WISeKey and SEALSQ Establish Quantisimo Corp. as a Special Purpose Vehicle, and Execute Letter of Intent with GigCapital8 Corp.

Proposed Strategic Business Public company at $575 Million Initial Enterprise Value with Significant Long Term Growth Potential Through Strategic Acquisitions

Proposed Transaction Intended to Create a Consolidated $2 Billion Trusted Quantum Pure-Play Platform Following Additional Acquisitions

WISeKey International Holding Ltd. (“WISeKey”) (SIX: WIHN; Nasdaq: WKEY), a global leader in cybersecurity and trusted digital ecosystems, and its subsidiary SEALSQ Corp. (Nasdaq: LAES), a leading developer of semiconductors, PKI, and post-quantum technologies, today announced that their jointly established special purpose vehicle, Quantisimo Corp. (“Quantisimo”), has entered into a non-binding Letter of Intent (“LOI”) with GigCapital8 Corp. (Nasdaq: GIW) (“GigCapital8”), a publicly traded Private-to-Public Equity (PPE)™, also known as special purpose acquisition company (SPAC), to explore the establishment of a Nasdaq-listed strategic quantum technology platform.

The proposed transaction contemplates a business combination between Quantisimo and GigCapital8. Upon completion of the transaction, the combined company is expected to have a pre-money enterprise value of approximately $575 million, subject to customary closing conditions. The Parties intend to increase this initial valuation to reach US$2 billion through build-up consolidated acquisitions of up to an additional five quantum companies. The transaction is currently expected to close during the first quarter of 2027.