Quantum-Si Inc
Quantum-Si Incorporated (Nasdaq: QSI) is a life sciences company developing and commercializing tools for proteomics research, including instruments and consumables for next-generation protein sequencing. Its proprietary platform uses single-molecule detection to analyze proteins in parallel at amino-acid resolution,… From the company’s description.
Over the twelve months to Sep 30, 2026, Quantum-Si Inc reported revenue of $1.26M, down 60.2% from a year earlier, and a net loss of $85.13M. Operations used $80.91M in cash. In fiscal 2025, it reported revenue of $2.44M, down 20.3% from fiscal 2024, and a net loss of $101.34M.
Margins and return on equity change in ; everything else in percent. Fewer shares and less debt are shown plainly, not as bad news — it depends what you make of buybacks. Dotted labels explain each measure. is shown separately from the annual figures.
What Quantum-Si Inc does
In the company’s own words
Quantum-Si Incorporated (Nasdaq: QSI) is a life sciences company developing and commercializing tools for proteomics research, including instruments and consumables for next-generation protein sequencing. Its proprietary platform uses single-molecule detection to analyze proteins in parallel at amino-acid resolution, helping researchers study protein identity, abundance, variants and post-translational modifications. Products are intended for research use and serve academic and other research laboratories, biopharmaceutical companies, contract development and manufacturing organizations, government and industrial customers. The current product line includes Platinum and Platinum Pro instruments, library preparation and barcoding kits, sequencing kits, and Platinum Analysis Software for sequencing-data analysis and visualization. The company is also developing Proteus, a next-generation platform designed to increase sequencing output and sample throughput and automate workflow and analysis. Quantum-Si operates as a single business focused on proteomics rather than reporting multiple business segments. It was founded in 2013 as Q-SI Operations and became Quantum-Si Incorporated through a 2021 business combination with HighCape Capital Acquisition Corp. Revenue for the year ended December 31, 2025 was not stated in the provided text.
Company details
- Sector
- Health Care
- Industry (SIC)
- Medical Instruments
- Headquarters
- BRANFORD, CT
- Fiscal year end
- December
- CIK
- 1816431
- SIC
- 3829
Financial performance, year by year
Fiscal 2021–2025 · USDThe full income statement, balance sheet and cash flow for each of these years — every figure traceable to its filing — is on the Financials tab with a free account.
Who owns Quantum-Si Inc — and what changed
Funds as of 2026Q2 · superinvestors as of 2026-06-30
Largest fund holders · Quantum-Si Inc’s weight in each
Fund ownership is a floor, not a census — pensions, insurers and people holding shares directly are not visible here.
Fund ownership counts N-PORT filers only, so it is a floor rather than a census — pensions, insurers and direct holders are not visible here, and the remainder is not “held by individuals”.
Could not be determined for this company: bond issues.
Every fund and institutional holder, quarter by quarter, is on the Ownership tab with a free account.
Recent filings
All filings →Each filing opens into its own statements and disclosures here.
Put this business in context.
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