REG-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

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 * Quantisimo Corp. (“Quantisimo”), established by WISeQey Corp (Nasdaq/SIX: WQEY) (“WISeQey”), a global quantum cybersecurity and space IoT company, and its subsidiary, SEALSQ Corp (Nasdaq: LAES) (“SEALSQ”), a developer of secure semiconductors, public key infrastructure (PKI) and post-quantum security products, is being developed as a pure-play sovereign quantum vertical platform under the vision “Root to Qubit.” Through the proposed contribution of interests in Miraex SA, SEALCOIN AG, WeCan Group SA and WISeSat.Space Holdings Corp. (“WISeSat.Space”) (Nasdaq: SAIQ), a space technology and secure satellite communications company together with selected future quantum technologies and strategic investments, Quantisimo aims to connect the foundations of digital trust with quantum computing, quantum networking and secure terrestrial and space infrastructure. * The definitive business combination agreement follows the letter of intent between Quantisimo and GigCapital8 Corp. (NASDAQ: GIW) (“GigCapital8”), a Private-to-Public Equity (PPE)™ company also known as a special purpose acquisition company (SPAC), announced on June 24, 2026. * Upon closing, WISeQey and SEALSQ will receive an aggregate of 66,610,000 shares of the new publicly listed holding company, Quantisimo Holding Corp. (“PubCo”), implying a pro forma equity value for Quantisimo of approximately $666.1 million at $10.00 per share, and are expected to hold a majority of PubCo’s outstanding ordinary shares. * The transaction is supported by a minimum cash condition of $15 million, to be funded through cash from GigCapital8’s trust account and any PIPE investment, together with a matching cash contribution from SEALSQ. * WISeQey, SEALSQ and GigCapital8’s sponsor have agreed to customary six-month lock-ups, and GigCapital8’s sponsor has agreed to vote in favor of, and not redeem shares in connection with, the transaction. * The business combination is expected to be completed in the first quarter of 2027, subject to customary closing conditions, including approval by GigCapital8’s shareholders, and PubCo’s ordinary shares are expected to list on the Nasdaq Capital Market under the symbol “QSMO.” 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.”