Exhibit 99.1 Quantum-Si Reports First Quarter 2026 Financial Results and Highlights Proteus Development Milestones TM Successful sequencing on integrated Proteus instruments and continued progress toward amino acid coverage and overall launch capabilities BRANFORD, Conn. -- (BUSINESS WIRE) -- May 7, 2026 -- Quantum-Si Incorporated (Nasdaq: QSI) ("Quantum-Si," "QSI" or the "Company"), a proteomics technology company redefining protein analysis through single-molecule protein sequencing, today announced finan ...