that we must, indemnify our directors and officers to the fullest extent authorized by the DGCL and also pay expenses incurred in defending any such proceeding in advance of its final disposition upon delivery of an undertaking, by or on behalf of an indemnified person, to repay all amounts so advanced if it should be determined ultimately that such person is not entitled to be indemnified under this section or otherwise.

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As permitted by the DGCL, we have entered into indemnification agreements with each of our directors and certain of our officers. These agreements require us to indemnify these individuals to the fullest extent permitted under Delaware law against liabilities that may arise by reason of their service to us, and to advance expenses incurred as a result of any proceeding against them as to which they could be indemnified.

We have an insurance policy covering our officers and directors with respect to certain liabilities, including liabilities arising under the Securities Act or otherwise.

Any underwriting agreement or similar agreement that we enter into in connection with an offer of securities pursuant to this registration statement may provide for indemnification by any underwriters of us, our directors, our officers who sign the registration statement and our controlling persons for some liabilities, including liabilities arising under the Securities Act of 1933.

Insofar as the forgoing provisions permit indemnification of directors, executive officers, or persons controlling us for liability arising under the Securities Act we have been informed that, in the opinion of the SEC, such indemnification is against public policy as expressed in the Securities Act and is therefore unenforceable.

Item 16.          Exhibits

Exhibit No.		Description		Method of Filing
4.1		First Amended and Restated Certificate of Incorporation of the Registrant		Incorporated by reference from the Registrant’s Registration Statement on Form S-1 filed on June 9, 2015
4.2		Third Amended and Restated Bylaws of the Registrant		Incorporated by reference from the Registrant’s Current Report on Form 8-K filed on January 21, 2022
4.3		Certificate of Amendment to First Amended and Restated Certificate of Incorporation of the Registrant		Incorporated by reference from the Registrant’s Registration Statement on Form S-1 filed on June 25, 2015
4.4		Certificate of Amendment to First Amended and Restated Certificate of Incorporation of the Registrant		Incorporated by reference from the Registrant’s Quarterly Report on Form 10-Q filed on May 9, 2019
4.5		Certificate of Amendment to First Amended and Restated Certificate of Incorporation of the Registrant		Incorporated by reference from the Registrant’s Quarterly Report on Form 10-Q filed on July 21, 2022
4.6		Certificate of Amendment to First Amended and Restated Certificate of Incorporation of the Registrant		Incorporated by reference from the Registrant’s Current Report on Form 8-K filed on November 1, 2024
4.7		Certificate of Amendment to First Amended and Restated Certificate of Incorporation of the Registrant		Incorporated by reference from the Registrant’s Quarterly Report on Form 10-Q filed on August 13, 2025
4.8		Amendment No. 1 to Third Amended and Restated Bylaws of the Registrant		Incorporated by reference from the Registrant’s Current Report on Form 8-K filed on June 13, 2025
5.1		Opinion of Greenberg Traurig, LLP		Filed electronically herewith
23.1		Consent of Forvis Mazars, LLP		Filed electronically herewith

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23.2		Consent of Greenberg Traurig, LLP (included in Exhibit 5.1)		Filed electronically herewith
24.1		Power of Attorney (included on the signature page to this registration statement)		Filed electronically herewith
107		Filing Fee Table		Filed electronically herewith

Item 17.          Undertakings

The undersigned registrant hereby undertakes:

(1)         To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(i) To include any prospectus required by Section 10(a)(3) of the Securities Act;

(ii) To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20 percent change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement; and

(iii) To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement;

provided, however, that paragraphs (i), (ii) and (iii) do not apply if the registration statement is on Form S-3 and the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Commission by the registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in the registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the registration statement.

(2)         That, for the purpose of determining any liability under the Securities Act of 1933, each such post- effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3)         To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

(4)         That, for the purpose of determining liability under the Securities Act of 1933 to any purchaser:

(i) Each prospectus filed by the registrant pursuant to Rule 424(b)(3) shall be deemed to be part of the registration statement as of the date the filed prospectus was deemed part of and included in the registration statement; and

(ii) Each prospectus required to be filed pursuant to Rule 424(b)(2), (b)(5) or (b)(7) as part of a registration statement in reliance on Rule 430B relating to an offering made pursuant to Rule 415(a)(1)(i), (vii) or (x) for the purpose of providing the information required by Section 10(a) of the Securities Act shall be deemed to be part of and included in the registration statement as of the earlier of the date such form of prospectus is first used after effectiveness or the date of the first contract of sale of securities in the offering described in prospectus. As provided in Rule 430B, for liability purposes of the issuer and any person that is at that date an underwriter, such date shall be deemed to be a new effective date of the registration statement relating to the securities in the registration statement to which the prospectus relates, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof. Provided, however, that no statement made in a registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such effective date, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such effective date, or

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(5)         That, for the purpose of determining liability of the registrant under the Securities Act to any purchaser in the initial distribution of the securities, the undersigned registrant undertakes that in a primary offering of securities of the undersigned registrant pursuant to this registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the undersigned registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser:

(i) Any preliminary prospectus or prospectus of the undersigned registrant relating to the offering required to be filed pursuant to Rule 424;

(ii) Any free writing prospectus relating to the offering prepared by or on behalf of the undersigned registrant or used or referred to by the undersigned Registrant;

(iii) The portion of any other free writing prospectus relating to the offering containing material information about the undersigned registrant or its securities provided by or on behalf of an undersigned registrant; and

(iv) Any other communication that is an offer in the offering made by the undersigned registrant to the purchaser.

(6)         That, for purposes of determining any liability under the Securities Act, each filing of the registrant’s annual report pursuant to Section 13(a) or Section 15(d) of the Exchange Act of 1934 that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(7)         Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers, and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that, in the opinion of the Securities and Exchange Commission, such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer, or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act and will be governed by the final adjudication of such issue.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in Reno, Nevada on October 24, 2025.

	AQUA METALS, INC.
	By:	/s/ Stephen Cotton
		Stephen Cotton
		Chief Executive Officer

POWER OF ATTORNEY

Each person whose signature appears below hereby constitutes and appoints Stephen Cotton and Eric West, and each of them, as such person’s true and lawful attorney-in-fact and agent, each with full powers of substitution and re-substitution, for such person and in such person’s name, place and stead, in any and all capacities, to sign any or all amendments (including post effective amendments) to this Registration Statement, and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorney-in-fact and agent full power and authority to do and perform each and every act and thing requisite or necessary to be done in and about the premises, as fully to all intents and purposes as such person might or could do in person, hereby ratifying and confirming all that said attorney-in-fact and agent or his or her substitute or substitutes, may lawfully do or cause to be done by virtue thereof.

Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement has been signed by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

Name		Title		Date
/s/ Stephen Cotton		Chief Executive Officer, President and Director		October 24, 2025
Stephen Cotton		(Principal Executive Officer)
/s/ Eric West		Chief Financial Officer		October 24, 2025
Eric West		(Principal Financial and Accounting Officer)
/s/ Vincent L. DiVito		Chairman of the Board of Directors		October 24, 2025
Vincent L. DiVito
/s/ Eric Gangloff		Director		October 24, 2025
Eric Gangloff
/s/ Steve Henderson		Director		October 24, 2025
Steve Henderson

FAQ

What does Aqua Metals (AQMS) register in this S-3?

Up to 1,133,794 shares of common stock for resale, issuable upon exercise of common stock purchase warrants.

What is the warrant exercise price and term for AQMS?

Each warrant has a $11.34 per share exercise price and expires on October 16, 2030.

Will Aqua Metals receive proceeds from this resale?

No. The company receives cash only upon cash exercise of the warrants; potential gross proceeds are approximately $12,857,224 if all are exercised for cash.

Who is the selling stockholder in the AQMS S-3?

The filing lists Hudson Bay Master Fund Ltd. as the selling stockholder with a maximum of 1,133,794 shares offered.

How many AQMS shares were outstanding before the offering?

2,982,762 shares were outstanding as of October 22, 2025.

What is AQMS’s recent stock price reference?

The last reported price was $10.0533 per share on October 23, 2025.

Does the AQMS filing note any major risks?

Yes. It cites stock price volatility and that the auditor’s report includes an explanatory paragraph about substantial doubt regarding going concern.