Form 424B5 - Prospectus [Rule 424(b)(5)]

Share Name	Share Symbol	Market	Type
SEALSQ Corporation	NASDAQ:LAES	NASDAQ	Common Stock

	Price Change	% Change	Share Price	Bid Price	Offer Price	High Price	Low Price	Open Price	Shares Traded	Last Trade
	0.7399	36.81%	2.7499	2.74	2.75	3.00	2.12	2.255	70,364,268	00:59:58

Filed Pursuant to Rule 424(b)(5)

Registration Number 333-283358

PROSPECTUS SUPPLEMENT

(To Prospectus dated November 27, 2024)

13,157,896 Ordinary Shares

SEALSQ Corp

We are offering in a registered direct offering to certain existing investors (the “Investors”) 13,157,896 Ordinary Shares, par value US$0.01 per share (our “Ordinary Shares”), at an offering price of $1.90 per Ordinary Share. The Ordinary Shares offered to the Investors will be issued pursuant to this prospectus supplement, the accompanying base prospectus, and a securities purchase agreement, dated December 17, 2024, by and among us and the Investors (the “Securities Purchase Agreement”).

We engaged Maxim Group LLC to act as our sole placement agent (the “Placement Agent”) in connection with this offering. The Placement Agent is not purchasing the securities offered by us in this offering and is not required to arrange the purchase or sale of any specific number or dollar amount of securities.

Our Ordinary Shares are listed on Nasdaq Capital Market under the symbol “LAES.” The last reported sale price of our Ordinary Shares on the Nasdaq Capital Market on December 17, 2024 was $2.98 per share.

We are an emerging growth company as that term is used in the Jumpstart Our Business Startups Act of 2012 and, as such, are subject to certain reduced public company reporting requirements.

Investing in our Ordinary Shares involves a high degree of risk and uncertainty. See “Risk Factors” beginning on page S-7 of this prospectus supplement, on page 3 of the accompanying base prospectus and in the documents incorporated by reference into this prospectus supplement and accompanying base prospectus concerning factors you should consider before investing in our Ordinary Shares.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus supplement or accompanying prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

	Per Ordinary Share		Total
Public offering price	$	1.90	$	25,000,002.40
Placement agent fees⁽¹⁾	$	0.133	$	1,750,000.17
Proceeds to us, before expenses	$	1.767	$	23,250,002.23

(1)	We have agreed to reimburse the placement agents for certain of their offering-related expenses. See “Plan of Distribution” for additional information regarding placement agent fees and estimated expenses.

The delivery to purchasers of the securities offered and sold in this offering is expected to be made on or about December 19, 2024, subject to satisfaction of certain customary closing conditions.

MAXIM GROUP LLC

Prospectus Supplement dated December 17, 2024.

TABLE OF CONTENTS

PROSPECTUS SUPPLEMENT

ABOUT THIS PROSPECTUS SUPPLEMENT	S-ii
FORWARD-LOOKING STATEMENTS	S-1
PROSPECTUS SUPPLEMENT SUMMARY	S-3
THE OFFERING	S-6
RISK FACTORS	S-7
USE OF PROCEEDS	S-8
CAPITALIZATION	S-9
DESCRIPTION OF SHARE CAPITAL	S-10
CERTAIN TAX CONSIDERATIONS	S-11
PLAN OF DISTRIBUTION	S-13
EXPENSES	S-15
LEGAL MATTERS	S-16
EXPERTS	S-16
ENFORCEMENT OF JUDGMENTS	S-16
WHERE YOU CAN FIND ADDITIONAL INFORMATION	S-16
INCORPORATION BY REFERENCE OF CERTAIN DOCUMENTS	S-16

PROSPECTUS

Page

About this Prospectus	1
About Our Company	2
Risk Factors	3
Forward-Looking Statements	3
Capitalization	6
Use of Proceeds	7
Description of Ordinary Shares	8
Description of Warrants	15
Description of Subscription Rights	17
Description of Units	18
Taxation	19
Plan of Distribution	20
Legal Matters	22
Experts	22
Incorporation of Certain Documents by Reference	22
Where You Can Find More Information	23
Enforceability of Civil Liabilities	23
Expenses	23

S-i

ABOUT THIS PROSPECTUS SUPPLEMENT

This prospectus supplement and the accompanying base prospectus are part of a registration statement on Form F-3 (Registration No. 333-283358) that we filed with the United States Securities and Exchange Commission (“SEC”) using a “shelf” registration process. Under this “shelf” registration process, we may, from time to time, sell or issue any of the combination of securities described in the accompanying base prospectus in one or more offerings with a maximum aggregate offering price of up to US$100,000,000. The accompanying base prospectus provides you with a general description of us and the securities we may offer, some of which do not apply to this offering. Each time we sell securities, we provide a prospectus supplement that contains specific information about the terms of that offering. A prospectus supplement may also add, update, or change information contained in the accompanying base prospectus.

This prospectus supplement relates to the offering of our Ordinary Shares. To the extent there is a conflict between the information contained in this prospectus supplement and the accompanying base prospectus, you should rely on the information in this prospectus supplement. This prospectus supplement, the accompanying base prospectus, and the documents we incorporate by reference herein and therein include important information about us and our Ordinary Shares and other information you should know before investing. You should read both this prospectus supplement and the accompanying base prospectus, together with the additional information described below under the heading “Where You Can Find Additional Information.”

You should rely only on the information contained in or incorporated by reference in this prospectus supplement, the accompanying base prospectus, and any free writing prospectus prepared by or on behalf of us or to which we have referred you. We have not authorized anyone to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. We are not making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted or in which the person making that offer or solicitation is not qualified to do so or to anyone to whom it is unlawful to make an offer or solicitation. You should assume that the information appearing in this prospectus supplement, the accompanying base prospectus, and the documents incorporated by reference herein and therein is accurate only as of the date of those respective documents. Our business, financial condition, results of operations and prospects may have changed since those dates. You should carefully read this entire prospectus supplement and the accompanying base prospectus, including the information included and referred to under “Risk Factors” below, the information incorporated by reference in this prospectus supplement and in the accompanying base prospectus, and the financial statements and the other information incorporated by reference in the accompanying base prospectus, before making an investment decision.

We prepare our financial statements in United States dollars and in accordance with United States generally accepted accounting principles.

All references in this prospectus to “$,” “US$,” “U.S. Dollars” and “dollars” are to United States dollars.

Unless otherwise indicated, references to “SEALSQ,” the “Company,” “we,” “our,” “us” or similar terms refer to the registrant, SEALSQ Corp, and its subsidiaries, except where the context otherwise requires.

This prospectus supplement and the information incorporated by reference herein and therein include trademarks, service marks and trade names owned by us or other companies. Solely for convenience, trademarks referred to in this prospectus, including logos, artwork and other visual displays, may appear without the ® or ™ symbols. We do not intend our use or display of other companies’ trade names or trademarks to imply a relationship with, or endorsement or sponsorship of us by, any other companies. All trademarks, service marks and trade names included or incorporated by reference into this prospectus supplement are the property of their respective owners.

S-ii

FORWARD-LOOKING STATEMENTS

This prospectus supplement and the documents that we have filed with the SEC that are incorporated by reference contain forward-looking statements. These forward-looking statements include information about possible or assumed future results of our operations or our performance. Words such as “expects,” “intends,” “plans,” “believes,” “anticipates,” “estimates,” “projects,” “forecasts” and variations of such words and similar expressions, as they relate to us, WISeKey, our management or third parties, are intended to identify the forward-looking statements. Forward-looking statements include statements regarding our business strategy, financial performance, results of operations, market data, events or developments that SEALSQ expects or anticipates will occur in the future, as well as any other statements which are not historical facts. Although we believe that the expectations reflected in such forward-looking statements are reasonable, no assurance can be given that such expectations will prove to have been correct. These statements involve known and unknown risks and are based upon a number of assumptions and estimates which are inherently subject to significant uncertainties and contingencies, many of which are beyond our control. Actual results may differ materially from those expressed or implied by such forward-looking statements. Forward-looking statements include, but are not limited to, statements we make regarding:

Our anticipated goals, growth strategies and profitability;

Future operating or financial results;

Our planned capital expenditure program for additional production lines to be added to our supply chain;

Our intention to make investments in sales and marketing operations including R&D of new products such as post-quantum cryptography;

Our plans for global customer base expansion;

Our intention to establish a Design Center, OSAT and Personalization project;

Our anticipated pipe growth in 2024 and 2025;

Our belief that the products resulting from our R&D will create additional opportunities for growth;

Our expectation about the development of the markets for SEALSQ, including expanding the role of Metaverse, increase in cyber threats and growth of secure hardware market, growing demand for IoT solutions, increase in cybersecurity spending based on the recent regulations and legislation;

Our intent to invest heavily in the ongoing development of our products and technology;

Our expectation that we will continue to gain several benefits from our parent company, WISeKey, including cash management via a loan agreement, and the financial reporting and legal support via certain service agreements; and

Assumptions underlying or related to any of the foregoing.

The preceding list is not intended to be an exhaustive list of all of our forward-looking statements. The forward-looking statements are based on our beliefs, assumptions and expectations of future performance, taking into account the information currently available to us and are only predictions based upon our current expectations and projections about future events. There are important factors that could cause our actual results, levels of activity, performance or achievements to differ materially from the results, levels of activity, performance or achievements expressed or implied by these forward-looking statements. Those factors include, in addition to those set forth under the heading “Risk Factors” in this prospectus supplement and in the documents incorporated by reference herein, among others, the following:

The inability to realize estimated financial position, results of operations or cash flows;

Our ability to anticipate market needs and opportunities;

Our ability to attract new customers and retain existing customer base;

Our ability to foster innovation and to develop new products and enhancements to our existing products;

The demand for our products or for the goods into which our products are incorporated;

Our expectation that order commitments and non-cancellable orders we received are properly executed;

The sufficiency of our cash and cash equivalents to meet our liquidity needs;

The impact of any supply chain disruption that we may experience;

Our dependency on the timely supply of equipment and materials from our third-party suppliers;

Our ability to protect our intellectual property rights;

Our ability to keep pace with technical advances in cryptography and semiconductor design;

S-1

Our ability to raise funds for investment by cash flow from operating activities, external financing and investment, advance payments from a key customer, and grants and other available subsidies from funding agencies;

Our ability to reduce our cost structure and general and administrative costs;

Our ability to attract and retain qualified employees and key personnel;

Our ability to attract new customers and retain and expand within our existing customer base;

Our ability to foster innovation, to develop new products and enhancements to our existing products;

The future growth of the information technology and cybersecurity industry;

Risks relating to SEALSQ’s ability to implement its growth strategies;

Our ability to successfully form new strategic partnerships with our alliance partners;

Our ability to continue beneficial transactions with material parties, including WISeKey and a limited number of significant customers;

Our ability to prevent security breaches and unauthorized access to confidential customer information;

Our ability to comply with modified or new laws and regulations relating to our industries;

The activities of our competitors and the introduction of competing products by our competitors;

Market demand and semiconductor industry conditions;

Our ability to successfully introduce new technologies and products;

The cyclical nature of the semiconductor industry;

An economic downturn in the semiconductor industry;

Our ability to comply with U.S. and other applicable international laws and regulations;

Changes in our overall tax position as a result of changes in tax laws or tax rates, new or revised legislation, the outcome of tax audits or changes in international tax treaties which may impact our results of operations as well as our ability to accurately estimate tax credits, benefits, deductions and provisions and to realize deferred tax assets;

The potential negative impact on the global economy and capital markets resulting from the conflict in Ukraine or any other geopolitical tensions materially affecting our business, the business of our clients, and the ability of our suppliers to source key components and material;

Fluctuations in the exchange rates between the U.S. dollar and the other major currencies we use for our operations;

Our ability to collect accounts receivable;

Changes in certain commodities used as raw material, which may affect our gross margin; and

How long we will qualify as an emerging growth company or a foreign private issuer.

Given these risks and uncertainties, you should not place undue reliance on forward-looking statements as a prediction of actual results.

WE UNDERTAKE NO OBLIGATION TO PUBLICLY UPDATE OR REVISE ANY FORWARD-LOOKING STATEMENTS CONTAINED IN THIS PROSPECTUS SUPPLEMENT OR THE BASE PROSPECTUS OR THE DOCUMENTS TO WHICH WE REFER YOU IN THIS PROSPECTUS SUPPLEMENT OR THE BASE PROSPECTUS, TO REFLECT ANY CHANGE IN OUR EXPECTATIONS WITH RESPECT TO SUCH STATEMENTS OR ANY CHANGE IN EVENTS, CONDITIONS OR CIRCUMSTANCES ON WHICH ANY STATEMENT IS BASED, EXCEPT AS REQUIRED BY LAW.

S-2

PROSPECTUS SUPPLEMENT SUMMARY

This summary contains basic information about us and our business but does not contain all of the information that is important to your investment decision. Before making an investment decision, you should carefully read this summary together with the more detailed information contained elsewhere in this prospectus supplement and the accompanying base prospectus and the documents incorporated herein and therein by reference, including our Annual Report on Form 20-F for the fiscal year ended December 31, 2023 (the “Annual Report”). Investors should carefully consider the information set forth under the caption “Risk Factors” appearing elsewhere in this prospectus supplement, including those described in documents incorporated by reference herein.

About Our Company

Our mission at SEALSQ is to pioneer the integration of digital trust into the physical world.

SEALSQ stands at the intersection of physical and cyber trust, offering unparalleled assurance in an increasingly interconnected world. At the heart of our offerings is the innovative integration of Cybersecurity, Semiconductors and Post-Quantum Internet of Things (“IoT”.) We are transforming technology, utilizing IoT-generated data, protected and authenticated by our innovative technology, to enable operational enhancements.

SEALSQ is a semiconductor company, specializing in the design of secure microcontrollers, embedding countermeasures capable of resisting state of the art tampering attacks, including the anticipated attacks coming from Quantum computers. SEALSQ is one of the very few actors in the semiconductor industry who has been granted the highest security resistance level (CC EAL5+).

In addition, SEALSQ is a PKI (Public Key Infrastructure) Root Certification Authority, certified by global organizations such as WEBTRUST, GSMA, CSA-MATTER, WI-SUN, each a leader in their respective field: SSL/TLS, telecom, utilities, home automation. SEALSQ plans to introduce to the market in Q4 2024 a Root Certification Authority combining both PKI legacy and PostQuantum (ie Quantum Computer Resistant) cryptographic standards.

SEALSQ is the unique Cybersecurity player combining both Semiconductor and PKI technologies, and capable of delivering to its customers best in class Secure Elements pre-personalized with strong digital identities.

SEALSQ technologies aim to provide connected devices (IoT) with a unique identity, and with cryptographic means used for their authentication, and their secure communications with the platforms that they interface with.

Accordingly, SEALSQ provides its customers with the technology foundation to comply with global regulatory standards (US CybertrustMark, EU Cyber Resistant Act) that the US and the EU will likely start enforcing in 2025.

SEALSQ uses a patented method to digitally certify the authenticity of a physical object of value. The method includes a storage device, a digital certificate of authenticity (encrypted information reflecting at least one characteristic unique to the physical object, checking, whenever required, the validity of the digital certificate of authenticity by use of a network computer), the network computer cooperating with the storage device and a validating or a certifying authority.

With a rich portfolio of 40 patent families, covering over 110 fundamental individual patents, and another 12 patents under review, SEALSQ continues to expand its platform use in various domains. SEALSQ semiconductors secure millions of objects: luxury products, high-end watches, routers, gateways, utilities meters, drones, authentication dongles, storage memory USB sticks, medical devices, connected door-locks, and electronic consumers devices, among others. These semiconductors include Digital Identification technology, such as Keys, Certificates or non-fungible tokens (“NFTs”), that secures, authenticates, and proves ownership of digital and tangible assets.

Our semiconductors, when placed on an object, can securely link the object to NFTs, enabling authentication and tracking of the object. This model is much like an embedded ePassport, and confirm the identity of the object on the Blockchain ledger. This digital identity, used throughout the object’s lifetime, allows the object to become a “Trusted Object” of the Internet, and enables proof of its identity and provision of related verifiable data.

SEALSQ does not provide any technology or services in the management of the NFT creation or the distribution of NFTs. However, SEALSQ’s NFT-related business is to provide its security–related services, Secure Element, to customers in the form of security-enhanced semiconductors. The Secure Element service that SEALSQ provides enables SEALSQ’s customers to create and maintain a secure link between an object and its NFT (issued by a SEALSQ customer that purchases SEALSQ semiconductors) that is stored in a blockchain.

Recent Developments

December 17, 2024 Registered Direct Offering

December 16, 2024 Securities Purchase Agreement

On December 16, 2024, we entered into a securities purchase agreement (the “December 16 Purchase Agreement”) with several institutional investors named therein (the “December 17 Investors”), pursuant to which we agreed to sell and issue 13,157,896 Ordinary Shares to the December 17 Investors at a purchase price of US$1.90 per Ordinary Share, in a registered direct offering (the “December 17 Offering”). The closing of such registered direct offering occurred on December 17, 2024.

The gross proceeds to the Company from the Offering were approximately $25,000,000.00, before deducting the placement agent’s fees and other estimated offering expenses payable by the Company.

The December 17 Offering was made pursuant to the Company’s existing shelf registration statement on Form F-3 (File No. 333- 283358), which was declared effective on November 27, 2024 by the U.S. Securities and Exchange Commission (the “Registration Statement”). A prospectus supplement to the Registration Statement for the December 17 Offering was filed with the Commission on December 17, 2024.

S-3

Pursuant to the December 16 Purchase Agreement, we agreed not to issue, enter into any agreement to issue or announce the issuance or proposed issuance of, any Ordinary Shares of the Company or any securities convertible into or exercisable or exchangeable for Ordinary Shares of the Company or file any registration statement or prospectus, or any amendment or supplement thereto until the earlier of (i) 90 days after the Note Tranche Closing (as defined below) or (ii) March 31, 2025, subject to certain exceptions, without the prior consent of the December 17 Investors.

In addition, we agreed not to effect or enter into an agreement to effect any issuance of Ordinary Shares or any securities convertible into or exercisable or exchangeable for Ordinary Shares involving a Variable Rate Transaction (as defined in the Purchase Agreement) until 180 days after the Note Tranche Closing, subject to certain exceptions.

December 16, 2024 Placement Agency Agreement

On December 16, 2024, we entered into a placement agency agreement with Maxim Group LLC (the “Placement Agent”), pursuant to which we agreed to pay the Placement Agent an aggregate fee equal to 7.0% of the aggregate gross proceeds received by the Company from the sale of the Ordinary Shares in the December 17 Offering. The Company also agreed to reimburse the Placement Agent for up to $40,000 in accountable expenses, including the Placement Agent’s legal counsel’s fees.

December 16, 2024 Registered Direct Offering

December 12, 2024 Securities Purchase Agreement

On December 12, 2024, we entered into a securities purchase agreement (the “December 12 Purchase Agreement”) with several institutional investors named therein (the “December 16 Investors”), pursuant to which we agreed to sell and issue 7,692,308 Ordinary Shares to the December 16 Investors at a purchase price of US$1.30 per Ordinary Share, in a registered direct offering (the “December 16 Offering”). The closing of such registered direct offering occurred on December 16, 2024.

The gross proceeds to the Company from the Offering were approximately $10,000,000.00, before deducting the placement agent’s fees and other estimated offering expenses payable by the Company.

The December 16 Offering was made pursuant to the Company’s existing Registration Statement. A prospectus supplement to the Registration Statement for the December 16 Offering was filed with the Commission on December 16, 2024.

S-4

Pursuant to the December 12 Purchase Agreement, we agreed not to issue, enter into any agreement to issue or announce the issuance or proposed issuance of, any Ordinary Shares of the Company or any securities convertible into or exercisable or exchangeable for Ordinary Shares of the Company or file any registration statement or prospectus, or any amendment or supplement thereto until the earlier of (i) 90 days after the Note Tranche Closing (as defined below) or (ii) March 31, 2025, subject to certain exceptions, without the prior consent of the December 16 Investors.

In addition, we agreed that the terms of the warrants issued by the Company to the December 16 Investors prior to December 12, 2024 (each a “Prior Warrant” and collectively the “Prior Warrants”) will be modified, as of December 16, 2024, as follows: (a) lowering of the exercise price of each Prior Warrant to $2.00 per Ordinary Share, and (b) increase in the quantity of each Prior Warrant such that the aggregate exercise price of the Prior Warrant equals the aggregate exercise price on the issuance date. Further, the Company agreed that if the Company and December 16 Purchasers do not close an additional convertible note tranche in an aggregate principal amount of $10.0 million pursuant to that certain securities purchase agreement, dated July 11, 2023, as amended, by January 16, 2025 (the “Note Tranche Closing”), then the reset above shall be based on the lowering of the exercise price to $1.30 per Ordinary Share (and also a corresponding increase in quantity of warrants as per (b) above).

December 12, 2024 Placement Agency Agreement

On December 12, 2024, we entered into a placement agency agreement with Maxim Group LLC, in its capacity as Placement Agent, pursuant to which we agreed to pay the Placement Agent an aggregate fee equal to 7.0% of the aggregate gross proceeds received by the Company from the sale of the Ordinary Shares in the December 16 Offering. The Company also agreed to reimburse the Placement Agent for up to $40,000 in accountable expenses, including the Placement Agent’s legal counsel’s fees.

Lock-Up Agreements

We, our parent company, WISeKey International Holding AG, and certain of our officers and directors have agreed, subject to certain exceptions, not to offer, issue, sell, contract to sell, encumber, grant any option for the sale of or otherwise dispose of any of our Ordinary Shares or other securities convertible into or exercisable or exchangeable for our Ordinary Shares for a period of 90 days after the December 16 Offering is completed without the prior written consent of the Placement Agent.

SEALCOIN

The responsibility for the development of the decentralized technology project “SEALCOIN” was transferred to our parent company, WISeKey, as of June 27, 2024. While the SEALCOIN project was originally under development by WISeKey and SEALSQ as a collaborative ‘proof of concept’ (with the aim of assessing the practical potential of the concept), the parties concluded that the SEALCOIN platform and tokens would be developed by WISeKey (capitalizing on WISeKey’s cybersecurity expertise), whereas SEALSQ is to focus on the development of the related semiconductor technology hardware and firmware (capitalizing on SEALSQ’s semiconductor and PKI expertise). The future role of SEALSQ in this project is expected to be as a supplier of secure semiconductors to or through SEALCOIN AG, a subsidiary of WISeKey, with SEALCOIN AG as a distributor of those chips to B2B participants in the platform SEALCOIN AG will be developing. Agreements between SEALSQ Corp and SEALCOIN AG are to be entered into reflecting the commercial terms and the Company anticipates that the terms of this contract will be negotiated on an arm’s length basis and that the Company would aim to be the preferred supplier of secure semiconductors to SEALCOIN AG.

Corporate Information

SEALSQ Corp is a BVI business company incorporated and existing under the laws of the British Virgin Islands. Our registered office in the British Virgin Islands is at Craigmuir Chambers, Road Town, Tortola, VG 1110, British Virgin Islands. Our principal executive offices and effective place of management are located at Avenue Louis-Casaï 58, 1216 Cointrin, Switzerland. Our telephone number from the United States is 011 41 22 594 3000. Our website can be accessed at www.SEALSQ.com. The information on or linked to on our website is not a part of this prospectus.

S-5

THE OFFERING

Ordinary Shares Offered By Us	13,157,896 Ordinary Shares

Ordinary Shares to Be Outstanding Immediately Following This Offering	90,209,862 Ordinary Shares

Use of Proceeds	We estimate that our net proceeds from this offering will be approximately $23,100,000, after deducting the placement agent fees and estimated offering expenses payable by us. We intend to use the net proceeds from this offering for fund the deployment of its next-generation post-quantum semiconductor technology and ASIC capabilities in the United States, to support working capital and for general corporate purposes. See “Use of Proceeds” for a more complete description of the intended use of proceeds from this offering.

Risk Factors	See the sections titled “Risk Factors” commencing on page S-7 of this prospectus supplement and in our base prospectus and the Annual Report incorporated by reference herein for a discussion of factors you should consider carefully before deciding to invest in our Ordinary Shares.

Listing	Our Ordinary Shares are listed on the Nasdaq Capital Market under the symbol “LAES.”

Lock-Up	We, and certain of our directors, officers, and affiliates, have agreed, subject to certain exceptions, not to offer, issue, sell, contract to sell, encumber, grant any option for the sale of or otherwise dispose of any of our common stock or other securities convertible into or exercisable or exchangeable for our Ordinary Shares for a period (in the case of the Company) of (i) the earlier of (i) ninety (90) days after the Note Tranche Closing; or (ii) March 31, 2025 or (in the case of our directors and officers), ninety (90) after is the December 16 Offering was completed. See “Plan of Distribution” for more information.

Transfer Agent	Computershare Trust Company, N.A. is the registrar and transfer agent of our Ordinary Shares.

The number of our Ordinary Shares to be outstanding after this offering is based on 77,051,966 of our Ordinary Shares outstanding as of December 17, 2024, and excludes the following:

77 Class F Shares issuable upon the exercise of the Class F Share Options; and

3,687,240 Ordinary Shares issuable upon exercise of the warrants to purchase up to 3,687,240 Ordinary Shares issued to the investors under the Securities Purchase Agreement dated July 11, 2023, entered into with L1 Capital Global Opportunities Master Fund Ltd and Anson Investments Master Fund LP (the “Note Purchase Agreement”), at an exercise price of $2.00 per share (as repriced), which expire on July 11, 2028 (the “First Tranche Warrants”);

4,577,356 Ordinary Shares issuable upon exercise of the warrants to purchase up to 4,577,356 Ordinary Shares issued to the investors under the Amendment dated January 9, 2024 to the Note Purchase Agreement entered into with L1 Capital Global Opportunities Master Fund Ltd and Anson Investments Master Fund LP (the “January Amendment”) at an exercise price of $2.00 per share (as repriced) which expire on January 9, 2029 (the “Second Tranche Warrants”); and

4,227,736 Ordinary Shares issuable upon exercise of the warrants to purchase up to 4,227,736 Ordinary Shares issued to the investors under the Amendment dated March 1, 2024 to the Note Purchase Agreement entered into with L1 Capital Global Opportunities Master Fund Ltd and Anson Investments Master Fund LP (the “March Amendment” and together with the January Amendment, the “Amendments”) at an exercise price of $2.00 per share (as repriced), which expire on March 1, 2029 (the “Third Tranche Warrants” and together with the First Tranche Warrants and Second Tranche Warrants, the “Warrants”).

S-6

RISK FACTORS

An investment in our Ordinary Shares involves a high degree of risk. Before investing in our Ordinary Shares, you should carefully consider the risk factors set forth below and those described under “Risk Factors” in the documents incorporated by reference herein, including in our most recent Annual Report on Form 20-F filed with the SEC, together with the other information included in this prospectus supplement, the base prospectus and incorporated by reference herein from our filings with the SEC. If any of such risks or uncertainties occurs, our business, financial condition, and operating results could be materially and adversely affected. Additional risks and uncertainties not currently known to us or that we currently deem immaterial also may materially and adversely affect our business operations. As a result, the trading price of our Ordinary Shares could decline and you could lose all or a part of your investment.

Risks Related to this Offering

You may experience immediate and substantial dilution in the net tangible book value per share of our Ordinary Shares you purchase in the offering.

The offering price per share in this offering may exceed the pro forma net tangible book value per Ordinary Share outstanding prior to this offering. After giving effect to the sale of 7,692,308 Ordinary Shares at a price of $1.30 per share on December 16, 2024, and after deducting aggregate offering expenses paid by us, our pro forma net tangible book value as of June 30, 2024 would have been approximately $15.2 million or $0.24 per Ordinary Share.

After giving further effect to the sale of 13,157,896 Ordinary Shares at a price of $1.90 per share on December 17, 2024, and after deducting estimated aggregate offering expenses payable by us, our pro forma, as adjusted net tangible book value as of June 30, 2024 would have been approximately $37.4 million, or $0.49 per Ordinary Share.

After giving further effect to the sale of 13,157,896 Ordinary Shares in this offering at a price of $1.90 per share, and after deducting estimated aggregate offering expenses payable by us, our pro forma, as adjusted net tangible book value as of June 30, 2024 would have been approximately $60.5 million, or $0.67 per Ordinary Share.

This represents an immediate increase in as adjusted pro forma net tangible book value to existing stockholders of $0.18 per Ordinary Share and an immediate dilution to purchasers in this offering of $1.23 per Ordinary Share

See the section entitled “Dilution” on page S-12 below for a more detailed illustration of the dilution you may incur if you participate in this offering.

Our management will have broad discretion as to the use of the proceeds from this offering, and may not use the proceeds effectively.

Our management will have broad discretion in the application of the net proceeds from this offering and could spend the proceeds in ways that may not improve our business, financial condition or results of operations or enhance the value of our Ordinary Shares. Our failure to apply these funds effectively could have a material adverse effect on our business and cause the price of our Ordinary Shares to decline.

Resales of our Ordinary Shares in the public market following this offering may cause the trading price to fall.

The resale of a substantial number of Ordinary Shares could depress the trading price of our Ordinary Shares This offering of new Ordinary Shares could result in resales of our Ordinary Shares by our current stockholders concerned about the potential dilution of their holdings. If our stockholders sell substantial amounts of our Ordinary Shares in the public market following the offering contemplated by this prospectus supplement, the trading price of our Ordinary Shares could fall.

Our stock price has been and may continue to be volatile.

The market price of our Ordinary Shares has been, and is likely to continue to be, volatile. The variance in our stock price makes it difficult to forecast the stock price at which an investor may be able to buy or sell Ordinary Shares. The market price for our Ordinary Shares could be subject to fluctuations as a result of factors that are out of our control, such as:

●

actual or anticipated variations in our results of operations;

●

general conditions and trends in the semiconductor industry; and

●

general economic, political and market conditions.

We may, in the future, issue additional Ordinary Shares, which would reduce investors’ percent of ownership and may dilute our share value.

The future issuance of Ordinary Shares may result in substantial dilution in the percentage of our Ordinary Shares held by our then existing stockholders. We may value any Ordinary Shares in the future on an arbitrary basis. The issuance of Ordinary Shares for future services or acquisitions or other corporate actions may have the effect of diluting the value of the shares held by our investors, might have an adverse effect on any trading market for our Ordinary Shares and could impair our ability to raise capital in the future through the sale of equity securities.

An active trading market for our Ordinary Shares may not be sustained.

Although our Ordinary Shares are listed on the Nasdaq Stock Market, LLC, the market for our Ordinary Shares has demonstrated varying levels of trading activity. The current level of trading may not be sustained in the future. The lack of an active market for our Ordinary Shares may impair investors’ ability to sell their Ordinary Shares at the time they wish to sell them or at a price that they consider reasonable, may reduce the fair market value of their Ordinary Shares and may impair our ability to raise capital to continue to fund operations by selling Ordinary Shares and may impair our ability to acquire additional assets by using our Ordinary Shares as consideration.

S-7

USE OF PROCEEDS

We estimate that the net proceeds from the sale of our Ordinary Shares in this offering will be approximately $23,100,000, after deducting placement agent fees and estimated offering expenses payable by us. We intend to use the net proceeds from this offering for working capital and general corporate purposes.

This expected use of the net proceeds from this offering and our existing cash represents our intentions based upon our current plans, financial condition and business conditions. The amount, timing and nature of specific expenditures of net proceeds from this offering will depend on a number of factors, including the timing, scope, progress and results of our development efforts and the timing and progress of any collaboration efforts. As of the date of this prospectus supplement, we cannot specify with certainty all of the particular uses of the proceeds from this offering. Accordingly, we will retain broad discretion over the use of such proceeds.

Pending our use of the net proceeds from this offering, we intend to invest the net proceeds in order to fund the deployment of its next-generation post-quantum semiconductor technology and ASIC capabilities in the United States, to support working capital and for general corporate purposes.

S-8

CAPITALIZATION

The following table sets forth our consolidated capitalization at June 30, 2024

on an actual basis;

on a pro forma basis to give effect, from June 30, 2024 to the date of this prospectus, to (i) the conversion of $10,850,000 under the Convertible Notes set out above into 32,717,132 of our Ordinary Shares , (ii) the issuance on December 16, 2024 of 7,692,308 Ordinary Shares at an offering price of $1.30 per share and (iii) the issuance on December 17, 2024 of 13,157,896 Ordinary Shares at an offering price of $1.90 per share; and

on a pro forma, as adjusted basis, giving effect to the issuance and sale under this prospectus supplement of 13,157,896 Ordinary Shares at an offering price of $1.90 per share.

The information set forth in the following table should be read in conjunction with, and is qualified in its entirety by, reference to our financial statements and the notes thereto incorporated by reference into this prospectus supplement and the accompanying prospectus.

	As of June 30, 2024 (in thousands of U.S. Dollars)
	Actual (unaudited)		Pro Forma (unaudited)		Pro Forma, As Adjusted (unaudited)
Debt⁽¹⁾:
Indebtedness to related parties, noncurrent	—
Bonds, mortgages and other long-term debt	1,734		1,734		1,734
Convertible note payable, noncurrent	9,313		—		—
Indebtedness to related parties, noncurrent	7,478		7,478		7,478
Total debt	18,525		9,212		9,212
Shareholders’ equity:
Capital stock⁽²⁾⁽³⁾
—Ordinary Shares	227		771		902
—Class F Shares	75		75		75
Additional Paid-in Capital	35,616		76,816		99,785
Accumulated other comprehensive income / (loss)	776		776		776
Accumulated deficit	(31,470	)	(31,470	)	(31,470	)
Total equity	5,224		46,968		70,068
Total capitalization	23,749		56,180		79,280

________________________

(1)

All debt is unsecured.

(2)

Under our Articles we are authorized to issue up to 200,000,000 Ordinary Shares, US$0.01 par value per share, of which 22,734,630 are issued and outstanding as of June 30, 2024, and 10,000,000 Class F Shares, US$0.05 par value per share, of which 1,499,700 are issued and outstanding as of June 30, 2024. See “Description of Share Capital” in the accompanying base prospectus.

(3)

Except as otherwise noted, all information in this prospectus reflects and assumes no exercise of outstanding options or warrants.

The above table above excludes:

•

77 Class F Shares issuable upon the exercise of the Class F Share Options

•

Outstanding Warrants to purchase up to 3,687,240 Ordinary Shares issued to the investors under the Note Purchase Agreement at an exercise price of $2.00 per share (as repriced);

•

Outstanding Warrants to purchase up to 4,577,356 Ordinary Shares issued to the investors under the January Amendment to the Note Purchase Agreement at an exercise price of $2.00 per share (as repriced);

•

Outstanding Warrants to purchase up to 4,227,736 Ordinary Shares issued to the investors under the March Amendment to the Note Purchase Agreement at an exercise price of $2.00 per share (as repriced);

S-9

DESCRIPTION OF SHARE CAPITAL

For a description of the rights associated with the Ordinary Shares, see “Description of Share Capital” in the accompanying base prospectus.

S-10

 CERTAIN TAX CONSIDERATIONS

You should carefully read the discussion of the material British Virgin Islands and U.S. federal income tax considerations associated with our operations and the acquisition, ownership and disposition of our Ordinary Shares set forth in Section E, “Taxation,” of Item 10 of our Annual Report, filed with the SEC on March 21, 2024 and incorporated by reference herein.

S-11

DILUTION

If you invest in this offering, your ownership interest will be diluted to the extent of the difference between the public offering price per share and the pro forma as adjusted net tangible book value per share after giving effect to this offering. We calculate net tangible book value per share by dividing the net tangible book value, which is tangible assets less total liabilities, by the number of outstanding Ordinary Shares. Dilution represents the difference between the portion of the amount per share paid by purchasers of Ordinary Shares in this offering and the pro forma as adjusted net tangible book value per share of our Ordinary Shares immediately after giving effect to this offering. Our net tangible book value as of June 30, 2024 was approximately $5.2 million, or $0.09 per Ordinary Share.

After giving effect to the sale of 7,692,308 Ordinary Shares at a price of $1.30 per share on December 16, 2024, and after deducting aggregate offering expenses paid by us, our pro forma net tangible book value as of June 30, 2024 would have been approximately$15.2 million or $0.24 per Ordinary Share.

After giving further effect to the sale of 13,157,896 Ordinary Shares at a price of $1.90 per share on December 17, 2024, and after deducting aggregate offering expenses paid by us, our pro forma net tangible book value as of June 30, 2024 would have been approximately $37.4 million or $0.49 per Ordinary Share.

After giving further effect to the sale of 13,157,896 Ordinary Shares at a price of $1.90 per share, and after deducting estimated aggregate offering expenses payable by us, our pro forma as adjusted net tangible book value as of June 30, 2024 would have been approximately $60.5 million, or $0.67 per Ordinary Share. This represents an immediate increase in as adjusted pro forma net tangible book value to existing stockholders of $0.18 per Ordinary Share and an immediate dilution to purchasers in this offering of $1.23 per Ordinary Share.

The following table illustrates this per share dilution:

Assumed offering price per share			$	1.90
Net tangible book value per share as of June 30, 2024	$	0.09
Increase per share attributable to the sale on December 16, 2024	$	0.15
Pro forma net tangible book value as of June 30, 2024	$	0.24
Increase per share attributable to the sale on December 17, 2024	$	0.25
Pro forma net tangible book value as of June 30 2024	$	0.49
Increase per share attributable to this offering	$	0.18
Pro Forma as adjusted net tangible book value per share as of June 30, 2024, after giving effect to this offering			$	0.67
Dilution per share to new investors purchasing shares in this offering			$	1.23

The above discussion and table is based on 56,201,762 shares of Ordinary Shares outstanding, as of December 13, 2024, and excludes:

77 Class F Shares issuable upon the exercise of the Class F Share Options; and

3,687,240 Ordinary Shares issuable upon exercise of the Warrants to purchase up to 3,687,240 Ordinary Shares issued to the investors under the Note Purchase Agreement at an exercise price of $2.00 per share (as repriced) which expire on July 11, 2028;

4,577,356 Ordinary Shares issuable upon exercise of the Warrants to purchase up to 4,577,356 Ordinary Shares issued to the investors under the Amendment dated January 9, 2024 to the Note Purchase Agreement at an exercise price of $2.00 per share (as repriced), which expire on January 9, 2029; and

4,227,736 Ordinary Shares issuable upon exercise of the Warrants to purchase up to 4,227,736 Ordinary Shares issued to the investors under the Amendment dated March 1, 2024 to the Note Purchase Agreement at an exercise price of $2.00 per share (as repriced), which expire on March 1, 2029.

Except as otherwise indicated, all information in this prospectus supplement assumes no exercise of the outstanding options or warrants described above. To the extent that any of these outstanding warrants or options are exercised at prices per Ordinary Share below the public offering price per share in this offering or we issue additional Ordinary Shares under our equity incentive plans at prices below the public offering price per Ordinary Share in this offering, you may experience further dilution. In addition, to the extent that we raise additional capital by issuing equity or convertible debt securities, your ownership will be further diluted.

S-12

PLAN OF DISTRIBUTION

Maxim Group, LLC, who we refer to as “Maxim” or the placement agent has agreed to act as the exclusive placement agent in connection with this offering subject to the terms and conditions of the placement agency agreement, dated as of December 17, 2024. The placement agent has not purchased or sold any of the shares of our Ordinary Shares offered by this prospectus supplement, nor is it required to arrange the purchase or sale of any specific number or dollar amount of our Ordinary Shares, but have agreed to use its reasonable best efforts to arrange for the sale of all of the Ordinary Shares offered hereby. We entered into a securities purchase agreement, dated as of December 17, 2024, directly with the investors in connection with this offering and we will only sell to the investors who have entered into the securities purchase agreement with us.

We expect to deliver the 13,157,896 Ordinary Shares sold in this offering and being offered pursuant to this prospectus supplement on or about December 19, 2024, subject to customary closing conditions.

Placement Agent Fees, Commissions and Expenses

We have agreed to pay the placement agent a placement agent fee equal to 7% of the aggregate purchase price of the shares of our Ordinary Shares sold in this offering. We have also agreed to reimburse the Placement Agent up to $40,000 for the reasonable and accounted fees and expenses of legal counsel. The following table shows the per share and total cash placement agent’s fees we will pay to the placement agent in connection with the sale of the shares of our Ordinary Shares offered pursuant to this prospectus supplement and the accompanying prospectus.

	Per Share		Total
Offering price	$	1.90	$	25,000,002.40
Placement agent’s fees	$	0.133	$	1,750,000.17
Proceeds, before expenses, to us	$	1.767	$	23,250,002.23

Regulation M

The placement agent may be deemed to be an underwriter within the meaning of Section 2(a)(11) of the Securities Act of 1933, as amended (the “Securities Act”), and any commissions received by it and any profit realized on the resale of the shares sold by it while acting as principal might be deemed to be underwriting discounts or commissions under the Securities Act. As underwriter, the placement agent would be required to comply with the requirements of the Securities Act and the Securities Exchange Act of 1934, as amended (the “Exchange Act”), including, without limitation, Rule 415(a)(4) under the Securities Act and Rule 10b-5 and Regulation M under the Exchange Act. These rules and regulations may limit the timing of purchases and sales of shares by the placement agent acting as principal. Under these rules and regulations, the placement agent:

·		may not engage in any stabilization activity in connection with our securities; and

·		may not bid for or purchase any of our securities or attempt to induce any person to purchase any of our securities, other than as permitted under the Exchange Act, until it has completed its participation in the distribution.

Determination of Offering Price

The actual offering price of the securities we are offering were negotiated between us, the placement agent and the investors in the offering based on the trading price of our Ordinary Shares prior to the offering, among other things. Other factors considered in determining the public offering price of the securities we are offering, included our history and prospects, the stage of development of our business, our business plans for the future and the extent to which they have been implemented, an assessment of our management, the general conditions of the securities markets at the time of the offering and such other factors as were deemed relevant.

Indemnification

We have agreed to indemnify the placement agent and certain specified other persons against certain liabilities, including liabilities under the Securities Act and the Exchange Act, and to contribute to payments the placement agent and such other persons may be required to make in respect thereof.

Subsequent Equity Sales

Pursuant to the terms of the securities purchase agreement, from the date hereof until the earlier of (i) the earlier of (i) ninety (90) days after the Note Tranche Closing; or (ii) March 31, 2025 we may not issue, enter into any agreement to issue or announce the issuance or proposed issuance of any Ordinary Shares or Ordinary Share equivalents, or, file any registration statement or any amendment or supplement thereto, in each case, subject to certain exceptions, without the prior consent of the Investors. In addition, from the date of this prospectus supplement until 180 days after the closing date of this offering, we are prohibited, subject to certain exceptions, from effecting or entering into an agreement to effect any issuance of Ordinary Shares or Ordinary Share equivalents involving a variable rate transaction (as defined in the securities purchase agreement).

S-13

Electronic Distribution

This prospectus supplement and the accompanying prospectus may be made available in electronic format on websites or through other online services maintained by the placement agent or by an affiliate. Other than this prospectus supplement and the accompanying prospectus, the information on the placement agent’s website and any information contained in any other website maintained by the placement agent is not part of this prospectus supplement and the accompanying prospectus or the registration statement of which this prospectus supplement and the accompanying prospectus form a part, has not been approved and/or endorsed by us or the placement agent, and should not be relied upon by investors.

Other

The foregoing does not purport to be a complete statement of the terms and conditions of the placement agency agreement and the form of the securities purchase agreement. A copy of the form of the securities purchase agreement with the purchasers will be included as an exhibit to our Current Report on Form 6-K to be filed with the SEC and incorporated by reference into the registration statement of which this prospectus supplement and the accompanying prospectus form a part. See “Incorporation of Certain Documents by Reference” and “Where You Can Find More Information.”

Certain Relationships

The placement agent and its affiliates may provide from time to time in the future certain commercial banking, financial advisory, investment banking and other services for us in the ordinary course of their business, for which they may receive customary fees and commissions. In addition, from time to time, the placement agent and its affiliates may effect transactions for their own account or the account of customers, and hold on behalf of themselves or their customers, long or short positions in our debt or equity securities or loans, and may do so in the future. However, except as disclosed in this prospectus supplement, we have no present arrangements with the placement agent for any further services.

Below is a description of certain recent investment banking and financial advisory services that Maxim has provided to us in the ordinary course of business, for which Maxim received customary fees, commissions and other compensation.

Convertible Note and Warrant Private Placements

Maxim served as the sole placement agent for us in connection with the private placements of notes and warrants to certain investors on July 11, 2023, January 9, 2024 and March 1, 2024, respectively. Under the terms of this arrangement, SEALSQ has paid a total of $1,515,000 to Maxim.

December 16, 2024 Registered Direct Offering

Maxim served as the sole placement agent for us in connection with the December 16 Offering. Under the terms of this arrangement, SEALSQ paid a total of $700,000.03 to Maxim.

December 17, 2024 Registered Direct Offering

Maxim served as the sole placement agent for us in connection with the December 17 Offering. Under the terms of this arrangement, SEALSQ paid a total of $1,750,000.17 to Maxim.

S-14

EXPENSES

The following is an estimate of the expenses (all of which are to be paid by us) that we may incur in connection with the securities being registered hereby. Each prospectus supplement describing an offering of securities will reflect the estimated expenses related to the offering of securities under that prospectus supplement.

SEC registration fee*	$	--
FINRA filing fee**	$	--
Legal fees and expenses***	$	110,000
Accounting fees and expenses*	$	-
Total	$	110,000

*$15,310 previously paid

**$15,500 previously paid

***Estimated

S-15

LEGAL MATTERS

Certain legal matters with respect to British Virgin Islands law in connection with this offering are being passed upon for us by Harney Westwood & Riegels LP. Certain matters of U.S. federal and New York law are being passed upon for us by Patterson Belknap Webb & Tyler LLP, New York, New York. Loeb & Loeb LLP, New York, New York has acted as counsel to the Placement Agent.

EXPERTS

The financial statements incorporated in this prospectus supplement by reference to the Annual Report on Form 20-F for the year ended December 31, 2023 have been so incorporated in reliance on the report of BDO Ltd., an independent public accounting firm, given on the authority of said firm as experts in auditing and accounting. The financial statements incorporated in this prospectus supplement by reference to the Annual Report on Form 20-F for the year ended December 31, 2022 have been so incorporated in reliance on the report of BDO Rhône Alpes, an independent public accounting firm, given on the authority of said firm as experts in auditing and accounting.

ENFORCEABILITY OF CIVIL LIABILITIES

We are incorporated under the laws of the British Virgin Islands and our principal executive offices are located outside the United States. Most of our directors and officers and those of our subsidiaries are residents of countries other than the United States. Substantially all of our and our subsidiaries’ assets and a substantial portion of the assets of our directors and officers are located outside the United States. As a result, it may be difficult or impossible for United States investors to effect service of process within the United States upon us, our directors or officers or our subsidiaries, or to realize against us or them judgments obtained in United States courts, including judgments predicated upon the civil liability provisions of the securities laws of the United States or any state in the United States.

Furthermore, there is substantial doubt that courts in jurisdictions outside the U.S. (i) would enforce judgments of U.S. courts obtained in actions against us or our directors or officers based upon the civil liability provisions of applicable U.S. federal and state securities laws or (ii) would enforce, in original actions, liabilities against us or our directors or officers based on those laws.

WHERE YOU CAN FIND MORE INFORMATION

We have filed with the SEC a registration statement on Form F-3 under the Securities Act, relating to this offering of securities. This prospectus supplement does not contain all of the information contained in the registration statement. The rules and regulations of the SEC allow us to omit certain information from this prospectus supplement that is included in the registration statement. Statements made in this prospectus supplement concerning the contents of any contract, agreement or other document are summaries of all material information about the documents summarized, but are not complete descriptions of all terms of these documents. If we filed any of these documents as an exhibit to the registration statement, you may read the document itself for a complete description of its terms.

We are subject to the informational requirements of the Exchange Act applicable to foreign private issuers. In accordance with the Exchange Act, we file reports, including annual reports on Form 20-F containing financial statements audited by an independent accounting firm. We also furnish to the SEC, under cover of Reports of Foreign Private Issuer on Form 6-K, material information required to be made public by us or filed by us with and made public by any stock exchange or distributed by us to our shareholders. Such reports and other information filed with the SEC are available to the public over the internet at the SEC’s website at http://www.sec.gov. We also generally make available on our own website (www.sealsq.com) our quarterly and year-end financial statements as well as other information.

As a foreign private issuer, we are exempt from the rules under the Exchange Act prescribing the furnishing and content of proxy statements to shareholders, and our officers, directors and principal shareholders are exempt from the “short-swing profits” reporting and liability provisions contained in Section 16 of the Exchange Act and related Exchange Act rules. In addition, we are not required under the Exchange Act to file periodic reports and financial statements as frequently or as promptly as U.S. companies whose securities are registered under the Exchange Act.

We maintain a corporate website at www.sealsq.com. Information contained on, or that can be accessed through, our website does not constitute a part of this prospectus supplement. We have included our website address in this prospectus supplement solely as an inactive textual reference.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

The SEC allows us to incorporate by reference our publicly filed reports into this prospectus supplement, which means that information included in those reports is considered part of this prospectus supplement. Because we are incorporating by reference future filings with the SEC, this prospectus supplement is continually updated and those future filings may modify or supersede some of the information included or incorporated by reference in this prospectus supplement. This means that you must look at all of the SEC filings that we incorporate by reference to determine if any of the statements in this prospectus supplement or in any document previously incorporated by reference have been modified or superseded. This prospectus supplement incorporates by reference the documents listed below and any future filings we make with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934 (the “Exchange Act”) (in each case, other than those documents or the portions of those documents furnished, rather than filed), and, to the extent designated therein, reports on Form 6-K, until the offering of the securities under the registration statement of which this prospectus forms a part is terminated or completed:

our Annual Report on Form 20-F for the year ended December 31, 2023, filed with the SEC on March 21, 2024;

our Reports on Form 6-K furnished by us to the SEC on March 22, 2024, July 1, 2024, July 12, 2024, July 25, 2024, August 2, 2024, September 25, 2024, November 19, 2024, December 16, 2024, and December 17, 2024; and

the description of our Ordinary Shares contained in our Registration Statement on Form 8-A filed with the SEC on May 18, 2023, as amended by Exhibit 2.4 to our Annual Report on Form 20-F for the year ended December 31, 2023, filed with the SEC on March 21, 2024, as further amended and supplemented by the description of our Securities contained in this prospectus under “Description of Ordinary Shares,” including any subsequent amendment or any report filed for the purpose of updating such description.

S-16

The SEC maintains an Internet site at http://www.sec.gov that contains reports, proxy and information statements, and other information regarding issuers like us that file electronically with the SEC.

We will also incorporate by reference all subsequent Annual Reports on Form 20-F that we file with the SEC. In addition, we will incorporate by reference certain future materials furnished to the SEC on Form 6-K after the date of the initial registration statement, but only to the extent specifically indicated in those submissions or in a future prospectus supplement. Each subsequently filed Annual Report should be deemed to supersede entirely each earlier filed Annual Report and the materials furnished on an earlier Form 6-K and, unless explicitly stated otherwise, such earlier reports should not be deemed to be part of this prospectus supplement and you should not rely upon statements made in those earlier periodic reports. In all cases, you should rely on the later information over different information in this prospectus supplement.

We will furnish without charge to you, on written or oral request, a copy of any or all of the above documents, other than exhibits to such documents which are not specifically incorporated by reference therein. You should direct any requests for documents to:

SEALSQ Corp

Avenue Louis-Casaï 58

1216 Cointrin Switzerland

Tel: 011-41-22-594-3000

Fax: 011-41-22-594-3001

The information relating to us contained in this prospectus supplement is not comprehensive and should be read together with the information contained in the incorporated documents. Descriptions contained in the incorporated documents as to the contents of any contract or other document may not contain all of the information which is of interest to you. You should refer to the copy of such contract or other document filed as an exhibit to our filings.

S-17

PROSPECTUS

$100,000,000

Ordinary Shares

Warrants

Subscription Rights

Units

SEALSQ Corp

_________________

We may offer, from time to time, in one or more offerings, Ordinary Shares, warrants to purchase Ordinary Shares, subscription rights or units, which we collectively refer to as the “securities”. The aggregate initial offering price of the securities that we may offer and sell under this prospectus will not exceed $100,000,000.

Each time we sell securities pursuant to this prospectus, we will provide in a supplement to this prospectus the price and any other material terms of any such offering. Any prospectus supplement may also add, update or change information contained in this prospectus. You should read this prospectus and any applicable prospectus supplement, as well as the documents incorporated by reference or deemed incorporated by reference into this prospectus, carefully before you invest in any securities. This prospectus may not be used to offer or sell securities unless accompanied by a prospectus supplement.

We may, from time to time, offer to sell the securities, through public or private transactions, directly or through underwriters, agents or dealers, on or off the Nasdaq Capital Market, or Nasdaq, at prevailing market prices or at privately negotiated prices. If any underwriters, agents or dealers are involved in the sale of any of these securities, the applicable prospectus supplement will set forth the names of the underwriter, agent or dealer, and any applicable fees, commissions or discounts.

Our Ordinary Shares are listed on the Nasdaq Capital Market under the ticker symbol “LAES.” The last reported sale price of our Ordinary Shares on the Nasdaq Capital Market on November 18, 2024 was $0.5080 per share.

On November 18, 2024, the aggregate market value worldwide of our outstanding common equity held by non-affiliates, our “public float,” was approximately $12.7 million, based on 25,077,150 Ordinary Shares outstanding held by non-affiliates and a per share price of $0.5080 based on the closing sale price of the Ordinary Shares on Nasdaq on November 18, 2024. As of the date hereof, we have not sold any securities pursuant to General Instruction I.B.5 of Form F-3 during the prior 12 calendar month period that ends on and includes the date hereof. After the date of this prospectus, we will not sell in primary offerings under General Instruction I.B.5 of Form F-3 securities having an aggregate market value, when added to the aggregate market value of securities sold by us in primary offerings under General Instruction I.B.5 of Form F-3 during the 12 calendar months immediately prior to and including the date of sale, of more than one-third of our public float.

Investing in our securities involves a high degree of risk. Please carefully consider the risks discussed in this prospectus under “Risk Factors” beginning on page 3 and the “Risk Factors” in “Item 3.D: Key Information—Risk Factors” of our most recent Annual Report on Form 20-F incorporated by reference in this prospectus and in any applicable prospectus supplement for a discussion of the factors you should consider carefully before deciding to purchase these securities.

Neither the Securities and Exchange Commission, nor any other regulatory body has approved or disapproved of these securities or determined if this prospectus supplement or the accompanying prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

Prospectus dated November 27, 2024.

ABOUT THIS PROSPECTUS

This prospectus is part of a Registration Statement on Form F-3 that we filed with the Securities and Exchange Commission, or the SEC, utilizing a “shelf” registration process. Under this shelf registration process, we may sell our securities described in this prospectus in one or more offerings up to a total dollar amount of $100,000,000. Furthermore, so long as the aggregate market value worldwide of our public float is less than $75 million, the aggregate market value of securities sold by us pursuant to this shelf registration statement during the period of 12 calendar months immediately prior to, and including, the sale, shall be no more than one- third of the public float. This prospectus does not contain all of the information set forth in the registration statement, certain parts of which are omitted in accordance with the rules and regulations of the SEC. Accordingly, you should refer to the registration statement and its exhibits for further information about us and our securities. Copies of the registration statement and its exhibits are on file with the SEC. Statements contained in this prospectus concerning the documents we have filed with the SEC are not intended to be comprehensive, and in each instance we refer you to a copy of the actual document filed as an exhibit to the registration statement or otherwise filed with the SEC.

Each time we offer our securities pursuant to this registration statement, we will provide you with a prospectus supplement that will describe the specific amounts, prices and terms of the securities we offer. The prospectus supplement may also add, update or change information contained in this prospectus. This prospectus, together with applicable prospectus supplements and the documents incorporated by reference in this prospectus and any prospectus supplements, includes all material information relating to this offering. Please read carefully both this prospectus and any prospectus supplement together with additional information described below under “Where You Can Find More Information” and “Incorporation of Certain Documents by Reference.”

This prospectus does not contain all of the information provided in the registration statement that we filed with the Commission. For further information about us or our securities, you should refer to that registration statement, which you can obtain from the Commission as described below under “Where You Can Find More Information” and “Incorporation of Certain Documents by Reference.”

You should rely only on the information incorporated by reference or provided in this prospectus or any prospectus supplement. “Incorporated by reference” means that we can disclose important information to you by referring you to another document filed separately with the SEC. We have not authorized anyone to provide you with different information. We are offering to sell, and seeking offers to buy, our securities only in jurisdictions where offers and sales are permitted. We are not making, nor will we make, an offer to sell securities in any jurisdiction where the offer or sale is not permitted. You should assume that the information appearing in this prospectus and any supplement to this prospectus is current only as of the dates on their respective covers. Our business, financial condition, results of operations and prospects may have changed since that date.

We prepare our financial statements in United States dollars and in accordance with United States generally accepted accounting principles.

Certain figures included in this prospectus have been subject to rounding adjustments. Accordingly, figures shown as totals in certain tables may not be an arithmetic aggregation of the figures that precede them.

In this prospectus, “we,” “us,” “our,” the “Company” and “SEALSQ” refers to SEALSQ Corp. Any reference to “WISeKey” is to WISeKey International Holding AG and its subsidiaries, except where the context otherwise requires.

All references in this prospectus to “$,” “U.S. Dollars” and “dollars” are to United States dollars.

This prospectus and the information incorporated by reference herein and therein include trademarks, service marks and trade names owned by us or other companies. Solely for convenience, trademarks referred to in this prospectus, including logos, artwork and other visual displays, may appear without the ® or ™ symbols. We do not intend our use or display of other companies’ trade names or trademarks to imply a relationship with, or endorsement or sponsorship of us by, any other companies. All trademarks, service marks and trade names included or incorporated by reference into this prospectus or an accompanying prospectus supplement are the property of their respective owners.

ABOUT OUR COMPANY

This summary highlights selected information contained elsewhere in this prospectus that we consider important. This summary does not contain all of the information you should consider before investing in our securities. You should read this summary together with the entire prospectus, including the risks related to our business, our industry and investing in our securities that we describe under “Risk Factors,” and our consolidated financial statements and the related notes incorporated by reference in this prospectus before making an investment in our securities.

Our mission at SEALSQ is to pioneer the integration of digital trust into the physical world.

In addition, SEALSQ is a PKI (Public Key Infrastructure) Root Certification Authority, certified by global organizations such as WEBTRUST, GSMA, CSA-MATTER, WI-SUN, each leader in their respective field: SSL/TLS, telecom, utilities, home automation. SEALSQ plans to introduce to the market in Q4 2024 a Root Certification Authority combining both PKI legacy and PostQuantum (ie Quantum Computer Resistant) cryptographic standards.

Recent Developments

Corporate Information

RISK FACTORS

Investing in our securities involves significant risks. Before making an investment decision, you should carefully consider the risks described under “Risk Factors” in the applicable prospectus supplement and under “Item 3.D: Key Information—Risk Factors” in our most recent Annual Report on Form 20-F, or any updates in our Reports on Form 6-K, together with all of the other information appearing in this prospectus or incorporated by reference into this prospectus and any applicable prospectus supplement, in light of your particular investment objectives and financial circumstances.

The risks so described are not the only risks facing us. Additional risks not presently known to us or that we currently deem immaterial may also impair our business operations. Our business, financial condition and results of operations could be materially adversely affected by any of these risks. The trading price of our securities could decline due to any of these risks, and you may lose all or part of your investment. The discussion of risks includes or refers to forward-looking statements; you should read the explanation of the qualifications and limitations on such forward-looking statements discussed elsewhere in this prospectus.

Sales of our Ordinary Shares, or the perception of such sales, including by the investors in our recent convertible note and warrant financings pursuant to the Registration Statement on Form F-1 filed on April 15, 2024 (File No.: 333-278685) in the public market or otherwise could cause the market price for our Ordinary Shares to decline.

The sale of our Ordinary Shares in the public market or otherwise could harm the prevailing market price of our Ordinary Shares. These sales, or the possibility that these sales may occur, also might make it more difficult for us to sell equity securities in the future at a time and at a price that we deem appropriate (which ability to sell equity securities is also subject to restrictions under the terms of the note and warrant financing agreements). Resales of our Ordinary Shares may cause the market price of our securities to drop significantly, regardless of the performance of our business.

Following the conversion of the notes and/or the exercise of the warrants issued in these financings, there are no limitations on the investors’ ability to sell the Ordinary Shares received by the investors. As such, sales of a substantial number of Ordinary Shares in the public market could occur at any time following such conversion or exercise. These sales, or the perception in the market that the holders of a large number of shares intend to sell shares, could reduce the market price of our Ordinary Shares.

Given the substantial number of Ordinary Shares that were registered for potential resale by the investors pursuant to the Registration Statement on Form F-1 filed on April 15, 2024 (File No.: 333-278685), the sale of Ordinary Shares by the investors, or the perception in the market that the shareholders of a large number of Ordinary Shares intend to sell Ordinary Shares, could increase the volatility of the market price of our Ordinary Shares or result in a significant decline in the public trading price of our Ordinary Shares.

Our failure to meet Nasdaq’s continued listing requirements could result in a delisting of our Ordinary Shares.

On August 1, 2024, we received written notification from the NASDAQ Stock Market, indicating that because the closing bid price of our Ordinary Shares for 30 consecutive business days, from June 18, 2024 to July 31, 2024, was below the minimum $1.00 per share bid price requirement for continued listing on the Nasdaq Capital Market, we were not in compliance with Nasdaq Listing Rule 5550(a)(2). Pursuant to Nasdaq Listing Rule 5810(c)(3)(A), the applicable grace period to regain compliance is 180 days, or until January 28, 2025. If we fail to maintain compliance with Nasdaq’s continued listing standards, whether due to the minimum bid price deficiency or any other future deficiency, are delisted from Nasdaq and our Ordinary Shares are not subsequently listed on another national securities exchange, we will be unable to meet certain transaction requirements that would effectively prevent us from offering and selling additional Ordinary Shares under this registration statement, and could be in breach of covenants in various contracts.

FORWARD-LOOKING STATEMENTS

This prospectus contains forward-looking statements. These forward-looking statements include information about possible or assumed future results of our operations or our performance. Words such as “expects,” “intends,” “plans,” “believes,” “anticipates,” “estimates,” “projects,” “forecasts” and variations of such words and similar expressions, as they relate to us, WISeKey, our management or third parties, are intended to identify the forward-looking statements. Forward-looking statements include statements regarding our business strategy, financial performance, results of operations, market data, events or developments that SEALSQ expects or anticipates will occur in the future, as well as any other statements which are not historical facts. Although we believe that the expectations reflected in such forward-looking statements are reasonable, no assurance can be given that such expectations will prove to have been correct. These statements involve known and unknown risks and are based upon a number of assumptions and estimates which are inherently subject to significant uncertainties and contingencies, many of which are beyond our control. Actual results may differ materially from those expressed or implied by such forward-looking statements. Forward-looking statements include, but are not limited to, statements we make regarding:

Our anticipated goals, growth strategies and profitability;

Future operating or financial results;

Our planned capital expenditure program for additional production lines to be added to our supply chain;

Our intention to make investments in sales and marketing operations including R&D of new products such as post-quantum cryptography;

Our plans for global customer base expansion;

Our intention to establish a Design Center, OSAT and Personalization project;

Our anticipated pipe growth in 2024 and 2025;

Our belief that the products resulting from our R&D will create additional opportunities for growth;

Our intent to invest heavily in the ongoing development of our products and technology;

Assumptions underlying or related to any of the foregoing.

The preceding list is not intended to be an exhaustive list of all of our forward-looking statements. The forward-looking statements are based on our beliefs, assumptions and expectations of future performance, taking into account the information currently available to us and are only predictions based upon our current expectations and projections about future events. There are important factors that could cause our actual results, levels of activity, performance or achievements to differ materially from the results, levels of activity, performance or achievements expressed or implied by these forward-looking statements. Those factors include, in addition to those set forth under the heading “Risk Factors” in this prospectus and in the documents incorporated by reference herein and under a similar heading in any applicable prospectus supplement., among others, the following: