Quantisimo Corp., the Pure-Play Sovereign Quantum Vertical Platform “Root to Qubit” Formed by WISeQey and SEALSQ, Signs Definitive Business Combination Agreement with[...]

Quantisimo Corp., the Pure-Play Sovereign Quantum Vertical Platform "Root to Qubit" Formed by WISeQey and SEALSQ, Signs Definitive Business Combination Agreement with GigCapital8 Corp. to Become a Nasdaq-Listed Public Company

Geneva, Switzerland/Palo Alto, CA - October 9, 2026 - Ad hoc announcement pursuant to Art. 53 LR Quantisimo Corp. ("Quantisimo"), a special purpose vehicle established by WISeQey (Nasdaq/SIX: WQEY)

and SEALSQ (Nasdaq: LAES), today announced that it has entered into a definitive Agreement and Plan of Merger. The proposed business combination (the "Business Combination" or the "transaction") would result in Quantisimo and GigCapital8 Corp. ("GigCapital8"), A Private to Public Equity (PPE) company also known as a special purpose acquisition company (NASDAQ: GIW) becoming wholly owned subsidiaries of a newly formed British Virgin Islands holding company, Quantisimo Holding Corp. ("PubCo"), whose ordinary shares are expected to be listed on the Nasdaq Capital Market under the symbol "QSMO."

A Pure-Play Sovereign Quantum Vertical Platform: "Root to Qubit"

Quantisimo is a special purpose technology vehicle established by WISeQey and its subsidiary SEALSQ to build a pure-play sovereign quantum vertical platform, "Root to Qubit." Prior to closing, WISeQey and SEALSQ will contribute to Quantisimo their interests in the operating businesses of Miraex SA (Switzerland), SEALCOIN AG (Switzerland), WeCan Group SA (Switzerland) and WISeSat.Space.

A pure-play quantum company is a business whose primary operations, revenues, and investment profile focus exclusively on quantum computing, networking, sensing, or cybersecurity, rather than treating quantum as a side project within a larger conglomerate.

Quantisimo is being developed toward this model, with a strategy to integrate complementary capabilities across the quantum value chain. "Root to Qubit" describes its ambition to connect cryptographic roots of trust, secure identity and post-quantum protection with quantum networking, photonic technologies, quantum sensing, quantum computing and the infrastructure connecting these capabilities.

Its sovereign approach emphasizes trusted control of critical technologies, intellectual property, security architectures and deployment choices, enabling customers and partners to develop quantum infrastructure aligned with their security and sovereignty requirements.

Quantisimo is designed to give investors concentrated exposure to this sovereign quantum platform through proprietary technologies, strategic investments, intellectual property and selected assets from the SEALQuantum Sovereign Vertical Stack. Its strategy is to develop, acquire and commercialize complementary capabilities across the quantum value chain, progressively connecting the security foundations of digital infrastructure with the physical systems that generate, transmit and process quantum information.

Within this strategy, post-quantum cybersecurity, trusted digital transactions and secure satellite connectivity serve as enabling layers and applications of the sovereign quantum platform. Quantisimo's pure-play positioning reflects its strategic focus on building and commercializing this integrated quantum ecosystem.

"Today marks a defining milestone in our ambition to build Quantisimo as a pure-play sovereign quantum vertical platform, from Root to Qubit," said Carlos Moreira, Chief Executive Officer of WISeQey, SEALSQ and WISeSat.Space. "Our vision is to connect the foundations of digital trust with quantum networking, quantum computing and secure terrestrial and space infrastructure. By bringing together complementary businesses, intellectual property and strategic quantum investments, we aim to give governments, enterprises and infrastructure operators greater control over the technologies that will underpin the quantum economy. Partnering with GigCapital8 and Dr. Avi Katz, whose Mentor-Investor™ PPETM approach has guided numerous technology companies to the public markets, provides a path to the U.S. public markets to support this strategy. WISeQey and SEALSQ are expected to remain majority shareholders following closing, reflecting our long-term commitment to developing the platform and creating lasting value for our shareholders, partners and customers."

Transaction Summary

Under the Agreement and Plan of Merger (the "Business Combination Agreement"), a subsidiary of PubCo will merge with and into GigCapital8, with GigCapital8 surviving as a wholly owned subsidiary of PubCo, and immediately thereafter a second subsidiary of PubCo will merge with and into Quantisimo, with Quantisimo surviving as a wholly owned subsidiary of PubCo. Each GigCapital8 Class A ordinary share will be exchanged for one PubCo ordinary share, each five GigCapital8 rights will convert into one PubCo ordinary share, and the shareholders of Quantisimo will receive an aggregate of 66,610,000 PubCo shares, consisting of ordinary shares and Class F shares, with all Class F shares (GigCapital8's sponsor will also receive Class F shares for a portion of its GigCapital8 ordinary shares) carrying, in the aggregate, 49.999999% of PubCo's total voting power.

Closing is conditioned on, among other things, available cash of at least $15 million, comprising cash from GigCapital8's trust account after redemptions and any PIPE investment, together with a cash contribution from SEALSQ, which will receive additional PubCo ordinary shares at $10.00 per share for its contribution. Any PIPE investment is expected to be priced at not less than $10.00 per share. WISeQey, SEALSQ, GigCapital8's sponsor and GigCapital8's directors and officers will enter into customary lock-up agreements for six months following closing, and GigCapital8's sponsor has agreed to vote its shares in favor of the transaction and not to redeem them.

The boards of directors of GigCapital8, Quantisimo, WISeQey and SEALSQ , and PubCo have approved the Business Combination, and the board of directors of GigCapital8 has unanimously recommended that GigCapital8's shareholders approve it. The Business Combination is expected to be completed in the first quarter of 2027, subject to customary closing conditions, including the approval of GigCapital8's shareholders, the effectiveness of the Registration Statement referenced below and the approval of PubCo's listing on Nasdaq.

Additional information about the proposed Business Combination, including a copy of the Business Combination Agreement, will be provided in a Current Report on Form 8-K to be filed by GigCapital8 with the U.S. Securities and Exchange Commission ("SEC") and will be available at www.sec.gov. In addition, PubCo intends to file with the SEC a registration statement on Form F-4 (the "Registration Statement"), which will include a proxy statement of GigCapital8 and a prospectus of PubCo, and GigCapital8 and PubCo will file other documents regarding the Business Combination with the SEC. This communication is not intended to be, and is not, a substitute for the proxy statement/prospectus or any other document that GigCapital8 has filed or that GigCapital8, PubCo or Quantisimo may file with the SEC in connection with the Business Combination.

Advisors

Rimon P.C. is serving as United States legal counsel for Quantisimo, WISeQey and SEALSQ, and Harneys is serving as BVI counsel. DLA Piper LLP (US) is serving as legal counsel for GigCapital8, and Harneys is serving as GigCapital8's Cayman Islands counsel and PubCo's BVI counsel.

About WISeQey

WISeQey Corp. ("WISeQey"), is a British Virgin Islands holding company focused on post quantum cybersecurity, digital identity, space technology and the Internet of Things (IoT). Its operating subsidiaries and technology platforms address distinct parts of this portfolio:

Each subsidiary contributes to WISeQey's mission of securing the internet while focusing on their respective areas of research and expertise. Their technologies seamlessly integrate into the comprehensive WISeQey platform. WISeQey secures digital identity ecosystems for individuals and objects using blockchain, AI, and IoT technologies. With over 1.6 billion microchips deployed across various IoT sectors, WISeQey plays a vital role in securing the Internet of Everything. Trusted by the OISTE/WISeQey cryptographic Root of Trust, WISeQey provides secure authentication and identification for IoT, blockchain, and AI applications. The WISeQey Root of Trust ensures the integrity of online transactions between objects and people. For more information on WISeQey's strategic direction and its subsidiary companies, please visit www.wisekey.com.

About WISeSat.Space

WISeSat.Space is a space technology company focused on secure satellite communications for Internet of Things applications. Its approach combines satellite infrastructure with cybersecurity and digital identity technologies to support trusted communications between connected devices and ground-based systems.

About SEALSQ:

SEALSQ is a leading innovator in Post-Quantum Technology hardware and software solutions. Our technology seamlessly integrates Semiconductors, PKI (Public Key Infrastructure), and Provisioning Services, with a strategic emphasis on developing state-of-the-art Quantum Resistant Cryptography and Semiconductors designed to address the urgent security challenges posed by quantum computing. As quantum computers advance, traditional cryptographic methods like RSA and Elliptic Curve Cryptography (ECC) are increasingly vulnerable.

SEALSQ is pioneering the development of Post-Quantum Semiconductors that provide robust, future-proof protection for sensitive data across a wide range of applications, including Multi-Factor Authentication tokens, Smart Energy, Medical and Healthcare Systems, Defense, IT Network Infrastructure, Automotive, and Industrial Automation and Control Systems. By embedding Post-Quantum Cryptography into our semiconductor solutions, SEALSQ ensures that organizations stay protected against quantum threats. Our products are engineered to safeguard critical systems, enhancing resilience and security across diverse industries.

For more information on our Post-Quantum Semiconductors and security solutions, please visit www.sealsq.com.

About Quantisimo Corp.

Quantisimo Corp. is being developed as a pure-play sovereign quantum vertical platform under the vision "Root to Qubit." Established by WISeQey and SEALSQ, Quantisimo aims to integrate cryptographic roots of trust, post-quantum security, quantum networking, photonic technologies, quantum sensing, quantum computing and secure terrestrial and space infrastructure. Its proposed initial portfolio would comprise interests in Miraex SA, SEALCOIN AG, WeCan Group SA and WISeSat.Space Holdings Corp., with a strategy to expand complementary quantum capabilities through technology development, strategic investments and acquisitions. For additional information, visit https://www.WISeQey.com/.

About GigCapital8 Corp.

GigCapital8 Corp. is a Private-to-Public Equity (PPE)™ company, also known as a special purpose acquisition company, with a Mentor-Investor™ methodology and a mission to partner with a high technology differentiating company to forge a successful path to the public markets through a business

combination. GigCapital8 aims to partner with an innovative company with exceptional leaders in order to create an industry-leading partnership that will be successful for years to come.

Private-to-Public Equity (PPE)™ and Mentor-Investor™ are trademarks of GigManagement, LLC, a member entity of GigCapital Global and affiliate of GigCapital8 Corp., used pursuant to agreement.