Exhibit 99.1 Quantum-Si Reports Fourth Quarter and Full Year 2023 Financial Results Finalizing Commercial Readiness for Expected Full Commercial Launch by the End of Q1 2024 Releases Full Year 2024 Financial Guidance BRANFORD, Conn. -- (BUSINESS WIRE) – Feb. 29, 2024 -- Quantum-Si Incorporated (Nasdaq: QSI) (“Quantum-Si,” “QSI” or the “Company”), The Protein Sequencing CompanyTM, today announced financial results for the fourth quarter and full year ended December 31, 2023. Press Release Highlights ● Record ...