Exhibit 99.1 Quantum-Si Reports Third Quarter 2025 Financial Results Announces Successful Sequencing on Prototype Proteus Unit, Development Program Remains On-Track BRANFORD, Conn. -- (BUSINESS WIRE) -- November 5, 2025 -- Quantum-Si Incorporated (Nasdaq: QSI) ("Quantum-Si," "QSI" or the "Company"), a proteomics technology company redefining protein analysis through single- molecule detection, today announced financial results for the third quarter ended September 30, 2025. Press Release Highlights Total op ...